Growthbook Release Notes

GrowthBook version 4.1 includes Holdouts, Dashboards, AI features, and More!

This release continues the momentum of GrowthBook 4.0 by adding two of our most requested Enterprise features - Holdouts and Experiment Dashboards. Plus, we’ve made several significant enhancements to our integrations with AI coding tools and our MCP server capabilities. If you’re not yet using GrowthBook with your AI coding tools, we highly recommend it!

Read on to learn more about these features and everything else we’ve been working on these past 2 months.

Holdouts

Holdout experiments measure the long-term impact of features by maintaining a control group that doesn't receive new functionality. While most users experience your latest features and improvements, a small percentage remains on the original version, providing a baseline to measure cumulative effects over time. Read more about holdouts.

Experiment Dashboards

Experiment Dashboards let you create tailored views of an experiment. Highlight key insights, add context, and share a clear story with your team. For example, highlight the key goal metric results, show an interesting dimension breakdown, and link to supporting external documents, all in a single view. Dashboards are available for all Enterprise customers. We have a lot planned for this in the future, so stay tuned!

AI Features

This release deeply integrates AI to help accelerate your workflows within GrowthBook. Auto-summarize experiment results, get help writing SQL, improve hypotheses, detect similar past experiments, and more. These features are available even if you’re self-hosted, just supply an OpenAI API key. See the AI features in action or read detailed information on how these features work.

MCP Updates

We've updated our MCP Server to allow creating experiments directly from your AI coding tool of choice without needing to context switch to GrowthBook. This change unlocks a bunch of new, exciting workflows, and we can't wait to see how you use it!

Vercel Native Integration

We're excited to announce that GrowthBook is now available as a native integration in the Experimentation category on the Vercel Marketplace! This integration makes it easier than ever to add feature flagging and A/B testing to your Vercel projects, with streamlined setup, unified billing, and ultra-low latency performance. Read more on our announcement post.

Pre-computed Dimensions

You can now pick a set of key experiment dimensions and pre-compute them along with the main experiment results. This allows for more efficient database queries and instant dimension breakdowns in the UI. Read more in our docs.

FerretDB Support

FerretDB is a MongoDB-compatible database that is open source and free to use. It serves as a drop-in replacement for MongoDB, converting MongoDB wire protocol queries to SQL and using PostgreSQL as its backend storage engine. We're pleased to support FerretDB officially!

Sanity CMS Integration

Sanity is a real-time content backend for all your text and assets. You can now use GrowthBook feature flags to seamlessly test different content variations within Sanity. Check out our announcement video and tutorial or our docs.

The 4.1 release includes over 150 commits, way more than we can quickly summarize here. View the release details on GitHub for a more comprehensive list. As always, we love feedback - good and bad. Let us know what you think of the new features and what you want to see as part of 4.2!

Release Highlights

Holdouts

Holdout experiments measure the long-term impact of features by maintaining a control group that doesn't receive new functionality. While most users experience your latest features and improvements, a small percentage remains on the original version, providing a baseline to measure cumulative effects over time.

Experiment Dashboards

Experiment Dashboards let you create tailored views of an experiment. Highlight key insights, add context, and share a clear story with your team. Dashboards are available for all Enterprise customers. We have a lot planned for this in the future, so stay tuned!

Vercel Native Integration

We're excited to announce that GrowthBook is now available as a native integration in the Experimentation category on the Vercel Marketplace! This integration makes it easier than ever to add feature flagging and A/B testing to your Vercel projects, with streamlined setup, unified billing, and ultra-low latency performance.

AI Features

This release deeply integrates AI to help accelerate your workflows within GrowthBook. Auto-summarize experiment results, get help writing SQL, improve hypotheses, and detect similar past experiments, and more. These features are available to everyone, even self-hosted (just supply an OpenAI key).

Pre-computed Dimensions

You can now pick a set of key experiment dimensions and pre-compute them along with the main experiment results. This allows for more efficient database queries, and instant dimension breakdowns in the UI.

FerretDB Support

FerretDB is a MongoDB-compatible database that is open source and free to use. It serves as a drop-in replacement for MongoDB, converting MongoDB wire protocol queries to SQL and using PostgreSQL as its backend storage engine.

