The Uplift Blog
GrowthBook Version 3.4
It’s been 2 months since our last release, and we’re excited to bring you some highly requested features to kick off the new year. This release includes over 150 changes, and we’ve highlighted some of the biggest ones below.
Custom Fields and Experiment Templates

GrowthBook has always been flexible with custom tags and full markdown support, but now we’re making it even easier to standardize your workflows.
- Custom Fields: Define your own fields for feature flags and experiments. Link to Jira tickets, tag impacted product surfaces, and enforce team-wide documentation standards.
- Experiment Templates: Configure default values for all experiment fields, including hypothesis, tags, targeting conditions, metrics, and more. Create templates for different types of experiments your team runs. When starting a new experiment, your team can use a template, with the option to make this step mandatory for consistency.
These features help enforce consistency and structure across your entire organization, and we’re really excited to see all the ways they get used!
Available to all Enterprise customers. Read more about Custom Fields and Experiment Templates in our docs.
Shareable Experiment Reports

Need to share experiment results with stakeholders outside GrowthBook? Now you can generate public shareable links for specific experiments.
- Defaults to private, but you can opt in to share on an experiment-by-experiment basis
- Share insights in your company Slack, collaborate with external partners, update leadership, or even showcase big wins on LinkedIn.
Read more about Shareable Reports in our docs. This feature is available to all organizations, both free and paid.
New Metrics - Retention, Count Distinct, and Max
We’ve added new kinds of metrics you can define on top of Fact Tables.
- Retention: Measure the percentage of users who return within a specific time window. For example, a “Week 2 Retention” metric that tracks the percentage of users who engaged with your app 7-14 days after seeing your experiment.
- Count Distinct: Aggregation option for mean, ratio, and quantile metrics. For example, a “Unique Videos” metric that counts all of the distinct video ids a user watched, ignoring repeats.
- Max: Aggregation option for mean, ratio, and quantile metrics. For example, a “High Score” metric that measures the highest score each user obtained in your game, no matter how many attempts it took to get there.
Retention metrics are available to Pro and Enterprise customers, and the new aggregation options are available to all organizations, both free and paid. Read more about these New Metrics in our docs.
Environment Forking
When creating a new environment, you can now choose a parent environment to “fork” from - for example, creating a new Staging environment that is a fork of Production. This will copy all feature flag rules so the new environment starts out as an exact clone of the parent. After that point, the environments will be treated independently.
Environment forking becomes really powerful when combined with our REST API. For example, your CI/CD pipeline could fork a new ephemeral environment for each PR and automatically clean it up when the PR is closed.
The UI for manually creating new environment forks is available to all organizations, but programmatic access via the API is only available to Enterprise customers. Read more about environment forks in our docs.
CMS Integrations - Contentful and Strapi

A/B testing inside your CMS just got easier. We now support Contentful and Strapi, two of the most popular headless CMS platforms.
Read our new guides for Contentful and Strapi to see how easy it is to experiment with your CMS content. We’d love to add more integrations like this in the future, so let us know which ones you most want to see!
Updated Node.js and Edge SDKs
We’ve made some huge changes to our JavaScript SDK to better support server-side applications. The new `GrowthBookClient` class is up to 3x faster and more memory efficient for Node.js applications. Read the new Node.js SDK docs or check out specific tutorials for Express.js or Deno/Hono.
We also revamped our Edge SDKs to be more flexible. New Lifecycle Hooks let you perform custom logic at various stages. This allows for custom routing, user attribute mutation, header and body (DOM) mutation, and custom feature flag and experiment implementations – while still preserving the ability to automatically run Visual and URL Redirect experiments and SDK hydration.
Simulate Features

Way back in GrowthBook 2.5, we launched Archetypes to help you simulate how a specific feature flag behaves for a set of user attributes. Now there is a dedicated landing page for managing archetypes, along with a new “Simulate” section. Now, you can simulate all your feature flags at once and instantly verify how features will behave for any user.
The ability to simulate features is available to all Pro and Enterprise customers, but saving user attributes as a reusable “Archetype” is available only to Enterprise customers.

