TXTCompare two texts and highlight every change.
Diff Checker compares two versions of a text word by word and highlights the differences inline: additions in green, deletions in red strikethrough, unchanged text plain. Paste the original on the left and the edited version on the right, then click Compare. It all runs on your device.
Paste the original text into the left box and the changed version into the right box.
Click Compare. The two texts are diffed word by word in your browser.
Read the result below: green marks words that were added, red strikethrough marks words that were removed.
This tool requires a Pro subscription. The comparison itself happens on your device.
It runs a word-level diff based on the longest common subsequence, the same idea code-review tools use. Words present only in the changed text show as added, words present only in the original show as removed, and everything else stays plain.
Yes. Each text can be up to roughly 6,000 words so the comparison stays fast on your device. If either side is longer, you'll see a message asking you to shorten it; splitting a long document into sections works well.
No. The diff is computed on your device, so both texts stay with you.
Last updated: July 8, 2026