Checks manifest.json against Manifest V3 and Chrome Web Store upload rules: MV2 leftovers, host patterns in permissions, remote code, field limits. Runs entirely in your browser — nothing is uploaded.
Same engine as the VS Code extension, byte for byte.
This page is the working piece. The full pack has everything below.
25 rules over manifest.json: every line Manifest V3 or the Chrome Web Store upload refuses, with the fix beside it. The shipped MV2 fixture returns 19 findings, 16 of them errors that block
A contract extension developer at $80/h costs more than the licence after 22 minutes of resubmission rework, and a rejected upload restarts the Chrome Web Store review queue.
Buy the full version — $29It reads a manifest.json and returns every line Manifest V3 or the Chrome Web Store upload will refuse, with the replacement beside it. 25 rules cover MV2 leftovers such as browser_action and background.scripts, policy blockers such as remotely hosted code and webRequestBlocking, and upload fields such as version format, the 75-character name limit and the missing 128px icon.
Chrome and Edge extension developers who are about to upload, and teams whose manifest was drafted or refactored by a code assistant trained on Manifest V2 examples. It is equally useful for an agency migrating a client's old MV2 extension, where the manifest is the first thing the Chrome Web Store reviewer's pipeline rejects.
Chrome tells you at upload time, one review cycle per attempt, and stops you at the error it hits. Mozilla's web-ext lint checks Firefox AMO rules, not the Chrome Web Store's field limits, remote-code policy or permission split. This runs all 25 Chrome rules in your editor before the ZIP is built.
Free covers the file you have open: every rule, every finding named, nothing hidden. The licence adds a different job - scanning every manifest.json in the workspace in one run and exporting the result as a Markdown and JSON report you keep for CI and for your reviewer.
Reading the current manifest reference and store policies against one file takes a developer a sitting, and each miss costs another review cycle. At an $80/h contract rate, 22 minutes of resubmission rework already exceeds the $29 licence. The free tier costs nothing and finishes one file.
One question, answered by the person who built it. Your email only if you want the answer sent.