Automatically Removing Illegal Trailing Commas from JSON
Trailing commas are completely valid in JavaScript, TypeScript, and Python—which is why developers routinely leave a comma after the last property in an object or array. Unfortunately, strict JSON rejects trailing commas every single time.
Why does this error occur?
Modern code formatters like Prettier encourage trailing commas in JS/TS files because they produce cleaner Git diffs. When a developer copies an object literal from a TypeScript file or hand-edits a JSON payload and deletes the last line without removing the preceding comma, the JSON becomes invalid.
Standard JSON parsers immediately throw errors like "Expected double-quoted property name in JSON" or "Unexpected token ] in JSON" because RFC 8259 strictly forbids trailing commas.
How is it solved?
Paste your broken JSON into DataPurge above. The JSON repair engine scans for commas followed by whitespace and a closing brace } or bracket ], as well as accidental duplicate commas like [1, , 2].
It strips every illegal trailing comma cleanly without touching commas inside string values, then validates and pretty-prints the repaired JSON.
Why should you use 100% Client-Side (Zero-Telemetry)?
Even a small typo like a trailing comma often happens in API payloads containing user data, auth headers, or private configuration objects. There is no reason to transmit private payloads to an external server just to remove a comma.
DataPurge repairs your JSON 100% inside your browser’s local memory with zero telemetry and instant execution.