The best CRO community for most people is the Experiment Nation Slack.
It is free and built for conversion rate optimizers and product experimenters.
Add Measure Slack if you also handle analytics.
App teams should join Phiture's ASO Stack Slack too.
How we picked: we checked each community's own site or sign-up form in November 2026 to confirm it exists, how you join and what it costs.
We haven't been active members of these groups ourselves, so we don't rate how good the conversations are.
Where it helps, we point to tests in our A/B test archive that are worth bringing to a group.
CRO communities at a glance
| Name | What it is | Best for | Cost/cadence | Link |
|---|---|---|---|---|
| Experiment Nation | Slack for CROs and product experimenters | Day-to-day CRO questions | Free; ongoing chat | experimentnation.com |
| Measure Slack (#measure) | Digital analytics Slack, about 26,000 members | Tracking, analytics and test data | Free, manual approval | measure.chat |
| Women in Experimentation | Slack for women and non-binary people in experimentation | Peer support, finding speakers | Free; yearly online summit | Join form |
| CRO Coffee Club | Small-group video meetups hosted by Kameleoon | Talking live with peers | Free; first Tuesday monthly, 30 min | kameleoon.com |
| GrowthBook Slack | Open-source experimentation platform community | Engineers and data scientists | Free; ongoing chat | growthbook.io |
| Optimizely World forums | Public forums, including experimentation boards | Optimizely users | Free; ongoing | world.optimizely.com |
| Mind the Product Slack | Product management Slack, 60,000+ members | Product managers who run tests | Free; ongoing chat | mindtheproduct.com |
| Online Geniuses | Marketing Slack with a CRO channel, 53,000+ members | Marketers who do CRO part time | Vetted application; price not shown | onlinegeniuses.com |
| ASO Stack Slack | App Store Optimization Slack from Phiture, 6,000+ members | App store page tests | Free sign-up form | phiture.com |
| RevenueCat Community | Forum for subscription app developers | Paywall and pricing setup | Free; ongoing | community.revenuecat.com |
| eComFuel | Paid forum for vetted seven- and eight-figure store owners | Established ecommerce owners | $199 or $299 a month | ecommercefuel.com |
Only two of these are about CRO and nothing else: Experiment Nation and the CRO Coffee Club.
The rest are neighbors that experimenters rely on: analytics, product, app stores and ecommerce.
Most people end up in one CRO group plus one group for their kind of business.
The 11 best CRO communities
1. Experiment Nation
What it is: A community of "Conversion Rate Optimizers and Product Experimenters," with a Slack workspace, a newsletter and a podcast, according to its homepage.
Why it's worth it: It's the closest thing to a general CRO Slack.
The join form calls it a "judgement-free zone" and says invites go out within 48 hours.
Best for: CRO specialists, growth marketers and product managers who want to talk tests with people who do the same job.
Where: Fill in the Slack sign-up form. It asks for your LinkedIn profile and a few short questions about your CRO work.
Cost/cadence: Free. The Slack runs all the time, and the podcast and newsletter come out regularly.
2. Measure Slack (#measure)
What it is: A digital analytics Slack that grew out of the #measure hashtag on Twitter. Measure Chat calls it "a 26,000-strong community."
Why it's worth it: A lot of bad test results come from broken tracking, not bad ideas.
This is where people fix GA4, tag manager and data problems before a test ever starts.
Best for: Anyone who sets up test goals or reads the data, at any kind of business.
Where: Go to join.measure.chat. The form says "you must share your LinkedIn profile URL," every request is approved by hand, and you can't reapply if you've had an account before.
Cost/cadence: No fee is listed on the site or form.
Moderators are volunteers, so approval can take a while.
3. Women in Experimentation
What it is: A Slack for people in experimentation, growth and UX who "identify as female or non-binary."
The join form says it has 1,000+ people.
Why it's worth it: It's smaller and more focused than the big Slacks.
It also runs a yearly online Women in Experimentation Summit.
Best for: Women and non-binary CRO and experimentation people who want peer support, and event organizers looking for speakers.
Where: The Google Form asks for your name, email and LinkedIn profile.
Cost/cadence: The form lists no fee. The Slack runs all the time, plus the yearly summit.
4. CRO Coffee Club (Kameleoon)
What it is: "A recurring peer community for experimentation professionals" run by the testing vendor Kameleoon.
The event page promises "small group discussions" and "no presentations."
Why it's worth it: Most communities are text.
This one gets you on a call with a few peers who are working on similar problems, which is faster for messy questions like how to get buy-in for testing.
Best for: People who'd rather talk than type.
It's hosted by a vendor, so expect it to lean toward experimentation teams that might use Kameleoon.
Where: Register on the Kameleoon page. You get a monthly calendar invite, then confirm to be matched with peers and get an access code.
Cost/cadence: Free, with "no commitment." It runs for 30 minutes on the first Tuesday of every month.
5. GrowthBook Slack
What it is: The community Slack for GrowthBook, an open-source feature flagging and experimentation platform.
Its community page says "Join 5,000+ engineers, data scientists, and product managers."
Why it's worth it: The talk here is more technical than in marketing-led groups: warehouse metrics, flags and stats engines. That's useful once you outgrow visual editors.
Best for: SaaS and app teams running tests in code, and anyone already using GrowthBook.
Where: Use the "Join Slack" link on the GrowthBook community page.
Cost/cadence: Free; ongoing. It's a vendor community, so much of it is product support and release news.
6. Optimizely World forums
What it is: Optimizely's public forums, with separate Web Experimentation and Feature Experimentation boards, according to Optimizely World.
Why it's worth it: If your company runs Optimizely, other users have probably hit the same setup problem.
One downside: the page itself says the forums "are not actively managed or monitored by Optimizely employees," so use official support for urgent problems.
