HTML Diff & Compare
Paste two HTML documents to see highlighted line-by-line differences, a change summary, and a similarity percentage. Everything is processed on your device.
Everything runs in your browser. Your data is never sent to our servers.
Example
Example Input
two HTML templates
Example Output
changed markup highlighted
How to Use
- 1Paste the first HTML documents (A) in the left box and the second (B) in the right box.
- 2Adjust the options if needed (ignore case, whitespace, or empty lines).
- 3Click Compare (or press Ctrl+Enter).
- 4See the highlighted differences, a summary of how many changes there are, and the similarity percentage. Switch between side-by-side / unified / inline views.
About HTML Diff & Compare
HTML Diff & Compare compares two pieces of HTML markup line by line and highlights changes. Useful for reviewing changes to templates, emails, or pages.
For a structural comparison (the DOM tree, not raw text), use DOM Diff, which parses the markup into an element tree.
FAQ
What is the difference between "diff" and "compare"?
Both are done by the same tool. "Diff" highlights the lines/parts that changed (added/removed), while "compare" shows how similar the two inputs are (similarity percentage + summary). You get both at once here.
Is my data sent to a server?
No. The entire comparison is computed in your browser with JavaScript. Nothing is uploaded, logged, or stored on our servers — safe for sensitive data.