JSON Formatter / Validator
Pretty/minify, error line/col, key sort.
How to use
Enter JSON and Mode into JSON Formatter / Validator and press Run — or just type, live results update as you edit. TextMeter computes the answer instantly with a pure JavaScript engine (Web Worker for heavy inputs) on this page. Nothing is sent anywhere: no signup, no server round-trip, same inputs always give same outputs.
Steps
- Open the tool below (or scroll to the interactive JSON Formatter / Validator).
- Enter JSON and Mode.
- Press Run (Ctrl+Enter) — or keep typing for live results.
- Copy the answer, download it, or share the link.
FAQ
Is JSON Formatter / Validator really free?
Yes — free with no signup, no credits and no limits on this tool. It is supported by clearly labeled ads placed away from the buttons, never by paywalls.
Is anything I type into JSON Formatter / Validator sent to a server?
No. Every keystroke is computed with a pure JavaScript engine (Web Worker for heavy inputs) inside this page. Close the tab and your data is gone — unless you explicitly download or share it.
What should I enter in "JSON"?
Put your json here — for example: {"b":2,"a":1}. Leave the defaults first to see how it works, then adjust. Every field is validated with a plain-language message if something is off.
I normally use SmallSEOTools — why switch?
If you are tired of thin counter pages wrapped in ads, with no real editing toolkit behind them, TextMeter is the alternative: Unicode-correct counts at 100k-word scale plus a full cleaning and transform suite.
How accurate is JSON Formatter / Validator?
Everything runs on your device, so results are instant and repeatable — same inputs, same outputs, no server involved.
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Free alternative
Free alternative to WordCounter and SmallSEOTools for counting and transforming text — Unicode-correct counts at 100k-word scale plus a full cleaning and transform suite. WordCounter vs SmallSEOTools vs TextMeter.
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