Best for: Developers and marketers at larger companies that use Optimizely.
Our archive has tests that ran on it, such as a homepage outfits carousel that lost (-6.07% add to cart, run by Optimizely).
Where: world.optimizely.com/forum.
Cost/cadence: Free; ongoing.
7. Mind the Product Slack
What it is: A product management Slack. Its sign-up page says "Join 60,000+ product people."
Why it's worth it: In SaaS, product managers often decide what gets tested.
Channels like #advice and #feedback are good places to get feedback on onboarding or pricing ideas from people outside CRO.
Best for: SaaS and app product managers. It has no channel just for experimentation, so pure CRO specialists will find less here.
Where: Request an invite by email on the Mind the Product Slack page.
Cost/cadence: The page lists no fee; ongoing chat.
8. Online Geniuses
What it is: "A SEO & Digital Marketing Community based on Slack" with "53,000+ manually vetted members" and a Conversion Rate Optimization channel, according to its homepage.
Why it's worth it: It's a large audience of marketers who do CRO as part of a wider job.
That makes it useful for questions about landing pages, paid traffic and lead gen.
Best for: Generalist marketers, agency staff and lead-gen site owners.
The broad focus means CRO threads compete with SEO and ads talk.
Where: Apply through the membership portal.
Cost/cadence: Membership is vetted and the site also sells a "Pro" tier.
We couldn't find prices on the public pages, so check before you apply.
9. ASO Stack Slack (Phiture)
What it is: A Slack for App Store Optimization people run by the mobile growth agency Phiture.
Its sign-up page says it has "6,000+ active members."
Phiture also lists a separate Mobile Growth Stack Slack on its ASO Stack page.
Why it's worth it: Store page tests (icons, screenshots, custom product pages) have their own tools and quirks.
Web CRO groups rarely cover them. Read our ASO guide before you post.
Best for: Mobile app marketers and ASO specialists.
Where: The registration form on Phiture's page asks for a professional email address.
Cost/cadence: No fee is listed; ongoing chat.
10. RevenueCat Community
What it is: A public forum for subscription app developers.
When we checked, it showed 9,363 members and 6,394 posts, with boards for SDKs, dashboard and tools, integrations and general questions.
Why it's worth it: Paywall and pricing tests often stall on setup: products, offerings, receipts.
This is where those problems get solved. The paywall ideas themselves you can study in our paywall guide.
One example: Slopes tested a one-tap trial card instead of the paywall and got +25% trial starts, with trial-to-paid about the same (Slopes).
Best for: Subscription app developers, especially those on RevenueCat.
Where: Sign up with an email or your RevenueCat account at community.revenuecat.com.
Cost/cadence: Free; ongoing. It's more about the developer side than strategy.
11. eComFuel
What it is: "A private community of 1,000+ vetted owners running seven- and eight-figure stores," per its homepage.
It includes a forum archive, a member directory, events and "15,000 member-written reviews of software, agencies and vendors."
Why it's worth it: Owners compare real results from testing apps, agencies and offers, without vendors in the room.
The software and agency reviews alone can save you a bad hire.
Best for: Established ecommerce owners. It's not for beginners, freelancers or SaaS teams, because members have to meet a revenue bar.
Where: Apply on ecommercefuel.com.
Cost/cadence: $199 a month for the 7-Figure plan and $299 a month for 8-Figure+, as listed in November 2026.
Which community fits you
You work in CRO full time
Join Experiment Nation and add the CRO Coffee Club if you like live calls.
If you're early in your career, our CRO specialist guide covers the skills these groups expect you to have.
You run tests at a SaaS company
Mind the Product for product questions, GrowthBook Slack if your tests run in code.
You run a mobile app
ASO Stack Slack for store page tests and the RevenueCat Community for paywall setup.
You own an ecommerce business
eComFuel if you meet the revenue bar. If you don't, Experiment Nation and Measure Slack are free and cover most testing and tracking questions.
You're a marketer who does a bit of everything
Online Geniuses for its CRO channel, plus Measure Slack for data questions.
How to get the most from them
- Share the setup, not just the headline. Post the traffic, test length, main metric and the tool. Without them, nobody can tell you if a result is real. Our statistical significance guide explains what people will ask.
- Bring losses and flat tests. These get the most useful replies. In our archive, GrowthRock's "You Save #%" price label made no change in conversion, and Booking.com moving registration steps higher brought no lift.
- Ask about results that don't add up. AssessmentDay found that removing the FAQ section gave +62% sales and removing screenshots gave +56%, but removing both lost (-3% sales). Results like that are what these groups are good at picking apart. See our guide to interaction effects.
- Read the rules before you post links. Measure Slack's form bans product promotion and spam, and most groups have similar rules.
- Write down what you learn. Keep a learning repository so advice from a thread turns into your next test.
- Add slower sources. Chat moves fast. For deeper reading, see our lists of CRO newsletters, CRO podcasts, CRO conferences and CRO books.
Real results worth discussing
These tests from our archive include wins, losses and flat results.
They make good starting points for a thread.
Optimizely
GrowthRockWatch out for
- Vendor-run groups. Kameleoon, GrowthBook, Optimizely and RevenueCat host four of these. They're useful, but expect the conversation to center on their product.
- Winners with no details. A "+40%" with no traffic or test length is a story, not evidence. Ask for the numbers before you copy it.
- Copying tactics across business types. What works for a store's product page may not work on a SaaS pricing page or an app paywall. Test it on your own traffic.
- DM pitches. Big open Slacks attract people selling services. Check anyone's public case studies before you hire them.
If you'd rather have someone run your testing program than ask a forum, a practitioner can help.
Oliver Kenyon has spent 13 years in ecommerce CRO.