Compare two blocks of text and see the differences highlighted line by line. Everything runs in your browser.
Paste text into both fields and click Compare.
This diff checker lets you compare two blocks of text and instantly see what has changed. Whether you are reviewing code edits, checking document revisions, or verifying configuration file updates, this tool highlights every addition, deletion, and unchanged line in a clear, colour-coded view.
The tool uses a longest common subsequence (LCS) algorithm to compute the minimal set of differences between your original and modified text. Each line is classified as added, removed, or unchanged. Added lines appear with a green background and a plus prefix, removed lines show a red background with a minus prefix, and unchanged lines remain neutral. A stats bar summarises the total count of each type so you can quickly gauge the scope of changes.
Developers frequently use diff checkers to review pull requests, compare configuration files, or debug unexpected changes in generated output. Writers and editors find them useful for tracking revisions between drafts of an article or document. System administrators compare server configurations before and after deployments. Students can use the tool to see exactly what their tutor changed in returned feedback.
Everything runs entirely in your browser. No text is sent to any server, which means your data stays private. The comparison happens instantly regardless of text length, and there is no file size limit beyond what your browser can handle. No account or sign-up is required. Simply paste your text, click Compare, and see the results immediately.
ectoplasma.org · Free tools for everyone.