About fixjson.dev

Why this site exists

fixjson.dev started as a practical answer to a recurring developer annoyance: almost-valid JSON that fails in production parsers. Model-generated payloads, casually edited configs, and copy-paste from chats regularly include syntax that humans forgive and machines reject.

The goal is not to invent a new data format. The goal is to help you recover strict JSON quickly, understand what went wrong, and optionally check structure with a schema—without installing a desktop app or pasting secrets into an opaque remote API.

How the workshop works

The fixer runs entirely in the browser. You paste input, choose Fix JSON (or press Cmd/Ctrl+Enter), and review repaired output plus applied fix notes. Optional schema validation compares the fixed document against structure rules you provide.

Companion guides explain the failure modes behind the tool: LLM JSON mistakes, trailing commas, JSON versus JSON5/JSONC, and schema validation. Those articles are written for humans and for crawlers reviewing publisher quality—not as thin stubs around an empty calculator page.

Privacy and ownership

We design the product around local processing. Repair logic does not require uploading your JSON to fixjson.dev servers. Convenience features such as recent-history use browser storage on your device.

Contact: support@fixjson.dev. For policy details, see the Privacy Policy and Terms linked in the site footer.

Advertising note

Display advertising may return after the site meets Google publisher content standards. While ads are paused, the workshop and guides remain free to use.