TASK

Format, validate, and repair malformed JSON

Take a JSON string (possibly minified, with trailing commas, or comments) and produce valid, indented JSON with error diagnostics.

1

JSON from APIs is often minified for transport, and JSON from humans often has errors (trailing commas, single quotes, comments). Formatting makes it readable; validation catches structural errors before parsing fails in production.
2

JSON Validator →
Paste the JSON. The tool reports whether it is valid and, if not, the exact location and nature of the syntax error (unexpected token, missing comma, unterminated string).
3

JSON Formatter →
Paste valid (or valid-ish) JSON to re-indent it with 2 spaces, sort keys if desired, and normalize whitespace for consistent diffs.
4

json-format → crc32
View recipe Open in Toolchain

Use the chain to validate-then-format in one pass: if validation fails you get the error; if it passes you get formatted output.

Frequently asked questions

Why does my JSON with comments fail validation?: Standard JSON (RFC 8259) does not allow comments. Some parsers (JSON5, JSONC used by VS Code) accept them, but strict JSON does not. Strip comments before sending to a strict parser, or use a JSONC-aware parser.
Can the tool fix trailing commas automatically?: Strict JSON forbids trailing commas. The validator flags them; some formatters can strip them during formatting. However, automatic repair can mask real errors — always review the diff after any auto-fix.

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Learn more

Want to understand why?

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Amazon Ion is a data format designed by AWS that supports both text and binary representations with identical semantics, and is a superset of JSON.

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