Code Syntax Highlighter

The Code Syntax Highlighter colourises code in dozens of languages and lets you copy it as styled HTML, right in your browser.

Paste your code, and it is highlighted instantly. Copy the HTML to drop formatted code into a blog or docs.

How to highlight code

1. Pick a language. Or leave it on auto-detect.
2. Paste your code. The highlighted result appears as you type.
3. Copy it. Grab the styled HTML, or the plain code.

From plain text to readable code

Unhighlighted code is a wall of one colour that is slow to scan. Highlighting separates keywords, strings, and comments so the structure jumps out.

Because everything runs locally, you can highlight private code without sending it anywhere, and paste the result wherever you publish.

• Private: highlighting runs on your device, never uploaded.
• Many languages: dozens supported, with auto-detect.
• Copy as HTML: paste formatted code into any page.
• Instant: updates live as you edit.

Related code tools

Highlighting reads best on clean code. To tidy a minified snippet first, the JS & CSS Beautifier reindents JavaScript and CSS.

If you are pasting code into HTML by hand, the HTML Entity Converter escapes the special characters safely. And to render fenced code blocks from a document, the Markdown to HTML Converter turns Markdown into HTML.

Frequently Asked Questions

Is my code uploaded to highlight it?

No. Highlighting happens entirely in your browser, so your code never leaves your device. Nothing is uploaded or stored.

Which languages are supported?

It supports dozens of common languages including JavaScript, TypeScript, Python, PHP, Java, C, C++, Go, Rust, SQL, HTML, CSS, JSON, YAML, and more.

What does \"copy as HTML\" do?

It copies the highlighted code as ready-to-paste HTML, with the colour styling included, so it appears formatted in a blog post, email, or document.

Does auto-detect always get the language right?

It is usually accurate, but for short snippets it can guess wrong. If the highlighting looks off, pick the language manually for the best result.

Can I use the output on my website?

Yes. The copied HTML uses standard highlight.js class names, so it works with any matching stylesheet, and the colours are inlined so it looks right on its own.