Sanity CMS Integration

Sanity is a real-time content backend for all your text and assets. You can now use GrowthBook feature flags to seamlessly test different content variations within Sanity.

MCP Updates

We've updated our MCP Server to allow creating experiments directly from your AI tool of choice without needing to context switch to GrowthBook. This change unlocks a bunch of new exciting workflows and we can't wait to see how you use it!

New Experiment Results Tooltip

We've completely redesigned the tooltip when mousing over experiment results. The new design provides more context and insights at a glance, making it easier to understand the impact of your experiments.

SQL Auto-Complete

We've added context-aware SQL auto-complete suggestions for table and column names to help you write queries faster and with fewer errors.

Official Segments and Dimensions

You can now mark specific segments and user dimensions as Official via the GrowthBook API. This will give them a little badge in the UI and lock down editing to prevent unwanted changes. Use this to differentiate important segments and dimensions from ad-hoc or exploratory ones.

Self-Hosting Improvements

For anyone self-hosting GrowthBook, we've greatly improved observability and customization. We now support full monitoring and tracing of all background jobs, plus distributed tracing within the Python stats engine. We also added a number of new env vars to more easily split the GrowthBook monolith into microservices for those that need extra scalability.

SDK Updates

• React - Full React 19 Typescript support
• Golang - SSE streaming fixes
• PHP - sticky bucketing fixes
• Java - new caching and refresh options, memory optimizations
• Flutter - many bug fixes and updates
• C sharp - SSE streaming, attribute targeting fixes
• Swift - sticky bucket fixes, support for bearer auth, logging improvements, and memory optimization
• Kotlin - async-safe sticky bucketing, new streamingHost setting, suspend entry points to avoid blocking
• Flutter - TTL-based fetch option, cache improvements, attribute targeting fixes
• Edge - many new options for advanced integrations

REST API Updates

• New GET /settings endpoint to fetch all of your organization's current settings
• Fix PUT /metric/:id endpoint that was ignoring the archived setting
• New GET /feature/:id/revisions endpoint to fetch all revisions for a specific feature with pagination
• New endpoints to create, update, and delete dimensions and segments
• Ability to archive fact tables and fact metrics Plus a lot more
• New is:watched filter on experiment search
• Enable encryption option for back-end SDKs
• Add user-agent header to all HTTP requests (webhooks, etc.)
• Various date and timezone fixes
• Various SQL editing and schema browser fixes
• Properly close MySQL connections
• Ability to remove LIMIT 5 when testing SQL queries
• Use Webhook Secrets by default for new webhooks
• ClickHouse - add support for new JSON data types
• Wrap user-supplied SQL in parentheses to avoid edge cases
• Fix divide-by-zero bug in stats engine
• Jira integration update to support a custom field
• Fix stale feature detection logic
• New Big Number visualization type in the SQL Explorer
• Enable the schema browser for self-hosted orgs that use config.yml
• Improve fact metric query performance by filtering rows earlier
• Fix broken SRM check when one variation has 0 users
• Fix bugs with quantile and percentile capped metric settings
• Audit log entries now show the full date time instead of "X days ago"
• Power calculator fixes
• Allow manual seed selection for feature rollout rules
• Skip feature.updated webhooks until draft changes are actually published
• Improve handling of unit quantiles when "ignore zero" is set
• Persist last viewed tab on the experiment list

New Contributors

• @nodirnasirov made their first contribution in #4296
• @kweic made their first contribution in #4315
• @denisov-vlad made their first contribution in #4351
• @Khrol made their first contribution in #4339
• @benruehl made their first contribution in #4254

Plus a ton of returning contributors: @jdorn @royalfig @tzjames @ahdriel @mknowlton89 @madhuchavva @bryce-fitzsimons @natasha-growthbook @Auz @lukesonnet @Kevin-Chant @lukebrawleysmith @Hephaest @gazzdingo @ari-party @msamper @itsgrimetime

Full Changelog: v4.0.0...v4.1.0

GrowthBook 4.0 includes a huge number of new features and updates. Continue reading for a full list of changes.

We shipped so many new features in our June Launch Month that we decided that it deserved a major version increase. Version 4.0 brings a huge array of new features. Here’s a quick summary of everything it includes.

GrowthBook MCP Server

AI tools like Cursor can now interact with GrowthBook via our new MCP server. Create feature flags, check the status of running experiments, clean up stale code, and more.

