JSON5 Formatter
Free JSON5 formatter. Accepts JSON with comments, trailing commas, and other relaxed syntax, then outputs strict JSON. Useful for config files that drifted from spec.
Runs in your browserUpdated Apr 26, 2026
JSON5 Input
Output
Frequently asked questions
›What is JSON5?
A superset of JSON that allows comments, trailing commas, unquoted keys and a few other conveniences. It's the format of many config files (tsconfig, devcontainer, babel) and drift-prone hand-edited JSON.
›Does it handle single-quoted strings?
This tool handles the most common JSON5 drift — `// comments`, `/* block comments */` and trailing commas. For the full JSON5 spec (unquoted keys, single quotes, hex numbers) paste into a proper JSON5 parser locally.
›What does the output look like?
Strict, spec-compliant JSON — 2-space indented. Safe to feed to any JSON.parse or schema validator.
›Is it free?
Yes — fully free, in-browser, no signup.