Free Developer Tools Online

Last updated: April 2026

Free online developer tools for JSON, Base64, regex, hashing, and more.

FreeToolPark's developer tools help programmers format, encode, hash, validate, and convert data instantly in the browser. No installation, no API keys, no rate limits - just fast, reliable tools built for daily development workflows. All tools process data client-side so your code and data stay private.

JSON Formatter

Format, validate and beautify your JSON data instantly. Supports syntax highlighting, error detection, and minification. Free online tool - no signup required.

Base64 Encoder/Decoder

Encode text to Base64 or decode Base64 to text instantly. Supports UTF-8. Free online Base64 encoder and decoder - no signup required.

Regex Tester

Test regular expressions with real-time highlighting, match details, and capture groups. Free online regex tester - no signup required.

Color Picker

Pick colors and convert between HEX, RGB, and HSL formats instantly. Free online color picker with visual preview - no signup required.

UUID Generator

Generate random UUID v4 identifiers instantly. Bulk generation, uppercase, and hyphen options. Free UUID generator - no signup required.

MD5 Hash Generator

Generate MD5 hashes from any text instantly. Free online MD5 hash generator with one-click copy - no signup required.

URL Encoder/Decoder

Encode and decode URLs and query parameters instantly. Supports encodeURIComponent and encodeURI. Free online URL encoder/decoder.

SHA-256 Generator

Generate SHA-256 hashes from any text using the Web Crypto API. Free online SHA-256 hash generator - no signup required.

CSS Gradient Generator

Create beautiful CSS gradients with a visual editor. Supports linear, radial, and conic gradients. Copy CSS code instantly. Free online tool.

Timestamp Converter

Convert between Unix timestamps and human-readable dates. Live current timestamp, ISO 8601, and UTC formats. Free online timestamp converter.

HEX to RGB Converter

Convert HEX color codes to RGB and HSL values instantly. Free color converter with live preview, color picker, and one-click copy. Works both ways.

Markdown to HTML

Convert Markdown to clean HTML code instantly. Free Markdown to HTML converter with live preview, syntax highlighting, and one-click copy. No signup required.

CSS Minifier

Minify CSS code instantly to reduce file size and improve page speed. Free CSS minifier that removes comments, whitespace, and redundant code. One-click copy.

JavaScript Minifier

Minify JavaScript code to reduce file size and boost page speed. Free JS minifier that strips comments and whitespace. One-click copy for production use.

HTML Minifier

Minify HTML code to reduce page size and improve load times. Free HTML minifier removes comments, whitespace, and redundant tags. Copy minified HTML instantly.

Frequently Asked Questions

Do these dev tools send my data to a server?

No. Every tool on FreeToolPark runs entirely in your browser using JavaScript. No data is transmitted to any server. This makes them safe for sensitive code, API keys, and internal data.

Which developer tools are most popular?

The JSON Formatter, Base64 Encoder/Decoder, Regex Tester, and UUID Generator are the most widely used. These cover the most common daily developer needs for API debugging and data processing.

Can I use these tools offline?

Once the page loads, most tools will continue to work even if you lose internet connection, since all processing happens in your browser. Bookmark the tools you use most for quick access.