Text Diff Checker

Example comparison

Here's a small example of what the Text Diff Checker highlights. Paste the "before" version into the original box, the "after" version into the revised box, and click Compare Text.

Q3 revenue grew by 12% compared to last year.
The team added two new members in October.
Customer satisfaction remained steady at 88%.

Q3 revenue grew by 15% compared to last year.
Customer satisfaction remained steady at 88%.
A new support channel launched in November.

Comparing these two blocks would show the first line as modified, with "12%" and "15%" highlighted at the word level, the line about new team members as removed, the customer satisfaction line as unchanged, and the line about the new support channel as added.

How it works

The Text Diff Checker normalizes line endings (Windows, Mac, and Unix line breaks all work the same), then compares the two texts line by line using a deterministic line-matching rule. Lines that exist in both texts are shown as matching. Lines that only exist in the original are marked as removed, lines that only exist in the revised text are marked as added, and a removed line immediately followed by an added line is shown as a single paired "modified" row, with inline highlights on the words that changed. In the side-by-side view, modified rows show the old line on the left and the revised line on the right; in the unified view, the old line is stacked directly above the revised line.

This is a simple line-level diff for pasted text, not a file comparison or merge tool. It does not open files, and it does not try to understand meaning — it only compares the lines you paste, as text.

The three options let you ignore differences you don't care about: "Ignore extra spaces" trims each line and collapses repeated spaces before comparing, "Ignore case" makes the comparison case-insensitive, and "Ignore blank lines" drops empty lines from the comparison entirely. The text shown in the results always matches exactly what you pasted — the options only affect how lines are matched. "Wrap long lines" controls whether long lines wrap or scroll horizontally, in both input boxes and the diff output.

Comparing a messy first draft copied from a PDF? Run it through the PDF Text Cleaner first so line breaks don't throw off the comparison.

Common uses

People reach for this tool whenever they need to see exactly what changed between two versions of pasted text:

• Comparing two versions of a note, email, paragraph, or report section to see what was edited.
• Checking what changed after editing a piece of copied text.
• Comparing cleaned text against the original to confirm only formatting changed, not wording.
• Reviewing small documentation changes line by line before accepting them.
• Checking copied Markdown or plain-text revisions.

If the text you're comparing still has Markdown symbols like ** or # from a chat export, running it through the Markdown Paste Cleaner first can make the comparison easier to read.