JSON Formatter
Pretty-print, minify, and validate JSON in your browser
Accepted upload: .json · max 5 MB. Other formats are not supported — paste JSON or upload a .json file.
Use Format, Minify, and Validate above. Tap an error location to jump the caret.Shortcuts (while this tool is focused): Ctrl/Cmd + Enter format, Ctrl/Cmd + Shift + M minify. Click an error location to jump the caret.
About this JSON formatter
Paste JSON or upload a .json file (up to 5 MB) to pretty-print with 2-space indentation, minify to a single line, or validate syntax. Jump to a reported line and column, then copy or download the result as formatted.json. Processing runs entirely in your browser.
How to use
- Paste JSON into the editor or upload a .json file (5 MB max). You can also load the built-in sample.
- Tap or click Format (2-space indent), Minify, or Validate. These buttons work on phones and desktops.
- If validation fails, use the line/column link to jump to the problem in the input.
- Copy the result or download it as formatted.json.
Format, minify, and validate
Formatting adds readable indentation without changing data. Minification removes unnecessary whitespace for smaller payloads. Validation checks that the text is valid JSON according to the standard parser; it does not check schema, types, or business rules.
- Format uses two spaces per indent level.
- Minify produces compact output suitable for APIs or logs.
- Invalid JSON stops formatting and surfaces a parse error location when available.
Common uses
- Inspect API responses or config files before committing them.
- Minify JSON for production while keeping a pretty version locally.
- Find syntax mistakes quickly using validate and go-to line/column.
Tips
- Large files near the 5 MB limit may feel slower; split very big payloads if the tab struggles.
- After validate fails, fix the reported line first—trailing commas and unquoted keys are frequent causes.
- Use minify only when whitespace is not needed; some diff tools prefer formatted JSON.
- On a desktop keyboard, with the editor focused, Ctrl/Cmd+Enter formats and Ctrl/Cmd+Shift+M minifies. Shortcuts are optional—phones and tablets should use the buttons. Some browsers reserve Ctrl+Shift+M for their own UI.
Privacy
Your JSON is processed locally in the browser. It is not uploaded to ToolsArk servers for formatting. Closing the tab clears in-memory content unless you copy or download it yourself.
Limitations
- Upload size is capped at 5 MB per file.
- There is no JSON Schema or custom rule validation—only syntax.
- Extremely nested or long single-line JSON may be hard to navigate even when valid.
Frequently asked questions
Common questions about the JSON Formatter.
How does JSON Formatter work?
Paste or upload JSON, then Format, Minify, or Validate. ToolsArk parses with JSON.parse and pretty-prints or minifies with JSON.stringify in your browser. Invalid JSON shows a line and column you can jump to.
Does my JSON leave my device?
No. Formatting and validation run entirely in your browser. ToolsArk does not upload your JSON to a server.
What file types can I upload?
Upload a .json file up to 5 MB. Larger or non-JSON files are rejected before parsing.
Does it support JSON5 or schema validation?
No. It expects standard JSON only. There is no JSON5/relaxed syntax mode and no schema or sort-keys feature in this tool.
What keyboard shortcuts are available?
On desktop, with the editor focused: Ctrl/Cmd+Enter formats, and Ctrl+Shift+M (Windows/Linux) or Cmd+Shift+M (macOS) minifies. Shortcuts are optional. On phones and tablets—or if a browser captures the key combo—use the Format, Minify, and Validate buttons instead. Click a validation error to move the caret to that location.
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