Format, beautify, minify, and validate JSON in your browser. Syntax highlighting, error detection, and key sorting — free, instant, no signup or upload.
0 characters
100% browser-based
Runs locally in this tab
No upload required
Your files never leave this device
Nothing is stored
Close the tab and the input is gone
Instant results
No queue and no server wait
Paste a minified payload or a messy dump from logs and get a readable tree in one pass. Switch between 2-space, 4-space, or tab indentation so the result matches the rest of your codebase. Nested objects and arrays keep their structure, which makes API responses, config files, and webhook bodies much easier to scan.
When you need the compact form for storage, network payloads, or a gist, toggle minify to strip extra whitespace while keeping valid JSON. The workspace reports original size versus formatted size so you can see what you gained. Pair it with key sorting when you want a stable, diff-friendly output.
Invalid JSON is highlighted with the line and column of the first problem, plus a readable message — a missing comma, a trailing comma, or an unquoted key. You can fix the input in place instead of guessing. Structure stats (depth, key count, arrays, root type) help you understand a payload before you ship it.
This JSON formatter runs entirely in your tab. Secrets in access tokens, environment dumps, or customer payloads never leave the device. There is no account gate and no file upload. That is the right default for a developer tool that often sees credentials sitting next to real data.
Drop a JSON string into the input. Minified one-liners, pretty-printed files, and copied API responses all work. You do not need to upload a file.
Pick 2 spaces, 4 spaces, or tabs for a readable tree. Turn on minify for a compact payload, or sort keys when you want a stable order for diffs.
Valid JSON is highlighted in the output. If the input is invalid, the error points to the line and column. Stats show size, depth, keys, and the root type.
Copy the output when it looks right and paste it into your editor, ticket, or request body. Clear the workspace when you are done — nothing is stored on a server.
Straight answers on privacy, limits, and how the workspace behaves.
More from Developer.
Validate JSON in real time with line and column errors. Auto-repair trailing commas, unquoted keys, and single quotes — free, private, no signup or upload.
Developer
Test regular expressions against sample text
Developer
Encode and decode Base64 in your browser with Unicode, URL-safe alphabet, and live conversion. No upload, no signup — free online Base64 encoder and decoder.
Developer
URL-encode and decode query strings and full URLs with encodeURI or encodeURIComponent. Component vs full URI, live conversion — free, private, no upload.
Developer
Encode and decode HTML entities with named or numeric modes, special characters or all characters, and a live preview. Free developer tool, no upload.
Developer
Decode JWT tokens in your browser: inspect header, payload, claims, and expiration. The signature is not verified. Free, private, no signup or upload.
Developer