Compare in three steps
- Paste the earlier version into Original text and the newer version into Changed text in the Text Diff Checker.
- Choose whether to ignore differences in spacing or capitalisation.
- Select Compare texts. Removed lines are marked with a minus sign and a red background, added lines with a plus sign and a green background. Where a line was edited, the exact words that changed are highlighted inside it.
Common uses
- Contracts and agreements — confirm that only the clauses you discussed were changed.
- Articles and essays — see what an editor changed, or check a rewritten version.
- Website copy — compare old and new versions of a page before publishing.
- Configuration files and code — find the one setting that differs between two servers.
- Data — compare two exports; sort both lists first so the order does not create false differences.
Avoiding false differences
The comparison works line by line. If one version has paragraphs on a single line and the other wraps them every 70 characters, almost every line will appear changed even though the words are identical. Tick Ignore differences in spacing and, if needed, put each paragraph on one line in both versions before comparing.
When comparing JSON, format both documents the same way first with the JSON Formatter and Validator and sort the keys, so only real changes stand out.
Comparing Word and PDF documents
The checker compares plain text, so copy the text out of each document and paste it in. Formatting changes such as bold or font size will not appear. For Word files, Microsoft Word’s own Review → Compare feature shows formatting changes as well. Remember that a moved paragraph appears as a deletion in one place and an addition in another.
Sharing the result
Select download to save the comparison as a unified diff file, the standard format used by developers and version-control tools such as Git. Because the comparison runs in your browser, confidential documents are not uploaded anywhere.
Frequently asked questions
How long can the texts be?
Each side can have up to 20,000 lines, which covers most documents and code files.
Can it detect moved paragraphs?
Not separately. A moved block shows as removed from its old position and added at its new one.