Runs in your browser

JSON Formateur & Minifier (Pretty & Minify)

Q: "I get an error"

"We show the line and column where the JSON is broken. If possible, the input is highlighted and you can jump directly to it."

Q: "Can I use JSON with comments (JSONC/JSON5)?"

"Standard JSON does not allow comments. Turn on “Strip comments before parsing” if needed (not fully compatible)."

Q: "Large JSON is slow"

"Parsing and formatting run in a Web Worker to keep input responsive. Tree view is disabled automatically for large inputs."

Q: "Is my data sent anywhere?"

"Non. Formatting, minifying, and validation run entirely in your browser."

Q: "I see \\uXXXX escapes"

"Toggle “Unicode escape” to control whether the output uses escape sequences."

Format or minify JSON, with clear error locations. Everything runs in your browser.

Your input is never sent to a server (processed locally) Safe to use even with sensitive data

Indent Advanced options

Cmd/Ctrl+Enter to format / Cmd/Ctrl+Shift+Enter to minify

Idle

Entr?e (JSON)

Lines 0 Chars 0 Size 0 B

Your input is processed locally in the browser and never sent to a server.

Sortie

Lines 0 Chars 0 Size 0 B

Copier or download the output.

Formatted or minified JSON will appear here...

How to use Shortcuts FAQ Outils associ?s

Options

Advanced options

Sort keys Sort object keys in ascending order. Ajouter trailing newline Append a newline at the end of the output. Unicode escape Escape non-ASCII characters as \uXXXX. Strip comments before parsing Retirers // and /* */ comments (JSONC/JSON5-like). Commented JSON is not standard JSON. Compatibility is not guaranteed.

How to use (3 steps)

1. Paste

Paste JSON into the input panel.

2. Format/Minify

Click Format or Minify to generate the result.

3. Copier

Copier the output and you are done.

Shortcuts

Shortcuts work when the input has focus.

Cmd/Ctrl + Enter

Format

Cmd/Ctrl + Shift + Enter

Minify

Cmd/Ctrl + L

Clear (with confirmation)

Example of formatted JSON

Before

{"name":"A","items":[1,2],"meta":{"ok":true}}

After

{
  "items": [
    1,
    2
  ],
  "meta": {
    "ok": true
  },
  "name": "A"
}

Ajouters indentation and line breaks for readability
Sort keys to keep a consistent order

Remarques & terminology

What is JSON formatting?

Pretty-printing JSON adds line breaks and indentation so the structure is easy to read.

What is JSON minify?

Minifying removes whitespace to make the output as small as possible.

Common errors

Trailing commas, missing quotes, and mismatched brackets are typical. This tool shows line/column details.

Tip

Indent 2 keeps diffs smaller, while indent 4 is easier to scan. Choose based on your workflow.

FAQ: JSON formatter & minifier

I get an error

We show the line and column where the JSON is broken. If possible, the input is highlighted and you can jump directly to it.

Can I use JSON with comments (JSONC/JSON5)?

Standard JSON does not allow comments. Turn on “Strip comments before parsing” if needed (not fully compatible).

Large JSON is slow

Parsing and formatting run in a Web Worker to keep input responsive. Tree view is disabled automatically for large inputs.

Is my data sent anywhere?

Non. Formatting, minifying, and validation run entirely in your browser.

I see \uXXXX escapes

Toggle “Unicode escape” to control whether the output uses escape sequences.