What programming languages does this code formatter support?

This code formatter and syntax highlighter supports 14+ popular programming languages including JavaScript, TypeScript, Python, HTML, CSS, JSON, Java, C++, Ruby, Go, Rust, SQL, Bash, and PHP. Each language gets proper syntax highlighting with color-coding for keywords, strings, comments, functions, and other language constructs. The highlighting engine uses Highlight.js library, which recognizes language-specific syntax patterns and applies appropriate styling. Simply select your language from the dropdown menu, paste your code, and see it instantly highlighted with professional formatting. This makes the tool perfect for creating code examples for documentation, blog posts, presentations, or sharing code snippets with colleagues.

How do I use this tool to format and highlight my code?

Using the code formatter is simple: first, select your programming language from the dropdown menu. Second, paste or type your code into the input textarea. The tool automatically applies syntax highlighting in real-time as you type, color-coding keywords, strings, variables, functions, and comments based on the selected language. Third, view the formatted, highlighted code in the preview panel with proper color schemes. Finally, click "Copy Code" to copy the highlighted HTML to your clipboard for use in web pages, or copy the plain code for other purposes. You can also use the sample code provided for each language to see how the highlighting works before pasting your own code.

Can I customize the color scheme or syntax highlighting theme?

Currently, the tool uses the GitHub Dark theme from Highlight.js, which provides a professional dark background with carefully chosen syntax colors optimized for readability. This theme features distinct colors for keywords (purple/blue), strings (green), comments (gray), functions (yellow), and other syntax elements. The GitHub Dark theme is widely recognized and preferred by developers for its excellent contrast and eye-friendly color palette. While custom theme selection is not currently available in this version, the default theme works well for most use cases including documentation, presentations, and code sharing. The consistent styling ensures your code examples look professional and are easy to read across different contexts.

Does the code formatter actually reformat or beautify my code structure?

This tool is primarily a syntax highlighter that adds color-coding to your code—it does not restructure, reformat, or beautify the code itself. The tool preserves your original formatting, indentation, spacing, and line breaks exactly as you provide them. If you paste minified or poorly formatted code, it will highlight the syntax but won't add proper indentation or restructure the code. For code beautification (auto-indentation, line breaking, etc.), you would need a dedicated code formatter like Prettier for JavaScript, Black for Python, or language-specific formatters. This tool focuses on making your existing code more readable through color syntax highlighting, which is perfect for sharing code snippets, creating documentation, or preparing code for presentations where visual clarity matters.

How can I use the highlighted code in my blog or documentation?

After highlighting your code, click the "Copy Code" button to copy the formatted output. The tool provides syntax-highlighted code that you can embed in various contexts. For websites or blogs, the copied output includes HTML with inline styles or CSS classes that preserve the syntax highlighting. You can paste this directly into HTML editors, content management systems like WordPress, or static site generators. For Markdown-based documentation (like GitHub README files), you can use the plain code with language-specific fencing (triple backticks with language identifier) to get syntax highlighting. Many platforms like GitHub, GitLab, and documentation tools automatically apply syntax highlighting to fenced code blocks, so you may only need the plain code with proper language tags rather than pre-highlighted HTML.

Does this tool work offline, or do I need an internet connection?

After the initial page load, the code formatter works completely offline using browser caching. The Highlight.js library is loaded once and cached locally, allowing you to format and highlight code without an active internet connection. This makes the tool useful for developers working in environments with limited connectivity or those who prefer privacy (your code never leaves your browser or gets sent to any server). All processing happens client-side in your browser using JavaScript. However, you need an internet connection for the first visit to load the tool and highlighting library. Once loaded, you can bookmark the page and use it offline. Your code is processed locally and remains completely private.

Can I highlight code snippets for multiple languages on the same page?

While this tool highlights one code snippet at a time with a single language selection, you can easily process multiple snippets sequentially. Change the language dropdown to match each snippet you want to highlight, paste the code, copy the highlighted result, and repeat for your next snippet in a different language. For documentation or blog posts with multiple code examples in different languages, this workflow lets you generate properly highlighted code for each language. If you're building a documentation site or blog with many code examples, consider using a static site generator (like Next.js, Gatsby, or Hugo) with built-in syntax highlighting plugins that automatically detect and highlight all code blocks in various languages across your entire site.

Why does my code show different colors than in my code editor?

Different syntax highlighting themes and engines use different color schemes based on their design philosophy and tokenization rules. Your code editor (like VS Code, Sublime Text, or JetBrains IDEs) uses its own themes and syntax parsers, which may categorize and color code elements differently than Highlight.js. For example, one theme might color all function calls blue while another uses yellow. These are stylistic choices, not correctness issues. The important thing is that syntax highlighting improves readability by visually distinguishing different code elements. This tool uses the GitHub Dark theme for its professional appearance and wide recognition. If you prefer matching your editor theme exactly, you'd need to export code with your editor's specific theme or customize the CSS of this tool.

Can I use this tool to format and highlight JSON data?

Yes! Select "JSON" from the language dropdown and paste your JSON data. The tool will apply syntax highlighting to make the structure more readable, with different colors for keys, values, strings, numbers, booleans, and null values. This is helpful for debugging API responses, configuration files, or any JSON data. However, like with other languages, this tool only highlights syntax—it doesn't reformat or prettify the JSON structure. If you have minified JSON on a single line, paste it into a JSON formatter first to add proper indentation and line breaks, then use this tool for syntax highlighting. For JSON-specific needs like validation, minification, or tree views, consider using dedicated JSON tools alongside this syntax highlighter.

Is the syntax highlighting accurate for all edge cases and language features?

This tool uses Highlight.js, a mature and widely-used syntax highlighting library that handles the vast majority of common syntax correctly across all supported languages. However, no syntax highlighter is 100% perfect for every edge case, especially with complex or ambiguous code, preprocessor directives, or very new language features. Highlight.js focuses on common patterns and may occasionally misclassify unusual syntax or advanced language-specific constructs. For typical code examples, documentation, and general use, the highlighting is highly accurate and reliable. If you notice highlighting issues with specific code, it's usually harmless (visual only) and doesn't affect the actual code—it only changes how elements are colored, not the code itself.

Free Code Formatter & Syntax Highlighter

Format and highlight code online with syntax highlighting for JavaScript, TypeScript, Python, HTML, CSS, JSON, and more. Real-time color-coded formatting. Perfect for documentation, presentations, and code sharing.

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