The Best A/B Testing Platforms of 2025: Features, Comparisons, and Expert Recommendations
Imagine making every product decision with data, powered by the best A/B testing platforms of 2025. These tools have become essential for businesses hungry to innovate faster and build with confidence. This new generation of tools prioritizes performance, flexibility, and organization-wide applicability, ushering in a paradigm known as experimentation-driven development. No longer confined to marketing departments, A/B testing is now a cornerstone for entire product teams. In this guide, we’ll explore key platforms, focusing on their strengths, limitations, and suitability for different needs. By the end, you’ll have a clearer understanding of which platform is right for your organization.
Modern Platforms: Innovating for Today’s Needs
GrowthBook: Experimentation-Driven Development at its best
We built GrowthBook to be the tool we always wished we had—one that balances developer-friendly workflows with robust experimentation capabilities. We excel in flexibility, scalability, and developer-friendly features, and we seamlessly integrate feature flagging and A/B testing to deliver unmatched usability and precision. Picture your team quickly toggling features while running precise experiments—all within a platform that feels like it was designed just for developers. Here's where GrowthBook is unique:
- Warehouse-Native Integration: GrowthBook integrates directly with your existing data warehouse, ensuring low-latency experiment evaluations and reliable metrics.
- Open-Source and Self-Hosting Options: Ideal for industries with stringent compliance and data sovereignty requirements, GrowthBook’s open-source nature empowers teams to self-host if needed.
- Developer-First Approach: Robust SDKs, CI/CD compatibility, and transparent SQL insights allow engineering and data teams to fine-tune experiments with precision.
- Seamless Integration: GrowthBook easily fits into existing workflows, leveraging tools you already use to maximize ROI.
With a focus on unlocking experimentation-driven product development, we're the trusted choice for teams aiming to scale innovation while maintaining performance.
Statsig: All-in-One Simplicity with Limits
Statsig provides A/B testing, feature flagging, and session recording in a unified platform. While it’s sufficient for teams seeking a simple, all-in-one solution, its statistical methods, while including features like CUPED, may not be as robust as those offered by platforms specifically designed for data scientists. For example, it lacks flexibility in supporting different types of experiments, such as those with very large or very small user bases. The platform’s rising costs, especially when scaling beyond the initial 5 million events included in the Pro plan, make it less appealing. Additionally, its limitations in integrating with data warehouses may not meet the needs of organizations with sophisticated data practices
Eppo: Statistical Precision for Data-Driven Teams
Eppo shines in its statistical depth, offering precise and actionable experiment results. Its warehouse-native architecture aligns with organizations that prioritize high-quality experimentation. However, Eppo’s feature flagging functionality, while supporting core features such as feature gates and rollouts, may not be as comprehensive as some competitors'. For example, it may lack advanced features like user segmentation or real-time monitoring found in more mature platforms. For data-driven organizations primarily focused on experimentation, Eppo provides an excellent foundation. However, teams seeking a broader feature flagging toolset with more advanced capabilities may need to consider alternatives.
Legacy Platforms: Struggling to Keep Up
LaunchDarkly: Feature Management First, Experimentation Second
LaunchDarkly excels in feature flagging but treats A/B testing as an afterthought. This lack of integration can lead to a clunky user experience, making it less suitable for teams aiming for seamless experimentation workflows.
Optimizely: High Costs, Fragmented Experience
Once a market leader, Optimizely now faces challenges with its high pricing and fragmented user experience. While its A/B testing capabilities remain robust, the platform’s cost makes it viable only for large enterprises. Compared to Optimizely, GrowthBook reduces both cost and complexity.
Adobe Target: Limited Flexibility in a Closed Ecosystem
Adobe Target is tightly integrated into Adobe’s ecosystem, making it a logical choice for existing Adobe customers. However, its high costs and lack of flexibility make it less appealing for agile teams seeking modern experimentation workflows. GrowthBook is a clear alternative to Adobe Target, with warehouse-native analytics.
Other Platforms: Niche Capabilities
PostHog: Lightweight Analytics with Basic Experimentation
PostHog focuses on product analytics and offers basic experimentation features. While its open-core model appeals to startups, the platform’s limited self-hosting capabilities and lightweight experimentation tools make it less suitable for teams with advanced needs. For advanced experimentation and robust feature flags, consider GrowthBook compared to PostHog.
Choosing the Right Platform
When choosing an A/B testing platform, think about what matters most to your organization. Are you looking for scalability, compliance, or seamless integration with your current tools? Matching these priorities with the right platform can make all the difference.
- For advanced experimentation workflows: GrowthBook delivers unmatched flexibility, scalability, and developer-first features.
- For data teams: Eppo offers statistical rigor and warehouse-native integration but falls short with limited feature flagging capabilities, making it less ideal for teams needing a comprehensive solution.
- For all-in-one solutions: Statsig provides simplicity but may not scale with advanced needs.
- For feature flagging-first teams: LaunchDarkly suffices but lacks depth in experimentation.
- For legacy ecosystem users: Optimizely and Adobe Target remain options, albeit costly and limited in flexibility.
- For lightweight needs: PostHog provides budget-friendly analytics-driven tools for smaller teams.
Conclusion
Innovation thrives on experimentation—it’s how teams transform ideas into measurable success. Choosing the right A/B testing platform can accelerate your ability to iterate, scale, and innovate. GrowthBook’s modular design makes it perfect for organizations aiming to scale. Imagine starting with basic experiments and effortlessly expanding into enterprise-grade workflows—it’s a platform built to evolve with your team’s needs. Whether you’re prioritizing compliance, advanced experimentation, or seamless developer integration, GrowthBook’s strengths make it the clear leader in the 2025 A/B testing platform landscape.
Ready to scale your experiments?
Get started with GrowthBook for free today.

