We've built an AI testing agent that lets anyone on your team—engineers, PMs, and QA—create and maintain tests without writing code.
❌ The Problem / ✅ Our Value
Stop shipping bugs. Stop waiting for tests. Stop fixing broken test suites.
Stably is an AI QA engineer that understands your product, tests intelligently, and integrates seamlessly into your workflow. https://youtu.be/p-cjcxjTH-E
💪 Our 3 Core Strengths
1. ⚡ Speed: 10x Faster Testing
Smart test selection: Our AI analyzes PR diffs and runs only affected tests—when you change checkout, we test checkout, not your entire suite
Automated test creation: Tests that once took hours of hand-coding in Playwright or Cypress now generate automatically in under 10 minutes.
Intelligent caching: Tests run in cached Playwright until your app changes, then auto-heal
2. 🎯 Accuracy: AI That Actually Understands Your Product
99.7% assertion accuracy by learning from your Notion docs, Google Drive specs, PostHog recordings, and Git history
Context-aware testing: Tell Stably "test checkout with expired coupons" in plain English—it knows what checkout means in YOUR app
Catches real bugs: Not just UI changes, but actual business logic failures
3. 🧩 Easy Integration: Works for Everyone, Everywhere
No-code for all teams: PMs describe tests in English, QAs point-and-click to show flows, and engineers get PR-ready tests
One-click GitHub app or use our API for GitLab, local CLI, and Cursor MCP (upcoming)
Human-in-the-loop: When AI needs help, anyone can step in and show it what to do—no coding required
💥 Real Impact
OpenArt scaled from $0 to $16M ARR with just 10 employees using Stably
Tofu saves 40+ engineering hours per week after migrating from Playwright
"I actually love testing now after switching to Stably" — Senior Engineer, Curebase (YC W18)
👩🏻💻🧑💻 About Us
Jinjing (CEO): Built the testing & release infrastructure that ships Google Chrome to billions of users
Neil (CTO): One of Uber's youngest Tech Leads; led multiple large-scale ML projects on Uber's Safety team
We've assembled a team of PhD graduates specializing in AI’s application in software reliability, plus ex-founders who've previously built and sold an AI startup.
🎉 Launch Week Special
We're looking for teams who:
Wait too long for PR tests to run
Have PMs/QAs who want to contribute to testing but can't code
Are tired of updating tests every time they ship
Get the first month free on our starter plan. Just mention "YC Launch" when signing up.