Safer Rollouts

Building upon our Safe Rollouts release last version, we added gradual traffic ramp up, auto rollback, a smart update schedule, and a time series view of results. All of these combine to add even more safety around your feature releases.

Decision Criteria

You can now customize the shipping recommendation logic for experiments. Choose from a “Clear Signals” model, a “Do No Harm” model, or define your own from scratch.

Search Filters

We’ve revamped the search experience within GrowthBook to make it easier to find feature flags, metrics, and experiments. Easily filter by project, owner, tag, type, and more.

Insights Section

We added a brand new left nav section called “Insights” with a bunch of tools to help you learn from your past experiments.

• The Dashboard shows velocity, win rate, and scaled metric impact by project.
• Learnings is a searchable knowledge base of all of your completed experiments.
• The Experiment Timeline shows when experiments were running and how they overlapped with each other.
• Metric Effects lists the experiments that had the biggest impact on a specific metric.
• Metric Correlations let you see how two metrics move in relation to each other.

SQL Explorer

We launched a lightweight SQL console and BI tool to explore and visualize your data directly within GrowthBook, without needing to switch to another platform like Looker.

Managed Warehouse

GrowthBook Cloud now offers a fully managed ClickHouse database that is deeply integrated with the product. It’s the fastest way to start collecting data and running experiments on GrowthBook. You still get raw SQL access and all the benefits of a warehouse native product, without the setup and maintenance cost.

Feature Flag Usage

See analytics about how your feature flags are being evaluated in your app in real time. This is built on top of the new Managed Warehouse on GrowthBook Cloud and is a game changer for debugging and QA.

Vercel Flags SDK

GrowthBook now has an official provider for the Vercel Flags SDK. This is now the easiest way to add server-side feature flags to any Next.js project. We have an even deeper Vercel integration coming soon to make this experience even more seamless.

Official Framer Plugin

You can now easily run GrowthBook experiments inside of your Framer projects. Assign visitors to different versions of your design (like layouts, headlines, or calls to action), track results, and confidently choose the best experience for your audience.

Personalized Landing Page

There’s a new landing page when you first log into GrowthBook. Quickly see any features or experiments that need your attention, pick up where you left off, and learn about advanced GrowthBook functionality to get the most out of the platform.

New Experimentation Left Nav

There’s a new “Experimentation” section in the left nav. Experiments and Bandits now live within this section, along with our Power Calculator, Experiment Templates, and Namespaces. We’ll be expanding this section soon with Holdouts and more, so stay tuned!

REST API Updates

• Filter the listFeatures endpoint by clientKey
• Support partial rule updates in the putFeature endpoint
• New Queries endpoint to retrieve raw SQL queries and results from an experiment
• Added Custom Field support to feature and experiment endpoints
• New endpoints for getting feature code refs
• New endpoint to revert a feature to a specific revision

Performance Improvements

We’ve drastically improved the CPU and memory usage when self-hosting GrowthBook at scale. On GrowthBook Cloud, we’ve seen a roughly 50% reduction during peak load, leading to lower latency and virtually eliminating container failures in production.

Managed Warehouse

This week we're launching our Managed Warehouse and Feature Flag Usage Analytics.

Launch month continues with our Managed Warehouse product and feature flag usage analytics.

We’ve talked to thousands of companies and have seen our fair share of data warehouse and event tracking setups. We’ve noticed 3 consistent problems:

• 1. They are a LOT of work to set up and maintain, especially for companies without dedicated data engineers. Google Analytics + BigQuery is the most common one we see and that takes over 40 steps to configure (yes, we counted).
• 1. Data is often refreshed on a schedule instead of in real-time. You don’t want to wait 24 hours to find out a new feature or experiment is killing your metrics.
• 1. Pricing and performance are optimized for batch workloads. Refreshing experiment results frequently or exploring your data can become slow and costly.

This week, we’re excited to launch our new Managed Warehouse product on GrowthBook Cloud. We set out to solve all of these issues and we’re super happy with the results:

• 1. One-click setup and zero maintenance. Doesn’t get much easier than that!
• 1. Data arrives within seconds, letting you quickly detect issues.
• 1. Queries are crazy fast and free (only pay for ingesting the data, not querying it)

Under the hood, this is powered by ClickHouse, an open source database optimized for fast analytics at scale. You still get raw SQL access and all the other benefits of a true Warehouse Native platform, just without the cost. The first 2 million tracked events each month are free for Pro users and we have super affordable usage-based pricing beyond that.

