Text Diff Checker
Paste two versions of a text and see added lines in green and removed lines in red, with counts.
What is the Text Diff Checker?
A diff checker compares two versions of a text and shows exactly what changed: lines that were added appear in green and lines that were removed appear in red. It is the quickest way to spot an edit in a document, a contract, a draft or a piece of code.
The comparison is line by line, using the same longest-common-subsequence method as professional diff tools, and it runs entirely in your browser — your text is never uploaded.
How to use the Text Diff Checker
- Paste the original text in the first box.
- Paste the changed text in the second box.
- Press Compare.
- Read the colour-coded lines and the added/removed counts.
Key features
- Line-by-line diff with green/red highlighting
- Added and removed line counts
- Handles large texts with a fast fallback
- Great for documents, drafts and code
- 100% private — text never leaves your device
Frequently asked questions
How does the diff checker compare texts?
It compares the two texts line by line using a longest-common-subsequence algorithm: lines only in the second text are shown as added (green), lines only in the first as removed (red).
What is it useful for?
Checking edits to documents and contracts, reviewing code changes, comparing two drafts of an essay, or verifying that a copied text matches the original.
Is there a size limit?
It comfortably handles documents of a few thousand lines. Extremely large files may take a few seconds on a phone.
Is my text uploaded?
No. The comparison runs entirely in your browser — both texts stay on your device.