Built for Chrome & Edge Manifest V3 extensions

Catch critical extension regressions before you publish — without building a test framework.

Load your extension, record the journeys that matter, then replay them locally across host pages, popups, content scripts, service workers, and storage.

Concept validation only. Nothing is available to download, and you will not be charged.

Local by default
MV3-aware diagnostics
Readable Playwright export

Interactive concept — not a released product

BUILD INSPECTED

Five MV3 surfaces detected

Planned analysis of an unpacked local build. No source upload.

The problem

Extension testing isn’t ordinary web testing.

MV3 extensions span browser-only surfaces and an event-driven lifecycle. Teams often fall back to manual release checklists or maintain custom Playwright and Puppeteer fixtures for popup, content-script, worker, and storage behavior.

Planned workflow

Protect the few journeys a release cannot afford to break.

This concept is deliberately narrow. It would automate repeatable regression checks, not replace exploratory QA.

Load your build

Select an unpacked extension folder or local ZIP. The proposed local workflow would not upload source code.

Record critical journeys

Capture clicks, inputs, and simple checks across host pages, popups, and extension UI.

Replay in a clean profile

Run locally with synthetic test data and block payments or destructive actions by default.

Debug the first divergence

Review the failing step, visual evidence, consoles, network activity, and worker state.

The proposed middle ground

Less maintenance than a custom framework. More control than a closed recorder.

Extension-aware

Designed around MV3 surfaces and lifecycle instead of treating the extension like a normal website.

Local by default

The proposed runner keeps extension code, test data, and secrets on your machine during local runs.

No test lock-in

Planned readable Playwright/crxbox export gives your team a path out of the visual interface.

Free MV3 testing resources

Useful even if MV3 Replay never becomes a product.

Start with concrete release checks, a Playwright setup, and service-worker failure cases. No account or email is required.

Release safety

Manifest V3 testing checklist

Cover the popup, content UI, permissions, storage, upgrades, and destructive-action safeguards before publishing.

Automation

Test a Chrome extension with Playwright

Load an unpacked build, discover its ID, open extension pages, and keep the end-to-end layer focused.

Lifecycle

Test an MV3 service worker restart

Expose assumptions about global state, listener registration, alarms, and cold-start behavior.

Browse all testing guides

A fair objection

“Why not ask an AI coding agent to write the tests?”

That may be enough for some teams. This concept is for teams that would pay for a repeatable visual workflow, extension-specific diagnostics, and an export they still own. This validation is intended to discover whether enough such teams exist.

FAQ

Clear boundaries before you choose.

What would be supported first?

Chromium-based Chrome and Edge, Manifest V3, unpacked folders or local ZIPs; popup, options page, content scripts, service worker, and chrome.storage.

Would it catch every bug?

No. The concept targets repeatable regression checks. It is not a security audit, compliance product, store-approval service, or replacement for exploratory QA.

Would you upload my extension?

The proposed local workflow would not upload extension source code or secrets. Only limited account and billing data would be retained if a product launches.

What about Firefox, Safari, and mobile?

They are outside the proposed initial scope.

Does this guarantee Chrome Web Store approval?

No.

Help test the premise