Free Developer Tools
Free developer utilities for the small, frequent jobs in a coding workflow. Format, validate, and minify JSON; encode and decode Base64 and URL/percent-encoding; convert Unix timestamps to readable dates; and generate QR codes, UUIDs, and strong passwords. Each tool is built for speed and clarity — live output as you type, clear error messages with the problem location, and a copy button on every result. Crucially, everything runs locally in your browser, so the code, tokens, JWTs, and payloads you paste in are processed on your own machine and are never uploaded to a server or logged. That makes these safe to use even with snippets you would not paste into an unknown online tool.
Convert text to Base64 and back. Works with full Unicode via UTF-8, and runs entirely in your browser so nothing is uploaded.
A fast, secure hash generator that creates cryptographic digests from any text input. Choose from SHA-256 (default), SHA-1, SHA-384, or SHA-512 algorithms—all processed in your browser with zero data collection.
Paste JSON to pretty-print it, validate it, or minify it. Errors are reported with a clear message so you can find the problem fast.
Paste JSON to check whether it is valid. If it isn't, you get the error plus the line and column where it breaks; if it is, you get a clean formatted copy.
A JWT decoder transforms the cryptic Base64-encoded segments of a JSON Web Token into readable JSON and human-friendly dates. Copy any JWT, paste it in, and instantly see what claims it contains—perfect for debugging authentication, understanding token payloads, and checking expiration without needing the secret key.
Turn a link or any text into a QR code and download it as a PNG. It’s generated in your browser — what you enter is not uploaded — and there’s no watermark.
Test JavaScript regular expressions instantly in your browser. Enter a pattern, add flags like g for global or i for case-insensitive, and see all matches highlighted with counts. Perfect for debugging regex before you use it in code.
Convert a Unix timestamp to a readable date — in both UTC and your local time — or turn a date into a timestamp. Handles seconds and milliseconds.
Encode text for safe use in a URL, or decode a percent-encoded URL back to readable text. Runs in your browser with full Unicode support.
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Frequently asked questions
Are these developer tools safe for sensitive data?
Yes. They run fully client-side in your browser — nothing is uploaded. For example, the JWT decoder decodes locally and never transmits or verifies your token.
Do you store anything I paste?
No. There is no server processing, so pasted JSON, Base64, and other input stay in your browser.
Which hash algorithms are supported?
SHA-1, SHA-256, SHA-384, and SHA-512 via the Web Crypto API. MD5 is intentionally not offered because it is insecure.