Highlight Differences Between Two Pasted Texts
Free · No sign-up · Nothing uploaded
Paste two texts and see their differences highlighted — added, removed, changed, and matching lines clearly marked. Useful for drafts, emails, notes, and copied text revisions. Everything runs in your browser.
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.
Original
Q3 revenue grew by 12% compared to last year. The team added two new members in October. Customer satisfaction remained steady at 88%.
Revised
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 matching and highlighting work
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. Lines that appear in both texts are treated as matching and shown as unchanged. Lines that only exist in the original are highlighted as removed, lines that only exist in the revised text are highlighted 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.
How to Use
- 1 Paste the original text into the Original text box on the left.
- 2 Paste the newer version into the Revised text box on the right.
- 3 Click Compare Text and review the highlighted differences.
- 4 Switch between side-by-side and unified views, filter rows, or click Copy Summary for the counts.
Common Uses
- 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
Common Questions
Does my text get uploaded anywhere?
No. We do not upload or store your text. The comparison runs as JavaScript on your device; there is no server that receives your text, and nothing is kept after you close the tab.
Is this a file diff or merge tool?
No. This tool compares two blocks of pasted text line by line. It does not open, upload, or merge files, and it has no conflict-resolution features.
What counts as an added or removed line?
Each line of the original text is matched against the closest corresponding line in the revised text. Lines that appear only in the revised text are "added", lines that appear only in the original text are "removed", and a removed line immediately followed by an added line is shown as a paired "modified" row.
Can it compare drafts or copied text?
Yes. Paste two versions of a draft, email, note, or any other copied text into the two boxes and click Compare Text to see exactly which lines were added, removed, or modified.
Is any of this done with AI?
No. The comparison is a deterministic, rule-based line diff. The same two inputs always produce the same result, and no text is sent anywhere for processing.
Related Tools
Clean up before you compare
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like ** or # from a chat export, running it through
the Markdown Paste Cleaner first can make the
comparison easier to read. The Duplicate Line
Remover does the same for messy
lists, logs, or copied notes with repeated lines. Browse all tools →