Guides
Practical developer how-tos, no fluff.
Clear, step-by-step guides to the everyday dev tasks — formatting, encoding, validating and generating — each backed by a free tool that runs entirely in your browser.
How to Decode and Verify a JWT
Read the header and claims, check exp and nbf, and understand what signature verification does — and why you should never decode tokens on a server you don't trust.
Read guideHow to Encode and Decode Base64
What Base64 actually does, when to reach for the URL-safe variant, and how to encode files as well as text — without uploading anything.
Read guideHow to Format and Validate JSON
Beautify messy JSON, catch the exact parse error, and know when to minify vs. pretty-print — without uploading your data anywhere.
Read guideHow to Generate a QR Code (with a Logo)
Add a logo and brand colors without breaking scannability, and pick PNG vs. SVG correctly for screen and print.
Read guideHow to Hash Text and Files (MD5, SHA-256)
Verify a file checksum, pick the right algorithm, and learn why MD5 and SHA-256 are the wrong tools for passwords.
Read guideHow to Test and Debug a Regular Expression
Flags, capture groups, greedy vs. lazy matching, and the small mistakes that make a regex match too much or nothing at all.
Read guideSkip the reading — just use the tools
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