9 Free Code Tools
Format JSON, Minify HTML/CSS/JS & Test Regex
Format JSON, minify HTML, CSS and JavaScript, test regular expressions, and compare code differences. Everything runs in your browser so you can work offline and keep sensitive code private.
Code Tools
Base64 Encoder/Decoder
Encode text, files, and images to Base64 or decode Base64 strings back to files. Generate data URIs for HTML and CSS embedding. Free Base64 encoder and decoder, 100% private.
Code Beautifier
Beautify and format code for multiple languages. Transform minified or messy code into clean, readable format instantly.
Code Diff Checker
Compare code changes side by side with syntax highlighting. Instantly see additions, deletions, and modifications between two code versions.
CSS Minifier
Minify CSS files to reduce size by up to 70%. Improve page load speed and website performance. Fast, secure, and completely free.
HTML Entity Encoder
Encode and decode HTML entities instantly. Convert special characters for safe HTML display and prevent XSS attacks.
HTML/CSS/JS Minifier
Minify or beautify HTML, CSS, and JavaScript code. Reduce file size by up to 80% or format code for better readability.
JSON Formatter & Validator
Format, validate, and beautify JSON data instantly. Perfect for developers working with APIs and data structures. Fast, secure, and free.
Markdown to HTML Converter
Convert Markdown to clean HTML instantly. Perfect for documentation, blogs, README files, and content creation with live preview.
Regex Tester & Debugger
Test and debug regular expressions with live matching, syntax highlighting, and detailed explanations. Perfect for developers learning regex.
9 Free Code Tools That Run Entirely in Your Browser
All 9 code tools run entirely in your browser using client-side JavaScript. Your code never leaves your device -- which matters when you are working with API keys, environment configs, or proprietary logic that should not be pasted into random third-party servers.
The JSON Formatter & Validator is the most-used tool here. Paste raw API responses, minified config files, or hand-written JSON and get a clean, indented view with syntax highlighting. Errors are flagged with line numbers so you can fix them quickly. The Code Diff Checker puts two versions side by side and highlights exactly what changed -- useful for reviewing edits or spotting unintended modifications.
The HTML/CSS/JS Minifier strips whitespace and comments before you push to production. The Code Beautifier reverses that -- it reformats minified code into readable output so you can audit or edit it. The Regex Tester lets you write and test regular expressions against real input with match highlighting, without switching apps or writing throwaway test scripts.
Additional tools include a CSS Minifier, HTML Entity Encoder/Decoder, Markdown to HTML Converter, and Base64 Encoder/Decoder. Whether you are prepping files for deployment, debugging API output, or trying to understand a regex pattern, each tool gives you results in seconds with no installs and no sign-up required.
All tools run entirely in your browser. No files are uploaded to our server.
Explore Other Categories
Discover more tools for different needs
Image Tools
Compress, convert, and optimize images for blazing-fast websites. All processing happens securely in your browser.
Design Tools
Create stunning gradients, perfect color palettes, and test contrast. Built for designers who care about details.
SEO Tools
Optimize meta tags, preview search results, generate QR codes, and boost your search rankings.
Converters
Convert between formats instantly. JSON to CSV, timestamps, color codes, units, and Base64 encoding.
HTML & CSS Generators
Generate CSS code visually. Gradients, box shadows, flexbox, grid layouts with live preview and copy-ready code.
Text Tools
Manipulate text easily. Case converter, word counter, slug generator, and lorem ipsum placeholder text.
Security Tools
Generate secure passwords, create cryptographic hashes, produce unique UUIDs, and decode JWT tokens.
Web Utilities
Essential web tools for developers. IP lookup, user agent parser, HTTP status codes reference, and query string builder.
PDF Tools
Merge, split, compress, convert, and edit PDF files - all inside your browser. No uploads, no installs, 100% free.
Frequently Asked Questions
Everything you need to know
Our code tools support JSON, HTML, CSS, JavaScript, XML, and SQL. You can format, minify, validate, and compare code across all these languages.
No. All code formatting, minification, and validation happens locally in your browser using JavaScript. Your code never leaves your device.
Yes. Once the tool page loads, all processing is done client-side using JavaScript. The tools work even if your internet connection drops mid-session.
Paste your CSS or JavaScript into our minifier tool. It removes whitespace, comments, and shortens variable names where possible, giving you production-ready minified code in seconds.
The JSON formatter takes raw or minified JSON and formats it with proper indentation, line breaks, and syntax highlighting. It also validates the JSON and highlights any syntax errors with line numbers.
Beautifying (also called formatting or pretty-printing) adds indentation, line breaks, and spacing to make code readable. Minifying does the opposite -- it strips all whitespace, comments, and shortens identifiers to reduce file size. Beautify code during development for readability; minify it before deploying to production for faster page load times.
Yes. The Code Diff Checker works with any plain text input -- XML documents, SQL scripts, config files, or prose. It highlights line-level and word-level differences side by side regardless of file type. The Code Beautifier also supports multiple languages beyond HTML, CSS, and JS.
Base64 encoding converts binary data -- like images or files -- into a text string that can be safely embedded in HTML, CSS, JSON, or transmitted over text-based protocols. Use the decoder to reverse that process and get back the original data. Common uses include embedding small images directly in CSS as data URIs and encoding auth tokens.
Paste any Markdown text and the converter renders it as HTML with a live preview. It supports GitHub Flavored Markdown including headers, lists, tables, code blocks with syntax highlighting, bold, italic, and links. Copy the raw HTML output to use in a CMS, email template, or web page.
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