devtoolbox.dev — 25 free online developer tools that run entirely in your browser. No data ever sent to a server.
| Tool | Description |
|---|---|
| JSON Formatter | Format, validate, and minify JSON |
| Base64 Encoder/Decoder | Encode and decode Base64 strings |
| JWT Decoder | Decode and inspect JSON Web Tokens |
| Hash Generator | Generate MD5, SHA-1, SHA-256, SHA-512 hashes |
| URL Encoder/Decoder | Encode and decode URL components |
| Timestamp Converter | Convert between Unix timestamps and dates |
| UUID Generator | Generate v4 UUIDs |
| Text Diff | Compare two texts side by side |
| Color Converter | Convert between HEX, RGB, HSL |
| Regex Tester | Test regular expressions with live matching |
| Cron Parser | Parse and validate cron expressions |
| YAML/JSON Converter | Convert between YAML and JSON |
| Markdown Preview | Live markdown rendering |
| Password Generator | Generate secure passwords |
| SQL Formatter | Format and beautify SQL queries |
| Word Counter | Count words, characters, sentences |
| CSS Gradient Generator | Create CSS gradients visually |
| Lorem Ipsum Generator | Generate placeholder text |
| Chmod Calculator | Calculate Unix file permissions |
| HTML Entity Encoder | Encode/decode HTML entities |
| Text Case Converter | Convert text between cases |
| JSON/CSV Converter | Convert between JSON and CSV |
| Number Base Converter | Convert between binary, octal, decimal, hex |
| Meta Tag Generator | Generate Open Graph and Twitter Card tags |
| CSS Box Shadow Generator | Create CSS box shadows with live preview |
- 100% client-side — your data never leaves the browser
- No signup, no ads — just tools
- Fast — static site, no server round-trips
- Open source — contribute or fork
MIT