Text Diff Checker

Compare two text blocks and show what changed.

text-diff-checker.local
Paste text on both sides to see what changed.

How to use it

  1. Paste the original text on the left.
  2. Paste the changed text on the right.
  3. Read the highlighted added and removed lines.

About this tool

The text diff checker compares two blocks line by line using a longest common subsequence, then highlights lines that were added or removed. It is a line level diff, so a small change inside a line marks the whole line as changed rather than the exact characters. For performance it compares up to 1500 lines per side.

Examples

InputTwo versions of a list
OutputAdded lines in green, removed lines in red
InputA paragraph with one edited line
OutputThat line shown as removed then added

Common uses

  • Compare two versions of a note or config
  • Spot changes between drafts
  • Check what a paste changed
  • Review edits line by line

FAQ

Is my text uploaded?
No. The comparison runs in your browser. Nothing you paste is sent anywhere.
Is it a character or line diff?
Line level. A change anywhere in a line marks the whole line as removed and added, rather than the exact characters.
Is there a size limit?
Yes. It compares up to 1500 lines per side to keep the comparison fast in the browser.

Related tools

Embed this tool

Paste this snippet to put the tool on your own site. It runs entirely in the visitor's browser, the same as it does here.

<iframe src="https://tooldok.com/embed/text-diff-checker/" title="Text Diff Checker by Tooldok" width="100%" height="560" style="border:1px solid #16130d;border-radius:16px;max-width:720px" loading="lazy"></iframe> <p style="font:13px sans-serif"><a href="https://tooldok.com/tools/text-diff-checker/" target="_blank" rel="noopener">Text Diff Checker</a> by <a href="https://tooldok.com/" target="_blank" rel="noopener">Tooldok</a></p>