Text Diff Checker
Compare two pieces of text and see exactly what changed, line by line.
What is the Text Diff Checker?
This tool compares two blocks of text line by line and highlights exactly what changed: lines removed from the original are marked in red, lines added in the changed version are marked in green, and unchanged lines are shown as-is for context.
How to use it
- Paste the original text into the left box and the updated version into the right box.
- Click Compare to see a line-by-line breakdown of additions and removals.
This is useful for reviewing an edited contract or essay, comparing two versions of a configuration file, checking what changed between two exports of the same data, or spotting a typo fix buried in a larger block of text that would be tedious to compare by eye. The comparison works at the line level using a standard longest-common-subsequence approach, the same underlying idea used by tools like diff and Git — so a line that moved without changing is shown as unchanged, while a line with even a single character edited is shown as one removal and one addition. Everything runs locally in your browser; neither text is uploaded anywhere.
Want the "why" behind this tool? Read How a Diff Tool Decides What Actually Changed.