Does JSONBlitz ever store or log my JSON data?

No. Processing is entirely local — JavaScript runs in your browser tab with no network calls. Nothing is written to any server, database, or log. Closing the tab discards everything.

Is JSONBlitz safe for API keys and authentication tokens?

Yes. Because no data leaves your browser, pasting credentials or tokens carries no more risk than opening a local text file. The data never touches a network.

Can my employer or network administrator see what I paste?

No. JSONBlitz makes no external network requests during normal use. Traffic monitoring tools would see only the initial page load, not any subsequent data.

What is stored in localStorage?

Only session history for the Recent Sessions panel — the last few JSON inputs you processed, stored locally in your browser. This can be cleared at any time with the Clear all button in the History panel.

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JSONBlitz 100% PRIVATE

Input — paste anything

Private JSON Formatter — Your Data Never Leaves Your Browser

Many popular JSON formatting tools send your data to their servers — creating a risk when your JSON contains API keys, authentication tokens, database credentials, or personal data. JSONBlitz processes everything locally in your browser using JavaScript. There is no server, no database, no logging. Paste sensitive JSON safely, even in air-gapped or restricted environments. Works fully offline once loaded.

Ready — paste JSON or any text containing JSON

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Tree view appears here after processing

Click nodes to copy JSONPath • Single-click a leaf to copy value

Formatted output appears here...

Process JSON to generate code...

Insights appear after processing

Shows what JSONBlitz changed to fix your JSON. Process some broken JSON first.

No changes recorded yet.

JSONBlitz — Fix Invalid JSON Instantly. Free Online JSON Formatter & Validator 2026.

JSONBlitz is a free, 100% private, client-side JSON formatter, validator, and repair tool. Paste messy JSON, console logs, API responses, or stack traces — JSONBlitz finds the JSON, fixes it automatically, and gives you clean output plus TypeScript interfaces, Zod schemas, and Python TypedDict code. Nothing ever leaves your browser.

How to Fix Invalid JSON Online Free

Paste any broken JSON into JSONBlitz. Common errors like trailing commas, single quotes instead of double quotes, unquoted keys, and JavaScript comments are all fixed automatically in one click. The status bar shows exactly what was repaired.

Fix Trailing Comma JSON Error

Trailing commas in JSON objects and arrays are one of the most common errors when copying JSON from JavaScript code. JSONBlitz removes trailing commas automatically and shows you what changed in the Before/After tab.

Extract JSON from Console Logs and Error Messages

Paste a full console log, stack trace, terminal output, or Slack message that contains JSON. JSONBlitz automatically detects and extracts the JSON portion, even if it is buried in surrounding text. Works with ChatGPT and Claude AI output too.

Free TypeScript Interface Generator from JSON

Paste any JSON and click the TS+Zod tab to instantly generate recursive TypeScript interfaces, Zod validation schemas, and Python TypedDict classes. No signup required. Works completely offline.

100% Private JSON Tool — Safe for API Keys and Production Data

JSONBlitz processes everything locally in your browser — your JSON never leaves your device. No data is transmitted anywhere. Safe for API keys, authentication tokens, credentials, and sensitive production data.

Frequently Asked Questions

Does JSONBlitz ever store or log my JSON data?: No. Processing is entirely local — JavaScript runs in your browser tab with no network calls. Nothing is written to any server, database, or log. Closing the tab discards everything.
Is JSONBlitz safe for API keys and authentication tokens?: Yes. Because no data leaves your browser, pasting credentials or tokens carries no more risk than opening a local text file. The data never touches a network.
Can my employer or network administrator see what I paste?: No. JSONBlitz makes no external network requests during normal use. Traffic monitoring tools would see only the initial page load, not any subsequent data.
What is stored in localStorage?: Only session history for the Recent Sessions panel — the last few JSON inputs you processed, stored locally in your browser. This can be cleared at any time with the Clear all button in the History panel.