70 toolsAbout Text Compare
Text Compare is a free online tool that shows you exactly what changed between two pieces of text. Paste your original text on the left and the modified version on the right, then click Compare. Every added line is highlighted in green, every removed line in red, and changed lines in yellow with word-level highlights so you can pinpoint the exact words that differ.
This text comparison tool is useful for comparing document revisions, proofreading edits, reviewing configuration file changes, checking code differences, comparing data exports, and spotting changes in any kind of content.
The tool uses the longest common subsequence (LCS) algorithm — the same approach used by Git and Unix diff — to produce the most accurate, minimal set of changes. Word-level diff is enabled by default so modified lines show precisely which words changed, not just which lines.
Everything runs locally in your browser. Your text is never uploaded or stored on any server.
How to Use Text Compare
Paste the original text in the left panel.
Paste the modified or updated text in the right panel.
Click Compare — differences are highlighted instantly.
Green highlights show added text, red shows removed text, yellow shows modified lines with word-level changes pinpointed.
Frequently Asked Questions
What is a text compare tool?
A text compare tool (also called a diff checker) takes two pieces of text and highlights exactly what changed between them — which lines were added, removed, or modified. It saves you from manually reading both versions to spot differences.
Does it compare word by word or line by line?
Both. The tool first compares line by line to find which lines changed, then within each changed line it highlights the exact words that differ. You can switch between Word diff and Line diff modes using the toggle in the results toolbar.
Can I use this to compare code?
Yes — paste code from any language into the two panels and differences are highlighted immediately. The monospace font and line-by-line comparison make it easy to review code changes.
What algorithm does the text comparison use?
The longest common subsequence (LCS) algorithm, which is the same approach used by Git, GitHub, and Unix diff. It finds the minimal set of changes needed to transform one text into the other.
Can I compare two versions of a document?
Yes — paste the old version on the left and the new version on the right to see every change highlighted. This works for any text content: articles, emails, contracts, config files, and more.
Is there a size limit?
No hard limit. The tool handles large texts in your browser, though very large files (100,000+ lines) may slow down the comparison.