The best productivity tools are the ones you don't notice — they're just there when you need them, fast, and then out of the way. Here are ten developer tools we reach for constantly.
1. JSON Viewer
Paste raw API response JSON and instantly get a collapsible tree, syntax highlighting, and validation. Search within the tree. Convert to YAML or CSV. The JSON Viewer replaces three separate tools.
2. JWT Decoder
Paste a JWT token and the JWT Decoder immediately shows the decoded header, payload, and expiry time. Essential when debugging auth flows — no more manually base64-decoding each segment.
3. UUID Generator
Generate v1 or v4 UUIDs in any quantity. Copy all to clipboard in one click. The UUID Generator sounds trivial, but having it instantly accessible saves constant context-switching.
4. Hash Generator
Input text or a file, get MD5, SHA-1, SHA-256, and SHA-512 hashes simultaneously. The Hash Generator is indispensable for verifying file integrity and testing hash comparisons.
5. Base64 Encoder
Encode and decode text, file contents, or image data to/from Base64. The Base64 Encoder handles binary data correctly and shows both encoded and decoded views side by side.
6. Diff Checker
Paste two blocks of text or code and see exactly what changed, line by line. The Diff Checker is much faster than firing up a git diff for quick comparisons.
7. URL Encoder
Encode and decode URLs with percent-encoding. The URL Encoder handles query strings correctly and shows the decoded version inline — useful when debugging API calls with complex parameters.
8. Regex Tester
Write a pattern, paste your test string, see matches highlight in real time with capture group breakdown. The Regex Tester makes iterating on complex patterns fast and visual.
9. Cron Parser
Paste a cron expression like 0 9 * * 1-5 and the Cron Parser tells you in plain English: "At 9:00 AM, Monday through Friday." Also shows the next 5 scheduled runs.
10. Color Picker
Pick a colour visually, or paste a HEX/RGB/HSL value, and get instant conversion to all formats. The Color Picker also shows contrast ratios for accessibility checking.