Compare text
Paste the original and the new version. Changes show up as you type.
Runs in your browser. What you paste is not sent to a server or stored.
How to read the result
Lines only in the original are marked in red with a minus sign; lines only in the new version are green with a plus sign. When a line was edited rather than added or deleted, both versions sit next to each other and the exact words that changed are highlighted, so a one-word edit in a long paragraph is easy to spot. The numbers at the edge are line numbers in each text.
The summary above the result counts lines changed, added and removed. An edited line counts once as changed. Git and many other tools count the same edit as one line removed and one added, so their totals can look bigger.
What people compare
Two drafts of an essay or contract, to see what a colleague changed. A product description before and after an edit. Two lists, such as email addresses or order numbers, to find the ones missing from one of them. Code or configuration files, where a single changed character matters. For lists, turn on Ignore case and Ignore extra spaces so "Apple" and " apple" count as the same line. When an edit has to stay under a word or character limit, check the new version with the character counter.
Examples
Each row is a real pair of texts and the summary line the tool shows for it. Lines are separated by a slash here to fit the table.
| Original | New version | Summary |
|---|---|---|
| Milk / Eggs / Bread / Apples / Coffee | Milk / Eggs / Brown bread / Apples / Coffee / Rice | 1 line changed · 1 line added |
| Anna / Ben / Carlos / Diana / Ethan | Anna / Carlos / Diana / Ethan / Fiona / George | 2 lines added · 1 line removed |
| Rent is due on the 1st of each month. / Late fees are $25. / The lease ends on June 30, 2027. | Rent is due on the 5th of each month. / The lease ends on June 30, 2027. | 1 line changed · 1 line removed |
| apple / Banana / cherry (with a space at the end) | Apple / banana / cherry | 3 lines changed, or "The two texts are the same." with both Ignore options on |
In the lease example, the edited rent line sits side by side with only "1st" and "5th" highlighted, and the late-fee line is marked as removed. That is the kind of change that is easy to miss when you read two versions of a contract one after the other. The last row shows why the Ignore options matter for lists: without them, a capital letter or a trailing space makes a line count as changed.
How the comparison works
The tool uses the Myers difference algorithm, the method behind Git and the Unix diff command. It finds the smallest set of lines to remove and add to turn the original into the new version, then compares the words inside each edited line the same way. Because it looks for the shortest list of changes, moved paragraphs show up as one removal and one addition rather than as many small edits.
Questions
Is there a size limit?
Texts with tens of thousands of lines work. If two very large texts have almost nothing in common, the tool stops searching for small edits and marks the whole text as changed so your browser doesn't freeze.
Can it compare Word or PDF files?
Copy the text out of each file and paste it here. Formatting such as bold or font size isn't compared, only the words.
Why are two lines that look identical marked as changed?
Usually something you can't see: a space at the end of a line, a tab instead of spaces, or a curly quote in one version and a straight quote in the other. The highlight inside the line points at the spot. Turn on Ignore extra spaces if spacing doesn't matter to you.