How to use Diff Checker

Paste the first version into Original text and the second into Changed text. The differences appear as you type.

Removed text is red and added text is green. In a changed line, the words that changed are highlighted.

Choose Words or Characters to compare prose or short codes, and turn on Ignore case or Ignore extra spaces when those don’t matter.

Switch between Side by side and Inline. Long unchanged stretches are folded; click to show them.

Copy the diff to share it: lines come as a unified diff, words and characters with [-removed-] and {+added+} marks.

How it works

The checker finds the smallest set of removals and additions that turns the original text into the changed one, the same method git and most diff tools use. It runs in your browser, so the texts never leave your device.

Compare	Best for	What counts as one change
Lines	Code, lists, config files, anything with one item per line	A line removed, added or edited. Inside an edited line, the changed words are highlighted
Words	Paragraphs, articles, contracts	A word or a run of words
Characters	Short codes, IDs, serial numbers, single sentences	A letter, digit or symbol. Texts over 20,000 characters are compared by word instead

When a line is edited, it’s shown next to the line it replaced, matched by the words they share. Lines with nothing in common show as one removed and one added.

Options

Ignore case: “Hello” and “hello” count as the same.
Ignore extra spaces: in Lines mode, spaces at the start and end of a line and runs of spaces inside it don’t count, so reindented code and double spaces don’t show as changes. In Words and Characters mode, any run of spaces matches any other.
A final line break at the end of a text doesn’t count, and Windows and Mac line endings are treated alike.

Reading the result

Side by side puts the original on the left and the changed text on the right, with line numbers for each. Inline shows one column, removed lines with a minus and added lines with a plus. Phones start with Inline.
Long stretches of unchanged lines are folded, keeping three lines around each change. Click Show to unfold them.
If the texts are very different, the changed part may be shown as one removed block and one added block, so the page stays fast.

Copying the diff

Copy diff gives you the differences as text:

Lines: a unified diff, the format git, GitHub and the patch command use. Lines starting with - were removed, lines starting with + were added, and @@ -3,4 +3,5 @@ means the next lines start at line 3 of each text.
Words and characters: the changed text with removals marked [-like this-] and additions {+like this+}, as git diff –word-diff shows them.

Questions

How do I compare two texts for differences?

Paste one version into each box. Every line that changed is marked, removed text in red and added text in green, with the changed words highlighted inside each line. Choose Words to compare paragraphs of prose.

How do I compare two Word documents?

In Word, use Review, then Compare, then Compare, and pick both files. In Google Docs, use Tools, then Compare documents. To compare just the text, copy each document into a box here.

How do I compare two files in VS Code or Notepad++?

In VS Code, select both files in the Explorer, right-click and choose Compare Selected. Notepad++ needs the Compare plugin, from Plugins, then Plugins Admin. From a terminal, git diff --no-index file1 file2 works on any two files.

What do the red and green colors mean?

Red is text that’s in the original but not in the changed version: it was removed. Green is text that’s only in the changed version: it was added. A line that was edited shows both, with the changed words in a stronger color.

Is it safe to paste private text into a diff checker?

This one runs in your browser: the texts are compared on your device and never uploaded or saved. Tools that let you save or share a diff keep a copy on their servers, so check how a tool works before pasting contracts, code or passwords.

Updated October 20, 2026 · Works in current Chrome, Edge, Firefox and Safari · Runs entirely in your browser