About JSONBeautify

What this is

JSONBeautify takes pasted JSON and makes it readable. Two panes: you paste on the left, formatted output appears on the right, and validation runs on every keystroke — no submit button, no upload step, nothing to wait for.

There are four real actions. Format (2 spaces) and Format (4) run JSON.stringify(parsed, null, indent). Minify runs JSON.stringify(parsed) with no whitespace, for when the payload has to fit inside a config file or a test fixture. Auto-Repair makes three regex substitutions and then tries to parse again. Sample, Clear, and Copy do exactly what their labels say.

The status bar reports the parsed type, array length when the root is an array, and output size in bytes; the footer reports line and character counts. On failure the output pane carries the engine's own error text, unedited — including V8's position N, which the cheatsheet shows how to convert to a line and column.

Why "100% client-side" matters more here

There is no server endpoint for your JSON to travel to. Not "we delete it after" — there is nowhere for it to go. The page is static HTML and a small script; the formatting is JSON.parse and JSON.stringify running inside your own browser.

For most tools that claim this, it is a privacy slogan. For a JSON formatter it is the actual product. Think about what gets pasted here: a production API response, a webhook body, a database dump pulled to reproduce a bug, a config with a password field somebody left in. That content routinely carries bearer tokens, API keys, customer emails, and internal hostnames. A formatter with a backend would be receiving other people's incidents as log lines, forever, and would have to be trusted not to read them. This one cannot, because there is no receiving end.

If your paste contains live credentials, treat this page as a viewer rather than a cleaner — and rotate anything that was ever pasted somewhere you do not control.

What Auto-Repair actually does

Three regex substitutions, in this order: single-quoted strings become double-quoted, a comma directly before } or ] is dropped, and a bare key: gets its key quoted. If the result parses, it replaces your input and is formatted at two-space indent. If it still fails, the status line says so and shows the engine's error.

That is the whole feature, and it has a sharp edge: the first substitution is textual, so it will happily rewrite an apostrophe inside a value. Auto-Repair is a diagnostic for "why won't this parse," not a preprocessing step for a pipeline. For repair at scale, use a proper library — the alternatives page covers the ones that do it properly.

What this tool does NOT do

• No JSON Schema validation. It answers "is this well-formed JSON," never "does this match my contract." A payload with every field misspelled is valid JSON and will pass.
• No querying or transformation. No JSONPath, no jq, no filtering. The cheatsheet has the jq one-liners that do.
• No key sorting, no canonicalisation. Key order is whatever the engine produced on parse. If you need deterministic byte-identical output for hashing or signing, that is RFC 8785, the JSON Canonicalization Scheme, and this page does not implement it.
• No comments, no JSONC. The parser rejects them, and Auto-Repair does not strip them.
• No number-precision protection. A 22-digit ID loses digits before you see it — explained here.
• No keyboard shortcuts. Buttons only. No Ctrl+Enter to hunt for.

Who runs it

One person, in the United States. jsonbeautify.net is one of a small family of single-purpose developer utilities — alongside curlparse.net, sqlformat.net, and regexcalc.net. No company, no sales team. The person who reads your bug report is the person who fixes the tool.

Why it's free

A small, non-blocking ad slot covers the domain and the hosting. That is the entire business model. Client-side tools are cheap to run: no backend to scale, no database to migrate at two in the morning, no usage spike to pay for. The privacy policy is specific about what little is collected, and the changelog is dated so "actively maintained" is something you can check rather than something you take on faith.

Bugs, a bad repair, or a claim on this site you think is wrong: contact. Defect reports get the most replies.