Feature Usage Analytics

This week we’re also launching Feature Usage Analytics, which was built to take advantage of many of the benefits of the new Managed Warehouse. For each feature flag, you can see how often it's been evaluated, which values are being served, which rules are being hit, and more. This is a game changer for feature flag management and makes debugging issues so much faster. As an extra benefit, this also helps you stay on top of tech debt by highlighting stale flags that are no longer being used. So how does it work? The GrowthBook SDK sends an event to the Managed Warehouse every time a feature flag is evaluated in your app. This usage data is then aggregated and displayed within seconds. For now, this is only available for the new Managed Warehouse on GrowthBook Cloud, but we want to eventually open this up to everyone. If you are interested in this, but are self-hosting (or already have a data warehouse), let us know and we can keep you in the loop!

For week 3 of our Launch Month, we're releasing SQL Explorer, which lets you query your data and visualize results.

For week 3 of our Launch Month, we’re excited to announce the SQL Explorer!

At GrowthBook, we love dogfooding our product (most of our launches this month started behind feature flags). Along the way, we kept running into a common frustration: answering simple data questions meant jumping into separate tools like Looker, Mode, or Tableau - just to write some quick SQL or generate a basic chart.

All of that context switching adds up, which is why we built SQL Explorer - a lightweight, built-in SQL editor that lets you query your data, create visualizations, and save results right inside of GrowthBook. It's perfect for quick analyses without the overhead of a full BI platform. Check it out and let us know what you think.

We’ll be adding more features and integrating the SQL Explorer more deeply in the product in the coming weeks, so keep an eye out!

This week we're launching Insights, which includes a new Executive Dashboard, searchable experiment learnings, timeline visualizations, and deep metric analysis.

This week is all about Insights, the brand new section in our sidebar. In there, you’ll find a revamped Executive Dashboard, new Learnings and Timeline pages, plus some powerful metric analyses to help you get the most out of your experimentation program. This section becomes more useful the more experiments you run, so if you needed an excuse to run more tests this is it!

Executive Dashboard

The brand new dashboard gives you a 10,000 foot view of your organization’s experimentation program. Quickly see your team’s velocity, win rate, and impact. Enterprise users can also select a metric and see the cumulative effect from all the experiments that were run. Everything can be filtered by project and date range.

Learnings

The Learnings page is a searchable knowledge base of every experiment your team has completed. For each experiment, see the winning variation, a summary of results, and other key details. This page is a great place for new team members to learn about what has been tried and what has and hasn’t worked.

Fun fact: This was the original reason we started GrowthBook and how we got our name. We envisioned a digital book of everything you’ve learned about growth.

Experiment Timeline

The Timeline page lets you visualize when experiments were running in relation to each other. Experiments are color-coded by status (running, won, lost, etc.) and split up by phases. This is a valuable tool for managing your experimentation workflow, identifying bottlenecks in your process, and planning future tests.

Metric Effects

Do a deep-dive for a given metric and see the range of effect sizes from all the experiments that included it. Use this to learn how easy/hard it is to move your metric in general and see which specific experiments had the biggest impact (both good and bad).

Metric Correlations

See how any 2 metrics tend to move in relation to each other within experiments. This is especially useful for identifying proxy metrics that are highly correlated with your long term goals, but can get you results much faster.

We hope you find these new pages useful and we look forward to hearing your feedback. See you again soon for our Week 3 launches!

This June is our Launch Month! Every week, we’ll announce major new features and changes to GrowthBook that you can try out early, before the final release at the end of the month.

We have so many exciting projects we’re working on, we decided to do something a little different for this next release. June will be our official Launch Month! Every week we’ll announce major new features and changes to GrowthBook that you can try out early, before the final release at the end of the month.

Let’s kick things off with the Week 1 launches:

GrowthBook MCP Server

We launched the first ever MCP server for feature flagging and experimentation! MCP (Model Context Protocol) allows AI tools to communicate and do actions directly with services like GrowthBook. Now you can use AI to create feature flags, check experiment results, clean up stale code, and more, directly within your IDE. Read our announcement blog post for more info and a demo.

