How to compare two texts
- Paste the original version on the left and the changed version on the right — the diff renders live below.
- Red lines with
-were removed, green lines with+were added, plain lines are unchanged. - Toggle Ignore whitespace or Ignore case to filter out noise like re-indentation.
When a diff beats rereading
Eyeballing two versions of anything — a contract clause, a config file, an essay draft, an AI-edited rewrite — is how subtle changes slip through. A line diff makes every change explicit and impossible to miss. It's the same algorithm behind git diff: find the longest sequence of lines the two texts share, and everything outside it is an addition or removal. Because this tool runs entirely on your device, it's safe for the comparisons you'd never paste into a random website: legal documents, source code, credentials-laden configs, unpublished writing.
Frequently asked questions
How does the diff checker compare texts?
Line by line, using the same longest-common-subsequence approach as git and classic diff tools. Removed lines show red with a minus, added lines green with a plus.
Can I ignore whitespace or capitalization differences?
Yes — Ignore whitespace treats lines differing only in spacing or indentation as identical; Ignore case treats Hello and hello as the same.
Is it safe to paste confidential documents?
Yes. The comparison runs entirely in your browser — nothing you paste is transmitted, logged or stored anywhere.
How large can the texts be?
Around 2,000 lines per side compares instantly. Beyond that the tool asks you to trim rather than freeze your tab.