Developer tools
15 free developer tools · Encode, format, generate
Format data, inspect a token, test a pattern or generate an identifier. These utilities process the text you enter in your browser, so you can work without uploading payloads.
All developer tools
- JSON formatter & validator Beautify, minify and validate JSON with error locations.
- JSON ↔ YAML ↔ XML Convert between JSON, YAML and XML in any direction.
- JWT decoder Decode a JWT and inspect its claims and expiry.
- Base64 encode & decode Encode or decode Base64, including URL-safe variants.
- Password generator Cryptographically random passwords with a strength readout.
- URL encode & decode Percent-encode or decode URLs, and inspect the parts.
- HTML entity encode & decode Escape HTML special characters, or decode entities back.
- JSON ↔ CSV converter Convert between JSON arrays and CSV, both directions.
- UUID generator Generate random v4 or time-ordered v7 UUIDs in bulk.
- Hash generator MD5, SHA-1, SHA-256, SHA-384, SHA-512 and CRC32 at once.
- Color converter Convert HEX, RGB, HSL and HSV, with WCAG contrast checks.
- Regex tester Test a regular expression with live match highlighting.
- Cron expression generator Explain a cron expression and see its next run times.
- QR code generator Make QR codes for links, Wi-Fi, email or contacts.
- Unix timestamp converter Epoch to date and back, with the unit auto-detected.
Guides
- JSON vs YAML vs XML: choosing and converting formats Compare JSON, YAML and XML for APIs, configuration and documents. Check what may change when converting attributes, types and mixed content.
- Base64, encryption and hashing: what each one does Understand the difference between encoding, encryption and hashing, with a Base64 example and common mistakes to avoid when working with tokens.
- How to read a JWT header, payload and claims Decode a signed JWT, understand its expiry and audience claims, and learn why reading the payload does not verify that a token can be trusted.
- Cron syntax explained with schedule examples Read the five cron fields, try common schedules and avoid mistakes with wildcards, day-of-week rules and timezones. Includes a field-by-field example.
- How to check a download with a SHA-256 checksum Compare a downloaded file’s hash with a trusted reference. Find checksum commands and understand why a matching hash alone does not prove a file is safe.