Free Developer Tools Online

Free online developer tools: JSON formatter, regex tester, Base64 encoder, hash generator, markdown editor, and more.

Developer

JSON Formatter

Format, beautify, minify, and validate JSON data instantly. Free online JSON formatter with syntax highlighting.

Try Now

Developer

Base64 Encoder

Encode text to Base64 or decode Base64 strings instantly. Free, fast, and works entirely in your browser.

Try Now

Developer

Markdown Previewer

Write Markdown and see a real-time preview side by side. Supports headings, bold, italic, links, lists, code, and more.

Try Now

Developer

Timestamp Converter

Convert Unix timestamps to human-readable dates and vice versa. Shows UTC, ISO 8601, local time, and relative time.

Try Now

Developer

Regex Tester

Test and debug regular expressions with real-time matching, highlighting, and match details. Includes common presets.

Try Now

Developer

Text Diff Checker

Compare two texts side by side and see additions, removals, and changes highlighted. Free online diff tool.

Try Now

Developer

Image to Base64

Convert any image to a Base64 data URI string for embedding directly in HTML, CSS, or JSON. No server upload needed.

Try Now

About Our Free Developer Tools

Speed up your development workflow with our browser-based dev tools. The JSON formatter beautifies, minifies, and validates JSON with clear error messages and syntax highlighting. The regex tester provides real-time pattern matching with highlighted results and preset patterns for common use cases (email, URL, phone). The Base64 encoder/decoder converts text and binary data for APIs, data URIs, and email attachments. The hash generator uses the Web Crypto API to create SHA-256, SHA-384, SHA-512, and SHA-1 hashes without any server round-trip. The markdown previewer shows live HTML output as you type. The Unix timestamp converter translates epoch times to human-readable dates in UTC, ISO 8601, and local formats.