Guide
Format JSON online (free)
JSON from APIs and logs often arrives minified or broken. Paste it into our formatter to prettify for reading, minify for payloads, or catch syntax errors before deployment—all processing stays in your browser.
When to prettify vs minify
Prettify for code review, debugging, and docs. Minify for production transfers where bytes matter. Never minify if humans still edit the file locally.
Common errors
Trailing commas, single quotes, and unquoted keys break strict JSON—fix or convert from JavaScript object literals. Large files may slow the tab; split arrays if needed.
Privacy for developers
Because parsing is local, configs with internal hostnames or schema drafts are not uploaded to our servers—ideal for quick checks on VPN or offline machines.
FAQ
Is there a file size limit?
Very large JSON may hit browser memory limits. For multi-megabyte logs, use CLI tools or split files.
Does it validate JSON Schema?
It validates syntax (parseable JSON). Schema validation is a separate step in your CI pipeline.
Can I format JSON with comments?
Standard JSON has no comments. Strip comments or use JSON5 tools elsewhere before pasting here.
Is my data stored?
No—processing happens in your session. Refresh clears the editor state.