Move Fast Without Breaking Things: How GrowthBook and Rollbar Empower Product and Ops Teams
As technology evolves at breakneck speed, staying ahead means constantly innovating. Product teams are always experimenting with new features to improve user experiences, while operations teams focus on keeping systems reliable and performant. But what happens when experimentation introduces risks—like unexpected errors or performance issues?
That’s where the integration of GrowthBook’s feature flagging and Rollbar’s error monitoring comes in. Together, they empower product and ops teams to collaborate effectively, innovate confidently, and safeguard user experiences.
Innovate Confidently With Real-Time Error Monitoring
GrowthBook’s feature flags make it easy to roll out features or experiments to specific user segments. Rollbar’s real-time error monitoring ensures you’re alerted immediately if something goes wrong, allowing your team to make fast, informed decisions.
Example: Imagine you’re rolling out a new recommendation algorithm to 10% of users. Rollbar detects an issue affecting a specific browser. With GrowthBook, you can disable the feature for those users instantly, without impacting the rest of the rollout. It’s experimentation without unnecessary risk.
Experiment Without Disruptions
Ops teams often face a tough trade-off between moving fast and keeping systems stable. By integrating Rollbar with GrowthBook, you create a safety net for experiments. With feature flags, your team can quickly address issues without waiting on a developer to ship a fix.
Clear Insights for Continuous Improvement
Both product and ops teams rely on data to refine their strategies. The GrowthBook and Rollbar integration gives you visibility into how new features and experiments impact your application’s performance. With these insights, you can iterate faster and more effectively, making adjustments with precision.
Key Benefit: Use real-time data to confidently refine your experiments and features.
Building Confidence in Experimentation
Innovation doesn’t happen without experimentation, but for experimentation to thrive, it needs buy-in across the organization. GrowthBook and Rollbar make this easier by combining robust monitoring with the flexibility of feature flags. Teams can move quickly while still prioritizing reliability, making experimentation a safe, scalable part of your growth strategy.
Faster, Safer Innovation Starts Here
Product and ops teams need tools that let them move quickly without sacrificing quality. The GrowthBook + Rollbar integration is built for exactly that. It’s the ultimate way to deliver user experiences that delight while keeping your systems stable.
Want to see it in action? Learn more about the integration and discover how GrowthBook and Rollbar can help your team innovate smarter and safer.

Introducing Multi-Armed Bandits in GrowthBook
Bandits have been released in beta as part of GrowthBook 3.3 for Pro and Enterprise customers. See our documentation on getting started with bandits.
Multi-armed bandits allow you to test many variations against one another, automatically driving more traffic towards better arms, and potentially discovering the best variation more quickly.
Bandits are built on the idea that we can simultaneously…
- … explore different variations by randomly allocating traffic to different arms; and
- … exploit the best performing variations by sending more and more traffic to winning arms.

In online experimentation, bandits can be particularly useful if you have more than 4 variations you want to test against one another. Scenarios where bandits can be helpful include:
- You are running a short-term promotional campaign, and want to begin driving traffic to better variations as soon as there is any signal about which variation is best.
- You have many potential designs for a call-to-action button for a user sign-up, and you care more about just picking the best flow that leads to sign-up.
Furthermore, bandits work best when:
- Reducing the cost of experimentation is paramount. This is true in cases like week-long promotions, where you don’t have time to test 8 versions of a promotion and then launch it, so you want to test 8 versions and begin optimizing after just a few hours or on the first day.
- You have a clear decision metric that is relatively stable. Ideally, your decision metric should not be an extreme conversion rate metric (e.g. < 5% or > 95%), or if it’s a revenue metric, you should apply capping to prevent outliers from adding too much variance.
- You have many arms you want to test against one another, and care less about learning about user behavior on several metrics than about finding a winner.

