Text Diff Checker
Paste two versions of text to instantly see what changed. Added lines in green, removed in red — free, browser-based, no upload.
■ Removed lines
■ Unchanged
What is a Text Diff Checker?
A text diff checker compares two versions of text and highlights the differences — added lines in green and removed lines in red. This is the same concept used by Git, GitHub, and code review tools to show changes between file versions.
Common Use Cases
- Compare two versions of a document or contract
- Find changes between original and edited articles
- Spot differences in configuration files or code snippets
- Verify that only intended changes were made to a file
How the Diff Algorithm Works
This tool uses the Longest Common Subsequence (LCS) algorithm to find the maximum set of lines shared between both texts. Lines that appear in the original but not the modified text are marked as removed; lines that appear in the modified text but not the original are marked as added.
Frequently Asked Questions
Is there a limit on text size?
For performance reasons, the diff is limited to approximately 500 lines per text block. For larger files, use a dedicated diff tool such as Git’s git diff command.
Does this compare character-by-character or line-by-line?
This tool compares line by line. Each line is treated as a unit — if even one character differs, the entire line is marked as changed.