Diff Checker
Find differences between two texts
Compare two versions of any text — code, config, prose, logs — and see additions and removals highlighted line by line. No sign-up, no file uploads, no history retained.
When a diff tool earns its keep
You spot an unexpected behavior in production. The "only change" between two deploys is a config file someone edited. You need to see exactly what changed, now, before opening the full git client. Or you have two versions of a contract clause a colleague emailed you. Or two nearly-identical error logs from different services. A diff tool turns "spot the difference" from a slow, error-prone eyeball task into a ten-second reading job.
How to read the diff output
- Green lines marked + are additions present in the modified version but not the original.
- Red lines marked − (and shown struck through) are deletions present in the original but removed in the modified version.
- Unmarked lines are identical in both versions.
- The counter at the top of the Differences panel shows totals at a glance.
Line-based diffing: limits to know
This tool compares line by line. If you change a single word within a long line, the whole line is shown as removed and re-added. That is standard behavior for most diff tools and is what git uses by default. For word-level or character-level diffing — useful in prose — dedicated tools exist but produce noisier output for code.
Frequently asked questions
Can I diff more than two files?
Not in a single view. For three-way diffs (common during merge conflicts), a desktop tool like Beyond Compare, Meld, or your git client is more suitable.
Is my text saved anywhere?
No. Both inputs stay in your browser tab. Closing or refreshing the page discards them. Nothing is uploaded.
Does it handle very long files?
Up to a few thousand lines works comfortably. Tens of thousands will make the browser sluggish — at that point, use a desktop diff tool.