Read more about when and how to use bandits in our documentation.
The following table provides an summary of the differences between bandits and standard experiments.
What makes GrowthBook’s bandits special?
GrowthBook's bandits rely on Thompson Sampling, a widely used algorithm to balance exploring the value of all variations while driving most traffic to the better performers. However, our bandits differ in a few ways that ensure they work well in the context of digital experimentation.
Consistent user experience
Some bandit implementations do not preserve user experience across sessions, making them tricky to use when a stable user experience is important. Because bandits dynamically update the percentage of traffic going to each variation, if you run it on users who return to your site or product and do not preserve their user experience, they may be exposed to multiple variations over the course of a bandit.
This can lead to:
- Bad user experiences where your product frequently changes for an individual customer.
- Biased results.
GrowthBook uses Sticky Bucketing, a service that allows you to store user variations in some service, such as a cookie, so that when they return, they always get the same experience, even when the bandit has updated variation weights.
Setting up Sticky Bucketing in our HTML SDK is as easy as adding a parameter to our script tag.
<script async data-client-key="CLIENT_KEY" src="<https://cdn.jsdelivr.net/npm/@growthbook/growthbook/dist/bundles/auto.min.js>" data-use-sticky-bucket-service="cookie"></script>Implementing Multi-Armed Bandits in GrowthBook
Accommodates changing user behavior
GrowthBook’s bandits use a weighting method to prevent changing user behavior over time from biasing your results.
What is the issue? As your bandit runs, two things are changing: your bandit updates traffic allocations to your variations, and the kind of user entering your experiment changes (e.g., due to day-of-the-week effects). The correlation between these two can cause biased results if not addressed.
Imagine the following scenario:
You run a bandit that updates daily. You start your bandit on Friday and you have two variations that have a 50/50 split (100 observations per arm). You observe a 45% conversion rate in Variation A, and a 50% conversion rate in Variation B. After the first bandit update, the weights become 10/90 (just as an illustration, the actual values would be different). The total traffic on Saturday is also 200 users, but this time Variation B gets 90% of the traffic. Conversion rates on weekdays tend to be higher than on weekends, regardless of variation. On Saturday, you observe a 10% conversion rate in Variation A and a 15% conversion rate in Variation B. On both Friday and Saturday, Variation B has larger conversion rates, but if you naively combine the data across both days, Variation A looks like the winner:
The combined conversion rate for Variation B is 27.5%, while for Variation A it is 39%, despite Variation B outperforming Variation A on both days of the experiment. Clearly, something is wrong here. In fact, sharp-eyed readers might notice this is a case of Simpson’s Paradox.
How did we solve it? We use weights to estimate the mean conversion rate for each bandit arm under the scenario that equal experimental traffic was assigned to each arm throughout the experiment. In this scenario, we can recompute the observed conversion rates as if the arms received equal traffic (e.g., on Saturday we had 10/100 conversions instead of 2/20). Using these adjusted conversion rates, the combined conversion rates now make sense:
Variation B is now the winner. By accounting for changes in overall traffic each day, the combined conversion rate now appropriately reflects differences in conversion rates and traffic variation over time. Our bandit applies a similar logic to ensure that day-of-the-week effects and other temporal differences do not bias your bandit results.
Built on a leading warehouse-native experimentation platform
GrowthBook is the leading open-source experimentation platform. It is designed to live on top of your existing data infrastructure, adding value to your tech stack without complicating it.
GrowthBook integrates with BigQuery (GA4), Snowflake, Databricks, and many more data warehouse solutions. If your events land in your data warehouse within minutes, then GrowthBook bandits can adaptively allocate traffic within hours or less.

Get started
To get started with Bandits in GrowthBook, check out our bandits set-up guide, or if you’re new to GrowthBook, get started for free.
GrowthBook Version 3.3
We’ve been hard at work on GrowthBook version 3.3, which includes Multi-Arm Bandits, powerful new metric capabilities, a new design system, and an exciting announcement! Here’s everything you need to know:
Multi-Arm Bandits

Multi-Arm Bandits are experiments that dynamically allocate traffic to maximize efficiency, sending more traffic to top-performing variations as tests run. This minimizes losses and reduces risks when testing multiple variants.
Multi-Arm Bandits were months in the making and we're excited to share it with everyone. Bandits are currently in beta and available to all Pro and Enterprise customers.
Metric Improvements
In this release, we've made huge improvements to every aspect of metrics and fact tables. We don't have room to list them all, but here are a few highlights.
Metric Groups
Save and organize groups of metrics so you can streamline experiment setup. Groups are passed by reference so updates will apply to all experiments using the group. You can also adjust the order in which metrics are shown:

Live SQL Preview
Now available when creating or editing fact table metrics, so you can see how metrics behave under the hood in real time.

