JSON Formatter
Format, minify, and validate JSON online. Client-side only — your data never leaves your device.
Processed in your browser. Files never leave your device.
How it works
- Paste JSON or open a file.
- Choose pretty-print or minify (and optional key sort).
- Format, then copy or download.
Format and validate JSON locally—no upload
A JSON formatter is one of the most common developer utilities online, but most hosted beautifiers receive your body on a server. Structura formats and validates JSON entirely in the browser so logs, API responses, and configs with tokens or PII never need to leave your machine for a simple pretty-print.
Use it to confirm a payload is strict JSON before shipping it, to minify for storage or transport, to sort keys for stable diffs in reviews, or to clean up unreadable single-line responses from clients and terminals.
What the tool produces
- Strict JSON validation with a clear parse error when input is invalid
- Pretty-print with two-space indentation
- Minify for compact output
- Optional key sorting
- Status summary with byte size and top-level key or item counts
Worked example
Input: {"b":1,"a":2}. Enable Sort keys and Format. Output becomes a readable
object with keys ordered a then b. Toggle Minify instead when you
need a single-line string. If the input has trailing commas or comments (JSON5), Structura
rejects it—input must be strict JSON.
Privacy, retention, and limits
Formatting never uploads your JSON to Structura. Content is not retained as stored files on our side. Anonymous analytics may record that a format action ran and whether you used paste or a file chooser—not the JSON itself. Browser safety ceiling: about 5 MB. Free, no account.
After you have valid JSON, jump to JSON → TypeScript or JSON → Zod if you need generated code from the same example. Structura keeps those tools separate so each page stays focused for search and for the job you opened it to do. Start here whenever the first question is simply “is this valid JSON?” Use this page as the quiet first step in that workflow.
Related tools: JSON → TypeScript · JSON → Zod · CSV → JSON
FAQ
Does my data get uploaded or stored?
No. Conversion and cleaning run entirely in your browser. Structura does not upload your paste or file for processing and does not retain file contents on a server. Closing the tab clears the in-memory copy.
Is processing private / local-only?
Yes for the tool’s job. Your payload stays on the device. Optional Cloudflare Web Analytics may record page views and anonymous events such as tool runs, paste vs file, and copy/download—never the contents of your JSON or CSV.
What size limits apply?
About 5 MB as a browser safety ceiling. Larger inputs may freeze or crash the tab depending on your device.
What formats are supported?
Strict JSON text (paste or .json file). Trailing commas and comments are invalid JSON and will fail validation. Not YAML or XML.
What does validate mean here?
Structura parses with the browser’s JSON parser. If parsing fails, you see an error instead of formatted output.
Can I sort keys?
Yes. Optional key sorting helps produce stable diffs for reviews and commits.
Do I need an account?
No. All Structura tools are free to use without signup.
Need a data tool we don’t have yet?
Tell us what you are trying to convert, clean, or validate. We are prioritizing tools based on real requests. Looking for JSON diff, flatten/unflatten, or JSON → CSV?
Request a tool →