Even Safer Rollouts

We made three big changes to Safe Rollouts to make them even safer:

• 1. Traffic now gradually ramps up from 10% to 100%
• 1. Results are checked more frequently at the start of a Safe Rollout (and less frequently the longer it’s running)
• 1. There’s a new setting to automatically roll back if any guardrails are failing or the data looks unhealthy

When combined, these changes help make your rollouts even safer by minimizing the user impact when things go wrong. As always, you can learn more about this in our docs.

Custom Decision Criteria

You can now customize the logic that powers our Experiment Decision Framework on a per-experiment basis.

• Clear Signals (the default) - Ship only with clear goal metric successes and no guardrail failures.
• Do No Harm - Ship so long as no guardrails and no goal metrics are failing. Useful if the costs of shipping are very low.
• Custom - Define your own fully custom decision criteria logic using our intuitive UI.

Check out our docs for more information.

Search Filters

We’ve revamped the search experience within GrowthBook to make it easier to find feature flags and metrics. Easily filter by project, owner, tag, type, and more. The best part is that all of your filters are encoded in the URL, so once you find a view you like you can easily get back to it or share it with your team. We’ll be rolling this out to other parts of the app soon.

This release includes an exciting new feature flag rule, a long-awaited addition to experiment results, an integration sure to make PMs happy, and a lot more! Keep reading for details.

Safe Rollouts

Introducing our newest type of feature flag rule—Safe Rollouts!

Safe Rollouts let you gradually release a feature while monitoring guardrail metrics for regressions. It’s designed to be simple to use, so there’s no reason not to wrap it around every bit of code you release. In fact, we used Safe Rollouts to release Safe Rollouts in GrowthBook Cloud just this week. So meta!

Under the hood, Safe Rollouts uses sequential testing and one-sided confidence intervals to continuously monitor guardrail metrics and quickly detect harmful changes, without inflating the false positive rate.

We couldn’t wait to get this into your hands and hear your feedback, so this initial release is intentionally minimal. Don’t worry though, we have a lot planned for the near future: automated ramp ups (10% → 25% → 50% → 100%), time series view of results, deep dives, and more. Stay tuned!

Time Series

We’ve added one of our most requested features to experiment results: a Time Series view for metrics! Now you can expand any metric and see how it has changed throughout the lifetime of the experiment. The best part? We were able to add this without any additional (and expensive) SQL queries against your data warehouse, so it all comes for free.

Official Jira Integration

We just launched our first official Jira integration! You can now install the GrowthBook app from the Atlassian Marketplace and easily link a feature or experiment to any Jira issue. See key details and up-to-date statuses directly in Jira without needing to switch contexts.

Check out the Jira Integration docs to learn more and get started.

Decision Framework Events and API

In the previous release, we launched the Experiment Decision Framework to give you recommendations in the UI about when an experiment is ready to stop and what decision you should make (ship or rollback). In this release, we extended this info to both the REST API and Webhooks. That means you can get an alert in Slack whenever an experiment is ready to call or build your own custom workflows around these events.

Dev Tools for SSR

Our GrowthBook Dev Tools browser extension has always been a great way to debug and QA feature flags, but it was limited to client-side applications only. We’re excited to finally bring the same developer experience to the back-end, starting with Server-Side Rendered (SSR) Javascript applications. All it requires is a few small changes to your back-end GrowthBook implementation.

So how does it work? When you override a feature flag, experiment, or attribute in Dev Tools, we persist it in a cookie. This is sent to the back-end and applied locally before processing the request. Then, debug logs from the back-end SDK are injected into the rendered HTML and picked up by Dev Tools.

Fact Table JSON Columns

It’s common to have a single shared “Events” table in your data warehouse where everything from page views to purchases are logged together. While a JSON blob column is a convenient way to store meta info about each event, it also makes it harder to query and use as part of metric definitions.

Fact Tables in GrowthBook now have native support for JSON columns. When creating metrics, you can easily reference nested fields in row filters and even use them as metric values. No more writing custom SQL filters and trying to remember the syntax.

Fun fact: Every single database engine decided to come up with their own syntax for querying JSON data, so we had to reimplement this feature 10+ different times.