Inline and User Filters
Simplify the UI and enable a new class of metrics for fact tables that were previously impossible. Learn more

These upgrades empower you to create, organize, and analyze metrics more efficiently than ever before.
New Design System
We've started migrating GrowthBook to a new design system built on Radix UI. While this work is ongoing, you’ll already notice slicker visuals, better keyboard navigation, and improved Dark Mode support!
🚀 Built-in Managed Warehouse (coming soon)
Not every team has the resources to set up and maintain its own data warehouse, which is why we’re launching a fully managed ClickHouse option within GrowthBook Cloud!
This Built-in Warehouse sits on top of our existing SQL and stats engine, so it’s fully compatible with all of our advanced experimentation settings, and you’ll automatically benefit from ongoing improvements to our Warehouse-Native offering.
We have a limited number of spots in our private beta, so reach out if you’re interested in being among the first to try it out!

Announcing GrowthBook on JSR
GrowthBook is committed to supporting modern platforms, bringing advanced feature flagging and experimentation to where you are. We’re excited to announce the availability of our JavaScript SDK on JSR, the modern open-source JavaScript registry. This integration empowers JavaScript and TypeScript developers with a seamless experience for implementing and managing feature flags in their applications.
JSR simplifies the process of publishing and importing JavaScript modules, offering robust features like TypeScript support, auto-generated documentation, and enhanced security through provenance attestation. This collaboration brings these benefits to GrowthBook users, streamlining the integration and utilization of feature flagging in their development workflows.
Using the GrowthBook JS SDK via JSR offers an excellent developer experience, with first-class TypeScript support, auto-generated documentation accessible in your code editor, and more.
How to Install GrowthBook from JSR
Get started with GrowthBook using the deno add command:
deno add jsr:@growthbook/growthbookOr using npm:
npx jsr add @growthbook/growthbookThe above commands will generate a deno.json file, listing all project dependencies.
{
"imports": {
"@growthbook/growthbook": "jsr:@growthbook/growthbook@0.1.2"
}
}deno.json
Use GrowthBook with Express
Let’s use GrowthBook with an Express server. In our main.ts file, we can write:
import express from "express";
import { GrowthBook } from "@growthbook/growthbook";
const app = express();
app.use(function (req, res, next) {
req.growthbook = new GrowthBook({
apiHost: "<https://cdn.growthbook.io>",
clientKey: "sdk-qtIKLlwNVKxdMIA5",
});
req.growthbook.setAttributes({
id: req.user?.id,
});
res.on("close", () => req.growthbook.destroy());
req.growthbook.init({ timeout: 1000 }).then(() => next());
});
app.get("/", (req, res) => {
const gb = req.growthbook;
if (gb.isOn("my-boolean-feature")) {
res.send("Hello, boolean-feature!");
}
const value = gb.getFeatureValue("my-string-feature", "fallback");
res.send(`Hello, ${value}!`);
});
console.log("Listening on port 8000");
app.listen(8000);Finally, you can run the following command to execute:
deno -A main.tsDepending on how you’ve set up your feature flags in GrowthBook (sign up for free), the response will be different:

Check out our official docs to learn more about feature flags, creating and running experiments, and analyzing experiments.
What’s next?
With GrowthBook's JS SDK now on JSR, it’s even easier to bring the power of feature flags and A/B testing to any JavaScript environment.
- Check out JSR, the JavaScript registry built for the modern web.
- Read the announcement on Deno's blog.
- Learn more about GrowthBook’s JS SDK.

5 Ways to Use Feature Flags for Smarter Releases
At their most basic, feature flags are like light switches: they let you turn features on and off. But behind this simple function lies a world of possibilities. With feature flags, you can ship faster, reduce risk, and deliver personalized experiences without constant code changes or complicated deployments. In this guide, we’ll explore 5 essential ways to use feature flags in GrowthBook to optimize your software development process and ship smarter.

1. A/B Testing
One of the most common use cases for feature flags is to power A/B tests. A/B testing lets you compare a control (your current version) with one or more variants to see which performs better. Whether you're optimizing call-to-action copy, testing pricing models, or tweaking product recommendations, A/B testing helps you make data-driven decisions.

Example: Testing Calls to Action
Pretend you have a coffee company called, Split Bean, founded by former nuclear physicists. Their current homepage headline, "Engineered for Perfection: Coffee Crafted by Scientists," communicates their unique story. But what if a punchier headline would sell more beans? Time to set up a test to find out.

- Create a Feature Flag: In GrowthBook, navigate to the Features section and create a new feature called
headline. Set the default value to your current headline.

- Add an Experiment: After saving the flag, add an Experiment Rule to split traffic between your original headline and the new variant. For a punchier approach, we’ll try “Aromas That’ll Slap You Awake Faster Than a Cold Shower.”



