10 Free Online Tools Every Developer Should Know

As a developer, you need reliable tools that work fast and respect your privacy. Here are 10 free tools every developer should bookmark:

1. JSON Formatter & Validator

Debug APIs, format messy JSON, and validate your data structures in seconds. Our tool highlights syntax errors and prettifies output with proper indentation.

2. Base64 Encoder/Decoder

Encode binary data for APIs, decode tokens, and work with data URIs. Essential for authentication and data transfer.

3. JWT Decoder

Inspect JSON Web Tokens without sending them to a server. Decode headers, payloads, and verify signatures locally in your browser.

4. HTML & URL Encoder/Decoder

Sanitize user input, encode parameters for URLs, and decode HTML entities. Perfect for form handling and XSS prevention.

5. Image Converter

Convert between PNG, JPG, WebP, GIF, BMP, and ICO formats instantly. No uploads needed — everything runs in your browser.

6. UUID Generator

Generate UUID v4 identifiers for database keys, API resources, and distributed systems. Batch generate up to 100 at once.

7. Markdown Editor

Write documentation with live preview. Supports headings, code blocks, tables, and more. Export as HTML when you're done.

8. Regex Tester

Test regular expressions against sample text in real-time. See matches, groups, and flags highlighted instantly.

9. Password Generator

Create strong, secure passwords with customizable length and character sets. Check password strength before saving.

10. Color Converter & Palette Generator

Convert between HEX, RGB, HSL, and generate harmonious color palettes for your projects. Perfect for designers and frontend developers.

All tools are 100% free, work offline in your browser, and never send your data to any server. Bookmark this page for quick access!