Compare two texts and spot every difference with the Text Compare tool
The Text Compare tool is a line-by-line diff checker that shows you exactly what changed between two pieces of text. Paste the original version into the left box and the changed version into the right box, click Compare, and the tool lines the two up and highlights every line that was added (green), removed (red) or left unchanged. Above the result you get a quick count of how many lines were added, removed and kept the same, so you can see the scale of the changes at a glance. If the two texts are exactly the same, it simply tells you they match.
It's built for anyone who needs to know what moved between two versions of something. Writers use it to see what an editor changed in a draft; developers compare two snippets of code or two configuration files; students and teachers check what was edited in an assignment; and anyone reviewing a contract, a price list or a long block of settings can pin down the exact lines that differ instead of re-reading the whole thing. Because the comparison runs entirely in your browser, there is no upload, no account and no waiting — paste, compare, done.
How to use the diff checker
- Paste or type the original text into the left box and the changed text into the right box.
- If you only care about wording and not letter case, turn on Ignore case.
- If indentation or extra spaces don't matter, turn on Ignore whitespace.
- Click Compare.
- Read the result: green rows with a + were added, red rows with a − were removed, and plain rows are unchanged. The pills above show the totals.
- Use Clear to empty both boxes and start a fresh comparison.
How the line-by-line comparison works
The tool splits each side into lines and then finds the longest sequence of lines that appears in the same order in both texts — the part that stayed the same. Anything that doesn't fit into that shared sequence is marked as either removed from the original or added in the changed version. This is the same logic behind the "diff" output you see in coding tools and version control, which is why a single edited line usually shows up as one removed line plus one added line: the old wording is taken out and the new wording is put in its place. Lines are matched whole, so the comparison works on plain prose, lists, code, CSV rows or any text where each line is a meaningful unit.
When to ignore case and whitespace
Ignore case treats "Hello" and "hello" as the same line, which is handy when you only care about the words and not whether something was capitalised. Ignore whitespace collapses runs of spaces and tabs and trims the ends of each line, so a line that was merely re-indented or had trailing spaces won't be flagged as a change. Leave both off when capitalisation and spacing genuinely matter — for example when comparing code where indentation is significant, or text where a capital letter changes the meaning. A good habit is to compare once with both switches off to see everything, then turn them on to filter out the noise and reveal only the substantive edits.
Practical tips and limits
For the cleanest results, paste both texts in the same format — if one side has Windows line endings and the other has Unix line endings, the tool normalises them for you, so that alone won't create false differences. Comparing two lists? Sort both sides first if order doesn't matter to you, otherwise a moved line counts as one removal and one addition. The tool compares up to 1500 lines per side, which covers most documents, articles and code files; for anything larger, split it into sections and compare them one at a time. The comparison is exact within those rules, so what you see highlighted is precisely what differs between the two inputs.
Is my text private?
Yes. Everything happens locally in your browser — the comparison is done in JavaScript on your own device, and nothing you paste is ever sent to a server, uploaded or stored anywhere. That makes it safe for sensitive material like contract drafts, private code or confidential notes. The tool is completely free, needs no sign-up, and you can close the page at any time to clear everything you entered.