Diff Checker
Compare two texts side by side.
Loading tool
Paste an old version and a new version. Changed lines are marked so you can review a copy edit.
How to use this tool
- Paste your text. Put the draft or list into the field at the top of this page. Nothing is uploaded.
- Adjust the options. Pick the mode or flags you need. Results update in this tab.
- Copy the result. Use Copy when the output looks right. Refreshing the page clears the text.
How it works
A line-level Myers-style diff. Whitespace-only changes can be ignored. It is not a git binary diff.
Frequently asked
Can I compare files?
Open the files, paste the contents. Nothing is uploaded.
Is this unified diff format?
The view is side by side. You can copy a unified patch if you want.
Are moves detected?
A moved block looks like a delete plus an add.
Is there a size limit?
Very large files may feel slow in the browser. Split them.
Is my text stored?
No.