An edited sentence (by words)
The quick brown fox. vs The slow brown fox!: quick → slow and . → ! — 2 words added, 2 removed.
Text Difference Checker
Compare two texts and highlight what was added, removed or changed, line by line or word by word.
Runs in your browser — nothing you enter is sent to a server.
How the Text Difference Checker works
Paste the original and the changed version, then select Compare texts. Added text is marked with + and highlighted in green; removed text is marked with − and highlighted in red. Choose Lines for documents, lists and code, or Words to see exactly which words changed inside a paragraph.
The comparison uses the Myers diff algorithm — the same approach as git diff — which finds the smallest set of additions and deletions that turns one text into the other. Both texts stay in your browser; nothing is uploaded, so it's safe for contracts, drafts and private code.
Examples
A changed list (by lines)
one, two, three vs one, 2, three, four (one per line): 2 lines added, 1 removed, 2 unchanged.
Frequently asked questions
Why does a changed line show as removed and added?
In line mode, a line is the smallest unit: any change inside it removes the old line and adds the new one. Switch to Words to see the exact change within the line.
Can it ignore case or spacing?
Yes. Ignore case treats “Hello” and “hello” as equal; Ignore spacing ignores extra, leading and trailing spaces. Unchanged parts are shown as they appear in the changed text.
Is there a size limit?
Long texts are fine when they are mostly similar. If the two versions differ in more than 2,000 places, the tool asks you to compare smaller sections, so your browser stays responsive.
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Also in Tools for Students and Tools for Writers.