JSON Formatter & Validator

Paste JSON, get it formatted, validated, minified, or key-sorted — with the exact line and column of any error. Safe for API keys, customer records, and anything else you'd never paste into a random website, because this one never transmits it.

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Why a local-only JSON formatter matters

JSON payloads routinely contain bearer tokens, internal hostnames, customer PII, and unreleased data. Most online formatters post your input to their server to process it. This one runs JSON.parse and JSON.stringify in your own browser tab — open DevTools and watch the network panel stay empty. It also means there's no payload size cap: if your machine can hold it, this tool can format it.

Error messages that actually locate the error

Instead of "Unexpected token," validation failures report the line and column where parsing stopped, with the surrounding text quoted, so you can fix a missing comma in a 5,000-line file without hunting for it.