10 Free Online Tools Every Developer Needs in 2026

Every developer needs a solid toolkit. Here are 10 free tools you can use right now — no signup, no downloads, no BS. 1. JSON Formatter & Validator Paste messy JSON, get it formatted and validated instantly. Catches syntax errors with line numbers. Try it: JSON Formatter 2. Base64 Encoder/Decoder Encode strings, decode tokens, handle file-to-base64 conversions. Essential for API debugging. Try it: Base64 Tool 3. JWT Decoder Decode JWT tokens without sending them to a third party. See header, payload, and verify signatures locally. Try it: JWT Decoder 4. Regex Tester Write and test regex patterns with real-time matching, capture groups, and common pattern library. Try it: Regex Tester 5. Cron Expression Builder Build cron expressions visually. See next 10 execution times. Never guess cron syntax again. Try it: Cron Builder 6. SQL Formatter Format messy SQL queries with proper indentation. Supports SELECT, INSERT, UPDATE, CREATE TABLE. Try it: SQL Formatter 7. Color Picker & Converter Co