Format, validate, and convert between JSON, YAML, and XML. Free, fast, and privacy-focused.
You paste a wall of minified JSON from an API response. It's one line, 4,000 characters, no whitespace. You need to find why a key is missing. Without a formatter, you're scanning raw text character by character. With this tool, you click Format and the structure is immediately visible — nested objects indented, arrays on separate lines, the problem obvious in seconds.
That's the core use case. But the tool also handles YAML (Kubernetes manifests, GitHub Actions, Docker Compose) and XML (SOAP APIs, RSS feeds, Android resources) with the same one-click workflow.
Format / Prettify — use this when reading or debugging. Adds indentation and line breaks. A 1-line minified payload becomes a readable tree structure. The indentation level is 2 spaces, which is the most widely accepted style for both JSON and YAML.
Minify — use this before sending data over a network or embedding in code. Strips all whitespace. A 4KB formatted JSON file might become 2.8KB minified. Over thousands of API calls, that adds up. Always keep the formatted version in source control and minify as a build step.
Validate Only — use this when you just need a yes/no on whether the syntax is correct. Doesn't modify the data. Shows the exact line and character position of any error, which is far faster than reading the raw text yourself.
When debugging REST APIs, copy the raw response body from your browser's Network tab (or from Postman, Insomnia, or curl output) and paste it here. The formatter makes the structure immediately readable. You can then inspect the nesting, check field names, and verify data types before writing your parsing code.
For YAML, this is especially useful with Kubernetes manifests and CI/CD pipeline files where indentation errors cause cryptic failures. Paste the YAML, format it, and the structure becomes visually clear. Misaligned blocks stand out immediately.
JSON configuration files and API payloads don't need to be human-readable in production. Minifying removes all whitespace — spaces, tabs, newlines — producing the smallest valid representation. This reduces file size by 20-40% for typical JSON, which matters for large payloads sent over slow connections or stored in size-limited fields.
A good workflow: keep formatted JSON in your repository for readability and code review, then run it through the minifier as part of your build or deployment process. Never manually edit minified JSON — always edit the formatted source and re-minify.
All formatting and validation runs in your browser. Nothing is sent to a server. You can safely paste API keys, credentials, and internal configuration data — it never leaves your device.
The most common causes are trailing commas (JSON doesn't allow them after the last item), single quotes instead of double quotes around strings, or unescaped special characters inside string values. The formatter will show you the exact line and character where the error occurs. Copy the error message and look at that specific position in your input.
Format (prettify) adds indentation and line breaks to make data human-readable — useful for debugging and reading. Minify removes all whitespace to produce the smallest possible output — useful for production APIs and config files where file size matters. Both operations preserve the exact same data, just with different whitespace.
Yes, but browser performance depends on your device. Files up to a few MB format instantly. Very large files (10MB+) may take a few seconds. Since everything runs in your browser, there's no server-side file size limit. If you're working with extremely large files regularly, a desktop tool like VS Code with the Prettier extension may be more practical.
The JSON tab uses the standard JSON spec, which doesn't allow comments or trailing commas. If your file has comments (like a tsconfig.json or VS Code settings file), you'll need to remove them first. For JSONC files, strip the comments manually or use the text cleaner to remove comment lines before pasting.
Yes — all processing happens entirely in your browser. Nothing is sent to any server. You can verify this by opening your browser's network tab while using the tool; you'll see zero outbound requests triggered by your input. That said, as a general security practice, it's always wise to rotate any credentials after pasting them into any online tool.