JSON Formatter & Validator — Pretty Print, Minify & Fix JSON Online

JSON encodes objects, arrays, strings, numbers, booleans, and null in a plain-text structure browsers and servers parse with JSON.parse. APIs return JSON; package.json, tsconfig.json, and cloud config files use it. Raw responses are often minified — one long line that is hard to read in logs or tickets.

Pretty printing adds indentation and line breaks so you can see nesting at a glance. Minifying removes whitespace to shrink payloads. Both operations require valid JSON first, which is why formatting and validation belong in the same tool.

Backend and frontend developers debug API responses before mapping fields in code. QA engineers paste webhook payloads to confirm structure after integration tests. DevOps staff inspect config exports from Kubernetes, Terraform, or CI pipelines. Support teams format customer-uploaded JSON attachments to read error details faster.

Data analysts loading JSON exports from analytics APIs use tree view to navigate without writing scripts. Students learning HTTP and REST visualize nested objects interactively. Technical writers format JSON snippets for documentation with consistent indent.

Paste or load your document into the input editor. The tool parses with the same JSON.parse rules your browser and Node.js use. Valid JSON shows a green badge plus stats: root type, total object keys, maximum nesting depth, and serialized byte size.

Invalid JSON shows a red badge, the parser error message, and when available the line and column where parsing stopped. Click Try Fix JSON from the error panel to attempt automatic repair, then re-read the validation badge.

Pretty print (Format) expands JSON with your chosen indent — 2 spaces is the most common default for readability. Use it when reading logs, reviewing API contracts, preparing documentation, or comparing two payloads side by side.

Minify compacts JSON to a single line with no extra spaces. Use it before sending smaller webhook bodies, storing compact snapshots, or matching production wire format. The tool keeps your original input in the editor until you click Format or Minify to replace it.

Fix JSON applies safe transformations: removes UTF-8 BOM, strips block and line comments, replaces curly smart quotes with straight quotes, deletes trailing commas before closing braces or brackets, normalizes Python True/False/None to JSON true/false/null, and converts simple single-quoted strings to double quotes.

Each change is listed in a summary panel so you know what was modified. Complex errors — unclosed brackets, truncated files, or invalid numbers — may still need manual editing. Fix JSON is a helper, not a guarantee of valid output.

After validation succeeds, switch from Code to Tree view. Objects and arrays expand and collapse. Keys are color-coded by type: strings, numbers, booleans, null, and nested structures. String values that look like image URLs show a hover preview thumbnail.

Expand all and Collapse all buttons help with large documents. Tree view is ideal when you need to find one field deep inside a nested API response without scrolling through formatted text.

Click Sort keys to reorder object properties recursively A–Z at every level. Enable Sort keys on format to apply sorting automatically whenever valid JSON is parsed. Sorted output makes diffs stable when comparing two versions of the same config file.

Upload accepts .json and plain text files. Drag a file onto the dashed drop zone. Example buttons load ready-made samples — a simple object, a nested API-style response, and a business data structure.

URL load fetches public JSON over HTTPS through a server proxy that blocks private networks and limits response size. Use it for open APIs and test endpoints — never paste URLs that require authentication or contain sensitive data.

Two spaces is the default in most JavaScript projects and matches common style guides. Three and four spaces suit teams with deeper nesting preferences. Tab uses a literal tab character per level. Compact in the indent dropdown formats without extra whitespace similar to minify.

This page handles JSON only. If you need CSV conversion, use the JSON to CSV or CSV to JSON tools. If you need XML or YAML alongside JSON, use the API response formatter. Stay here when the job is validate, beautify, minify, or explore JSON specifically.

Paste, upload, and local formatting never leave your browser. Parsed content is not logged on our servers. URL fetch is the only feature that contacts our backend — and only to retrieve the public URL you provide. Clear browser storage to reset saved editor sessions.

Trailing commas after the last array item or object property break strict JSON parsers. Single quotes around strings are invalid — JSON requires double quotes. Unquoted keys, undefined values, and comments are JavaScript object literal features, not valid JSON. Smart quotes from word processors cause silent parse failures until replaced.