How to compare two texts
Paste the original version into the left box and the changed version into the right box. The comparison runs automatically and appears underneath. Lines that were removed from the original are shown in red with a minus sign; lines added in the new version are shown in green with a plus sign; unchanged lines are shown without a marker. A summary above the result counts the added, removed and unchanged lines.
Options
- Ignore case treats lines that differ only in capitalization as identical.
- Ignore whitespace ignores differences in spacing, indentation and trailing spaces, so you only see real content changes.
- Show only changes hides unchanged lines and shows how many were skipped, which makes long documents easier to scan.
Use Swap sides if you pasted the versions the wrong way round.
How the comparison works
The checker compares text line by line and finds the longest sequence of lines the two versions have in common. Everything outside that shared sequence is marked as added or removed. When a line is edited, it appears as the old line removed followed by the new line added. For the clearest results with prose, put each sentence or paragraph on its own line.
Common uses
Checking what an editor or client changed in a draft, comparing two versions of a contract clause, spotting changes between an old and new robots.txt or config file, reviewing edits to a page's copy before and after an update, and comparing two keyword or URL lists are all quick jobs with a diff checker. Because everything runs in your browser, it's safe for confidential documents.
Frequently asked questions
Is my text uploaded to a server?
No. The comparison runs completely in your browser, so it's safe to use with private or confidential documents.
Can it compare Word documents or PDFs?
Copy the text out of each document and paste it into the two boxes. Formatting is ignored; only the text is compared.
Why is an edited line shown twice?
The checker works line by line. When a line changes, the old version is shown as removed and the new version as added, right next to each other.
Is there a size limit?
Very large documents that are also very different may be too big to compare in the browser. In that case, compare them section by section.
Last updated