- Analyze the Experiment: We'll need to wait for some customers to visit, but which version do you think will win?
A/B testing is a powerful way to ensure you’re making decisions based on real data, which is key to driving engagement and loyalty, and feature flags make it easy to deliver tailored experiences to different user segments, and, in turn, provide a better product for your customers. 💪
2. Personalization with Feature Flags
Personalization is the key to driving engagement and loyalty, and feature flags make it easy to deliver tailored experiences to different segments of users.
Example: Rolling Out a Custom Blend Feature
Our favorite coffee company, Split Bean, has launched a custom-blend feature that lets users choose beans, roast levels, and artwork.
But this new feature isn’t available to just anyone—initially, it was only available to US customers on an annual subscription. Feature flags offer a streamlined way to restrict custom blends to only these customers.
- Create a Feature Flag: Set up a
custom-blendflag that defaults to false. - Add Targeting Rules: Use GrowthBook’s Forced Rules to define who can see the feature—users in the US with an annual subscription.

Wondering where the location and subscription values come from? In GrowthBook, define these attributes via SDK Configuration → Attributes. Then, in your app, pass these same attributes to your GrowthBook instance. Go to docs.
By using feature flags, Split Bean can easily manage who gets access to their custom blend feature and refine their marketing efforts with precision.

This level of personalization can be applied to various scenarios, from displaying cookie banners based on location to offering exclusive content for premium subscribers.
3. Targeted Releases
When rolling out a new feature, testing with a small, trusted group of users first is a smart way to catch potential issues. This is where targeted releases come in handy.
Example: Split Bean Coffee Review
Split Bean is launching a new features section to showcase all the glowing reviews from their customers. While adding the section seems relatively straightforward, it requires several moving parts: database calls, responsive styling, and the inclusion of user-generated content—all of which could break unexpectedly!

By using feature flags, Split Bean can release the feature to internal beta users.
- Like before, create a feature flag. Call it
show-reviewswith a default value of false, so the reviews will be off for all users. - Add a Forced Rule, set the value to true, and define rules so that reviews show when a user’s company is Split Bean and their beta attribute is true.

Save these changes and publish the updated feature flag. When internal beta users visit the site, they'll see the new review section and—importantly—see if anything has gone disastrously wrong 🙃
Once you're confident the feature works as expected, you can gradually expand access to a larger audience, mitigating risks along the way.
4. Canary Releases

Even with thorough testing, releasing a major feature to all users at once can be risky. Engineers know this truth all too well. A canary release helps reduce this risk by rolling out the feature to a small percentage of users first.
Until the mid-1980s (!), miners used actual caged canaries to test for clear and odorless poisonous gases that would kill the small birds before the miners. This grim history gave rise to the saying "canary in the coal mine" and, by extension, a "canary release," which is likewise used as an early-detection method for bugs.
Example: Percentage Rollout
Split Bean is launching a new multi-page checkout flow, designed to reduce cart abandonment. The new flow passed A/B tests and beta testing, but there’s still a chance things could go sideways. With a canary release, Split Bean enables the new checkout for just 5% of users to monitor for any unexpected issues.
- Create a Feature Flag: Set up a
new-checkout-flowflag in GrowthBook. - Add a Rollout Rule: Assign the new flow to 5% of users. As you gain confidence in the feature’s stability, gradually increase the rollout.

When the rollout hits 100%, remove the flag and make the change permanent in the codebase. This approach lets you catch potential issues early, making for smoother, low-stress releases.
5. Operational Flags
Finally, feature flags aren’t just for new features—they also give you powerful operational control over your app. One key use case is the kill switch ☠️ , which allows you to quickly disable problematic features in case of emergencies.
Example: Payment Integration Kill Switch
Split Bean’s CEO just made a deal with a new payment processor to save a few points per transaction. While the engineering team seems to have integrated it without issue, what happens if it fails during a high-volume period? That’s a lot of beans to lose.
With GrowthBook, every feature flag comes with a built-in kill switch. If something goes wrong, you can toggle the new-payment-processor flag off instantly to prevent further issues and revenue loss.

In addition to kill switches, operational feature flags can be used for things like maintenance mode, where you temporarily disable parts of your app during an update. Just like Apple’s “Be right back” message during product launches, Split Bean can set a flag to pause sales while it announces new blends.

Making it possible for anyone to categorically change your app at the literal flick of a switch might seem risky in itself. GrowthBook provides the ability to add a confirmation pop-up to the switch to prevent accidental clicks. Go to Settings → General → Feature Settings → Require confirmation when changing an environment kill switch.
Conclusion: Ship Faster and Smarter with Feature Flags
Feature flags offer more than just an on/off switch—they provide a flexible and powerful way to manage your app’s features and optimize user experiences. From A/B testing to canary releases and operational controls, feature flags in GrowthBook let you ship faster, reduce risk, and stay ahead of the competition.
Get Started Today: Create a free account, and see how easy it can be to build and deploy smarter!

