Text Diff Checker
Text Diff Checker is a free text tool that runs directly in your browser with no account required.
About this tool
Compare two blocks of text line by line and see additions, removals, and unchanged lines color-coded in a unified view. The diff uses a longest-common-subsequence algorithm, reports counts for each change type, and exports a patch-style file with +/- prefixes.
How to use
- Paste the first version into the Original text field.
- Paste the second version into the Changed text field.
- Review the Added, Removed, and Unchanged counts and the color-coded diff rows.
- Click Download diff to save a plain-text patch-style file.
Frequently asked questions
Does it compare by line, word, or character?
By line. Each line is matched whole, so a one-word edit shows the old line as removed and the new line as added. There is no intra-line word highlighting.
What algorithm drives the diff?
A longest-common-subsequence (LCS) comparison, the same family of algorithm used by classic diff tools, which finds the minimal set of added and removed lines.
Is the downloaded file a real git patch?
It is a readable patch-style text file where lines are prefixed with +, -, or a space. It has no file headers or hunk markers, so it documents changes but is not directly applyable with git apply.
Is whitespace significant in the comparison?
Yes. Lines must match exactly, so indentation or trailing-space differences register as changes. Normalize both texts with the Whitespace Remover first if that noise is unwanted.
Can I diff confidential documents here?
Yes. Both texts are compared locally in your browser and are never uploaded, so contracts or internal drafts stay private.