Backed by Y Combinator

Every surface, every minute.

Every surface, every minute.

UI, API, CLI, and mobile tests run on a continuous cadence — you watch the green, Lark watches the red. Built by ex-Stripe engineers.

today · runs completed
12,404
99.6% pass·31 auto-repaired
ui
Checkout flow · guest
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push · main
running
api
Order webhook · paid
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schedule · 5m
running
ui
Mobile · order placed
wflw_exec_R3kQzNm9tx7
push · staging
running
cli
CLI · auth flow
wflw_exec_8mLfocK4pq2
manual · jack
running

$20 IN FREE CREDITS

$20 IN FREE CREDITS

Trusted by ENGINEERING TEAMS AT

Best-in-class testing infrastructure

Everything you need to make sure your product never breaks.

Self-healing

Tests adapt to product changes

Tests don't break when you revamp your dashboard or introduce a new API. Instead, Lark adapts and alerts you to the change.

Self-healing

Tests adapt to product changes

Tests don't break when you revamp your dashboard or introduce a new API. Instead, Lark adapts and alerts you to the change.

made for developers

Fits into the tools engineers already use

First-class support for coding agents like Claude Code, Cursor, and Codex.

made for developers

Fits into the tools engineers already use

First-class support for coding agents like Claude Code, Cursor, and Codex.

reproducible results

Useful debugging artifacts when something fails

Download reproducible test scripts, logs, screenshots, and videos.

reproducible results

Useful debugging artifacts when something fails

Download reproducible test scripts, logs, screenshots, and videos.

full coverage

Test every surface

Lark's agents can test UIs, APIs, SDKs, async workflows, and more.

FAQ

Frequently asked questions

Frequently asked questions

Everything you need to know about getting started with Lark.

Everything you need to know about getting started with Lark.

How do I integrate Lark with my CI/CD pipeline?

We provide native integrations with GitHub Actions, GitLab CI, and other popular CI tools.

What types of applications can Lark test?

Tests can be written for dashboards, API endpoints, and more. You can see some sample tests at https://tests.getlark.ai/a/polar/

How is Lark different from something like Playwright?

Playwright tests are hard to write and maintain because it's code. Lark tests are trivial to write because it's natural language. Playwright tests can be brittle and break easily if the product changes. Lark tests are more robust and can handle changes to the product. Playwright tests are for frontend only, Lark tests can be for frontend, backend APIs, and more.

What happens when a test fails in production?

You'll receive instant alerts via Slack, email, or PagerDuty with detailed logs and screenshots to help you quickly identify and resolve the issue. With our CI integration you can also prevent PRs from merging if tests fail.

Tests should write themselves. Now they do.

Tests should write themselves. Now they do.

Tests should write themselves. Now they do.