👉 Find the full release notes on GitHub.

GrowthBook 3.5

GrowthBook 3.5 enhances user experience with a revamped Dev Tools extension, a data-driven Power Calculator, an Experiment Decision Framework, and comprehensive SDK updates.

With this release, we focused on user experience and productivity improvements. There’s a completely revamped Dev Tools browser extension, a Power Calculator, an experiment Decision Framework, and tons of UI and SDK improvements. Read on for more details.

Dev Tools Browser Extension

Dev Tools Browser Extension: Experience a complete design overhaul with new features, including Firefox support and dark mode.

Our Chrome Dev Tools extension has been an essential tool for debugging feature flags and experiments since 2022, but we knew it could do even more. That’s why we completely rebuilt it from the ground up, making it faster, more powerful, and a lot more pleasant to use. There are too many improvements to list them all, but here are some highlights:

• Firefox support!
• Complete design overhaul (including dark mode!)
• Event logs and SDK health checks
• Sync Archetypes from GrowthBook to quickly simulate different users
• New popup entrypoint (just click the GrowthBook extension icon)

Download for Chrome or Download for Firefox to get started or check out the docs to learn more.

Power Calculator

Power Calculator: Accurately estimate experiment run times and minimum detectable effects using your historical data.

Many existing A/B test calculators estimate required sample sizes for statistical power but lack access to your historical data and specific metric definitions, limiting their accuracy. Recognizing this gap, we've developed our new built-in Power Calculator to provide more precise and tailored estimates.

This tool operates in two straightforward steps:

• Define Your Audience: Specify which users will be exposed to your experiment by selecting a past similar experiment, choosing a segment, or building an audience from a fact table.
• Set Your Goal Metrics: Identify the metrics that matter most to your experiment's success.

Once these steps are completed, the Power Calculator performs quick queries against your data warehouse, providing you with the estimated run time and minimum detectable effect (MDE) based on your historical data.

You can access the Power Calculator from the top of the Experiments page. Leveraging historical data requires a Pro or Enterprise license; however, a manual version is available for free accounts. For detailed instructions and a deeper statistical understanding, please refer to our documentation.

Experiment Decision Framework

It can be hard to know when to stop an experiment and make a decision. To help with this, we’re launching the first version of our Experiment Decision Framework. When enabled, running experiments will now show some additional info:

• Unhealthy - if there are data quality issues or the test is too low-powered
• No data - if the test has been running for 24 hours and there’s no data yet
• ~X days left - how long until the test reaches the desired statistical power
• Ship now - if all goal metrics are positive and statistically significant
• Roll back now - if all goal metrics are negative and statistically significant
• Ready for review - if the test has run for long enough, but there is no clear winner

For now, you must manually enable the Decision Framework under General Settings to get these new statuses. This feature is available to all Pro and Enterprise customers. We are continuing to improve this feature and are looking for feedback, so let us know your thoughts!

Read the docs for more info.

SDK Updates

SDK Updates: Our SDKs now support pre-requisite features and sticky bucketing across multiple platforms.

Some of our SDKs have fallen a little behind, so we’ve been working hard to bring them all up to spec.

Pre-requisite Features and Sticky Bucketing are now supported in the latest versions of all of the following SDKs:

• JavaScript (including Node, React, and Edge)
• Swift (iOS)
• Kotlin (Android)
• Flutter
• Java
• C#
• Python
• Ruby
• Go (sticky bucketing coming soon)

Open Feature is now supported for Web (Javascript, React), Node.js, Java, and Python.

We’ve also released dozens of bug fixes, performance improvements, enhanced thread safety, and more across many of our SDKs. Check out the individual release notes for more info.

We’re continuing to invest more time in all of our SDKs going forward to make sure every language and framework has a top-notch developer experience. If you find something that can be improved, please let us know!

Design System Updates

Last but not least, our design system migration is moving along quickly. You should notice big improvements to dark mode, feature and experiment pages, and more consistency and UI polish in general across the entire app. Let us know if you have any feedback!

To explore all the changes in this release, please visit our release notes.

GrowthBook 3.4 is live! Streamline experimentation and automate workflows with Experiment Templates, Custom Fields, Shareable Experiments & more.

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 every PR and clean it up automatically 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 and 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 re-usable “Archetype” is only available to Enterprise.