Convincing Leadership to Adopt A/B Testing
Many of today's leading companies rely on A/B testing to measure the impact of product changes and remove guesswork from decision-making, allowing teams to make data-driven decisions rather than relying on intuition. Changing from an intuition-based process to an experimentation-driven one can be difficult, especially without buy-in from leadership. Getting buy-in from leadership is the single largest determinant for a successful experimentation program. This post outlines a strategic approach to gain buy-in from leadership, starting small and demonstrating measurable impact.
Highlight the Value of A/B Testing
The first step in convincing leadership is to present A/B testing as a tool for continuous improvement rather than an extra burden. Here are a few key points to emphasize:
- Data-Driven Decision Making: A/B testing replaces guesswork with data, allowing the company to make informed decisions based on user behavior and preferences. It’s an objective way to measure the impact of product changes.
- Reduced Risk of Launching Ineffective Features: By testing new features on a small subset of users before rolling them out widely, you minimize the risk of launching something that doesn't resonate with users or hurts performance.
- Impact on Metrics that Matter: Connect A/B testing to the company’s core KPIs (e.g., conversion rates, user retention, revenue growth). Demonstrate how it can directly impact the metrics that leadership cares about most.
Start Small and Show Results
It’s often easier to get buy-in for something new when the initial investment is low. Start by running a few small-scale tests that are low-risk but have the potential for noticeable results. This strategy builds momentum and shows leadership the tangible benefits of A/B testing without requiring a major overhaul of the existing product development process.
Example: Improving Conversions with a Website Change
In one of our recent experiments, we tested a reordering of elements on our Getting Started page. The goal was to see if changing the layout could improve engagement, specifically how many new accounts were created by an organization after sign-up.
We ran the A/B test for three weeks, comparing the old design to the new one. The result? A 25% increase in the number of accounts that created an organization. Even more exciting, those accounts were 200% more likely to convert into paying customers than those with the older layout. This experiment was part of a series of iterative tests, demonstrating how small changes, backed by data, can have a large impact on core business metrics.
Steps
Step 1: Identify a Feature or Project
Select a feature or project where the impact is uncertain and where developers are open to testing. Ideally, this is a feature that has not yet started or there is some concern about its impact. Choose a feature that’s tied to an important KPI for the business and gets enough traffic to generate results within 2 weeks.
Step 2: Integrate Testing into the Product Development Workflow
Float the idea of running an A/B test for this project and have the test integrated into the launch plan. Pick the goal metrics and estimate the experiment duration, given the power needed to detect the expected effect. Let the team know that should the experiment fail, you will likely roll back the feature and try again (or move on). The goal is to demonstrate how seamlessly A/B testing can be integrated into the product development workflow, enabling smarter decisions without slowing the process.
Step 3: Share Results
Once a few small tests have been completed and shipping decisions have been made based on the results, it's time to communicate this to leadership. Experiment review meetings can help demonstrate that the results, while sometimes counter-intuitive, are valuable. Be sure to communicate:
- The hypothesis behind the test and the variants (with screenshots if applicable).
- The results, including the impact on key metrics.
- What decisions did you make based on this data? (shipped, rolled back, reworked)
- How can these insights inform future product decisions?
Make sure to highlight wins and losses - use the language of 'saves' for features that have a negative impact on metrics. These projects were prioritized, and you might not have realized their negative effects without testing.
Address Leadership Concerns
Leadership may have concerns about adopting A/B testing. Here are some concerns and how to address them:
- Time and Resources: Leaders might worry that A/B testing will slow down product development or require too many resources. Reassure them that, when implemented strategically, A/B testing can streamline decision-making and lead to more effective use of resources by focusing on rapid iterations and MVPs to test that either verify or contradict a hypothesis.
- Concern with Iterative Development: Some leaders may believe that truly innovative products are not created with iterative processes like experimentation-driven development. Counter this by emphasizing that A/B testing allows the company to take calculated risks and learn quickly before investing heavily. There are no projects that cannot be tested in some ways to measure interest, even if they are wildly innovative.
- Cultural Resistance: Sometimes, leadership may resist shifting from intuition-driven decisions to a data-driven culture. In these situations, positioning A/B testing as a tool to enhance rather than replace intuition can help. A/B testing provides a feedback loop that sharpens decision-making.
Build a Culture of Experimentation
Once you’ve successfully demonstrated the value of A/B testing on a small scale, the next step is to foster a culture of experimentation. Encourage leadership to see A/B testing as an ongoing process that fuels innovation and continuous improvement. Over time, teams will become more comfortable using A/B testing to validate decisions and optimize the user experience.
- Make Testing Routine: Incorporate A/B testing into every product development cycle as a natural part of the process.
- Encourage Cross-Department Collaboration: A/B testing should be embraced by product teams and marketing, design, and engineering. When different departments are aligned around experimentation, the results are more impactful.
- Celebrate Wins and Learn from Losses: Recognize successful tests and the insights gained from failed ones. A/B testing is about learning, not just about winning.
Quantifying the ROI of A/B Testing
Leadership often wants a clear financial justification for investing in an experimentation program. Unfortunately, the ROI for experimentation is a complicated number. A/B testing can be used for optimizations or more straightforward A/B tests where the impact of the results is very clear (and definitely communicate those). However, it is hard to determine the ROI of spending 3 months building something that, through an iterative testing program, is more successful than if you had built based on intuition. It can be hard to quantify how much time was saved by not building a feature as well. Also, even failed tests provide value by preventing the launch of potentially harmful features and allowing your team to learn what your users like. Remind leadership that every test provides insights that can drive smarter decisions in the future. Experimentation programs done well maximize learnings, the effects of which can be hard to put a number on.
Conclusion
Convincing leadership to adopt A/B testing requires a thoughtful, measured approach. By starting small, demonstrating clear impact, and integrating testing into the product development, you can build trust in the methodology. Over time, A/B testing can become an essential part of decision-making, leading to better products and stronger results.
If you’re looking to introduce A/B testing into your company, remember: start simple, stay aligned with business goals, and showcase results, no matter how small. In doing so, you’ll not only convince leadership but also set the foundation for a culture of data-driven innovation.

