Paste the document
Drop in API responses, configs or AI-generated JSON — or load the sample. Validation runs as you type with exact line and column on errors.
Free tools · Data
Paste JSON, read the answer.
Pretty-print, validate and minify with exact error positions and document stats — computed on your device, never uploaded.
Format · validate · minify
Paste JSON, read the answer.
Pretty-print, minify, sort keys and validate with line-and-column errors as you type. Your document never leaves this page.
Valid JSON appears here with size, depth and key stats.
How it works
Three steps, all on your device.
The same parse-and-print loop behind every API client and config linter, running here without accounts or uploads.
Shape the output
Pick 2-space, 4-space or tab indent, minified mode, or recursive key sorting for stable diffs and configs.
Copy it back
Take the formatted output with size, depth and key stats attached — handy context for tickets and code review.
Questions
Formatting JSON, answered.
If you manage servers by hand, see the engineering services behind this tools series.
Is my data uploaded anywhere?
No. Parsing and formatting run entirely in your browser with the platform JSON parser — the page makes no network requests with your data. You can verify this in your browser's developer tools or disconnect from the network after the page loads.
What do the error messages mean?
Every error names its line and column: trailing commas, missing quotes, single-quoted strings and unquoted keys are the usual suspects — none are valid JSON. Fix the marked spot and the output updates instantly.
Does sorting keys change my data?
No — key order carries no meaning in JSON, so sorting only reorders object members (arrays keep their order). It is ideal for stable diffs, snapshot tests and tidy configs.
Is there a size limit?
The page handles multi-megabyte documents comfortably since everything runs locally. Extremely deep nesting (tens of thousands of levels) can exhaust the parser's call stack — such payloads are pathological and usually a sign of a runaway generator.
Can it convert JSON to YAML or CSV?
Not yet — this tool formats, validates and minifies JSON. Converters between JSON, YAML and CSV are on the roadmap as separate tools in the Data family.