JSON Formatter Online
Format, validate, and minify JSON with syntax highlighting. Free, fast, and runs 100% in your browser.
Debugging API responses, inspecting webhook payloads, or reviewing configuration files — all require clean, readable JSON. This online JSON formatter transforms minified or messy JSON into beautifully indented output with syntax highlighting. Built-in validation catches errors instantly, pointing you to the exact line and character. Everything runs in your browser, so sensitive payloads never touch a server.
Feature Overview
| Feature | Details |
|---|---|
| Pretty-print | ✓ |
| Minify | ✓ |
| Syntax validation | ✓ |
| Error location | Line & character |
| Privacy | 100% client-side |
Frequently Asked Questions
Can I format very large JSON files?
Yes. The formatter handles files up to several megabytes. Performance depends on your device, but most JSON under 5 MB formats instantly.
Does it support JSONC (JSON with comments)?
Standard JSON does not allow comments. The validator will flag them as errors. Remove comments first or use the YAML converter for commented configs.
Can I switch between 2-space and 4-space indentation?
The formatter uses 2-space indentation by default — the most common standard for JSON files.