JSON Syntax Highlighter
Turn JSON into color-highlighted HTML.
JSON Syntax Highlighter – Colorful JSON as HTML
The JSON syntax highlighter converts JSON into a self-contained HTML snippet with colored keys, strings, numbers, booleans, and null values. Copy it into a blog post, documentation page, README rendered as HTML, or email, and your JSON examples look like they came out of a code editor.
How it works
- Paste your JSON (minified or formatted).
- Choose a theme: GitHub light, VS Code dark, or Monokai. Turn on line numbers if you like.
- The HTML code appears on the right and a live preview is rendered below.
- Copy or download the HTML and paste it wherever you need it.
The JSON is validated and pretty-printed first, so even a one-line API response becomes a nicely indented, readable example.
Why inline styles?
Most syntax highlighters need a CSS file and a JavaScript library on the page. That's not possible in many CMS editors, newsletters, or knowledge bases. This tool writes the colors directly into each <span style="color:…">, and the <pre> element carries its own background and monospace font. No dependencies, no build step — it just works.
Security
All text is HTML-escaped: <, >, & and quotes become entities. JSON containing markup or scripts is displayed literally and can't inject anything into your page. The preview itself is rendered in a sandboxed frame.
Related tools
To render JSON as a table instead, use JSON to HTML. For interactive exploration, open the JSON Viewer, and to prepare the JSON first, try the JSON Beautifier.
Frequently Asked Questions
Will the highlighted code work without extra CSS or JavaScript?
Yes. Colors are written as inline styles on each <span>, and the <pre> block carries its own background, font, and padding. Paste it into any HTML page, CMS, or email template and it looks the same.
Is it safe to paste JSON with HTML in it?
Yes. Characters like <, >, &, and quotes are escaped as HTML entities, so strings such as "<script>" are displayed as text and never executed.
Can I use it in WordPress or Medium?
In WordPress, use a Custom HTML block and paste the output. Platforms that strip inline styles (such as Medium) will show the text without colors; for those, a screenshot of the preview is the usual workaround.
Do line numbers get copied along with the code?
In the preview they're marked as non-selectable, so readers copying the code from your page won't pick them up in most browsers.