GrowthBook Version 3.2
We’re proud to announce the release of GrowthBook 3.2. This release includes many requested improvements to Saved Groups, experiment alerting, metrics, and the visual editor, among others.
Check out the full details of this release below—and stay tuned for some major features we’re working on that will be coming very soon!
Big Saved Groups

Saved Groups in GrowthBook are a great way to target users by ID or email, but the UI and SDK implementations made it difficult to scale beyond a few dozen values. In this release, we’ve made several changes to better support this use case.
- There’s a brand new UI for managing Saved Groups with CSV upload support, searching and browsing IDs with pagination, and other quality of life improvements.
- A new setting for SDK Connections lets you pass Saved Group values by reference. This optimization can drastically reduce the payload size sent to SDKs when you frequently reuse groups across multiple features or experiments. Passing values by reference is currently supported only in JavaScript and React SDKs, but the rest will be supported soon.
- You can now restrict Saved Groups to specific projects. This is especially useful for larger organizations with many teams that want to better organize their Saved Groups.
Experiment Significance Alerts

We completed a big overhaul of our webhook notification system, which will allow us to rapidly add support for new events and filtering capabilities going forward. First up is one of our most requested features—the ability to alert when a goal metric in an experiment reaches significance. You can now configure alerts for this event and send them to Slack, Discord, or a custom endpoint.
Keep an eye out for new events as we add them, and let us know what you’d most like to see next! We’re super excited about all of the new use cases this will unlock.
Metric Insights

We made two big changes to metrics in this release. First, we added graphs to fact metrics. After creating a fact metric, you can now run an analysis that will look at recent data and display several helpful graphs depending on the metric type. For mean metrics, for example, we show an overall count, daily average, daily sum, and a histogram of metric values. This can help you verify that the metric is set up correctly and reporting the values you expect before adding it to an experiment.
Secondly, we revamped the Recent Experiments list on metric pages. You can now sort by different columns, and, most importantly, there is a new column for Lift, which shows how much the metric changed in each experiment. This lets you answer a critical question—which experiments had the biggest impact on my metric?
Visual Editor Improvements

We’ve been making a number of UX improvements to the visual editor over the past month to make it easier to use and less error-prone. The most noticeable change is the ability to edit element text directly on the page. Just double-click on any text element and start typing!
We have a lot more exciting changes planned here, so stay tuned!
Vercel Integration

GrowthBook has always had first-class support for Vercel and the Next.js ecosystem (it’s what GrowthBook itself is built with), and we’re proud to now support even more use cases on this platform.
You can now configure any SDK Connection to sync data to Vercel Edge Config. Any time a feature flag or experiment changes in GrowthBook, we automatically update Edge Config with the latest value within seconds. This is especially powerful for server-side rendering, where latency is critical—reading from Edge Config is much faster than making a network request to GrowthBook’s servers.
We’ve also added a guide to our docs detailing how to integrate GrowthBook with the @vercel/flags library and the Vercel Toolbar for an even more seamless experience.
Azure SCIM Support
This latest release supports SCIM user provisioning for enterprises using Azure AD (also known as Microsoft Entra). You can now fully configure your users and teams within Azure, and they will be synced to GrowthBook. SSO and SCIM require a GrowthBook Enterprise license.
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