I built a tool to watch competitor A/B tests. Here's what I've learned after 30 days of live data across 1000+ brands.

Six months ago I was doing what I think most of us do: reading CRO Twitter, watching Lenny's Podcast, and making educated guesses about what to test on my landing page. At some point I got annoyed by something specific. Companies with real conversion budgets run hundreds of experiments a year and never publish what they actually found. The blog posts exist for SEO. The real learnings stay internal. So I built ABWatcher (https://www.abwatcher.com). The technical version: it crawls 1,050 brands daily, detects live A/B tests by probing vendor SDKs (Optimizely, VWO, Statsig), running same-session variant comparisons, and doing week-over-week visual diffs. When it catches something, a vision model writes up the hypothesis and the likely takeaway in plain English. No manual work on my end once it flags.

Where I am right now (full transparency):

- Launched two weeks ago
- Revenue: $0. Pre-revenue, free tier only so far
- Watching: 1000+ brands daily
- Goal this month: get 20 people on paid plans before I finalize pricing

A few patterns from the last 30 days of data that I found genuinely interesting: Pricing page tests are everywhere right now. More than half the experiments I've caught in the last 30 days touched the pricing page, mostly around plan comparison layout and what to surface on a free tier. Which is useful if you're building a SaaS and staring at your own pricing page wondering what to tweak. Above-the-fold CTAs are not where the interesting tests are happening. The action is below the fold, in objection-handling copy and where social proof gets placed. Billing toggle visibility (annual vs. monthly) is a surprisingly common test surface. I've seen at least 8 separate companies running some version of it in the last few weeks.

Free tier is 10 watched companies, permanently. Paid plans let you watch more. If you've ever wondered 'did Stripe actually test that layout?' this is basically how you'd find out. Happy to hear what companies or categories you'd want to watch. And if anyone has thoughts on where to set the paid tier pricing, I'm genuinely in that conversation right now.