Compare Text
Paste two texts and see line-level differences side by side — green for added lines, red for removed.
How to use
- Paste the original text on the left, the changed one on the right.
- Press Compare — changed lines pair up red/green between the panes.
- Read the summary line for counts, then Clear to start over.
Frequently asked questions
How does the comparison work?
A line-level longest-common-subsequence diff: lines present in both texts are matched in order, and anything skipped is marked as removed (left, red) or added (right, green). Matching blocks are aligned side by side so changes read as paired rows.
How large can the texts be?
Up to 3,000 lines per side for a precise diff — beyond that the tool tells you it fell back to a whole-block comparison instead of pretending to be exact. Common prefix and suffix lines are trimmed first, which keeps typical document edits fast.
Why does a changed line show as one red and one green row?
A plain LCS diff has no concept of "changed" — the old line is removed and the new one is added. Reading the adjacent red/green pair as a change is exactly how professional diff tools display it too.
Do blank lines matter?
Yes, blank lines take part in the diff like any other line. An empty first field is treated as zero lines, so comparing empty text against something shows a pure addition.
Is my text stored or sent anywhere?
No. Both panes live only in your browser tab; comparing, clearing or reloading wipes them completely.