InTheTab We never get your data

JSON formatter and validator without uploading

Paste JSON on the left. Pretty prints it with 2-space indentation; Minify strips all whitespace. If it isn’t valid JSON, you get an error instead.

How to format JSON

  1. Paste your JSON. An API response, a config file, a log line. It stays in this tab.
  2. Click Pretty or Minify. Pretty indents with 2 spaces, one value per line. Minify puts it all on one line.
  3. Copy the result. Copy puts the output on your clipboard. If the input isn’t valid, the error appears under the buttons.

Good to know

  • Formatting is validation. The text is parsed with your browser’s own JSON parser, then written back out. If parsing fails, there’s no output, just the parser’s message. In Chrome and Edge it gives the position, line and column, e.g. Expected double-quoted property name in JSON at position 7 (line 1 column 8).
  • Strict JSON only. Comments, trailing commas, single quotes and unquoted keys are errors, as are NaN and undefined. JSON5 and JSONC files will need those removed first.
  • Minify removes whitespace between values only. Spaces and line breaks inside strings are kept exactly.
  • Values are re-written, not copied. 1.0 becomes 1, 1e3 becomes 1000, escapes like é become the character itself, and if a key appears twice, the last value wins.
  • Very large integers lose precision. Numbers are read as JavaScript numbers, so integers beyond 9,007,199,254,740,991 (253 − 1), such as some 64-bit IDs, come out rounded. Keep those as strings.
  • Key order is kept, with one exception. Keys that look like whole numbers ("2", "10") are moved to the front in numeric order. That’s how JavaScript objects work.

Your JSON stays on your device

JSON often holds things you shouldn’t paste into a stranger’s website: customer records, API keys in a config file, internal responses from production. Here it is parsed and formatted inside this browser tab, by your browser’s built-in JSON support.

The page’s security policy tells your browser to block uploads, so your data can’t leave your device even by accident. You can check: open your browser’s developer tools, watch the Network tab, and format something. How InTheTab works

You’ll also see a few small requests to Google Analytics. That’s our visit counter, and it never receives your files. Privacy policy

Questions

Is it safe to format JSON with secrets or personal data here?

Yes. The JSON is never sent anywhere. We never get your files or text: the site has no accounts, and its only analytics, Google Analytics, counts visits without ever seeing what you add here.

How do I find the error in invalid JSON?

Click Pretty. The message under the buttons comes from your browser’s parser and usually says what it expected and where, as a character position or a line and column. The most common causes are a trailing comma, a missing comma or single quotes.

Can I change the indentation?

No. Pretty always uses 2 spaces, and Minify uses none.

Does it work offline or with large files?

Once the page has loaded, formatting needs no connection. Size is limited by your device’s memory rather than a fixed cap, though very large pastes can make the text box slow.