Text Diff Checker

Find and view line-by-line differences between two texts, highlighted.

Text Diff Checker completes this text task in seconds, without the manual back-and-forth. With Text Diff Checker, this kind of text edit becomes as simple as copy and paste. The whole process happens locally in your browser; nothing is sent to a server.

Step-by-step

Paste the original or older version into the 'Text 1' box. Deciding up front which text comes first makes it much easier to read what was added and what was removed.
Paste the edited or newer version into the 'Text 2' box.
Click 'Run'. The two texts are matched line by line and the lines that differ are highlighted in color.
Scan the highlighted lines from top to bottom. A line counts as changed even if only one letter moved, so read each marked line in full to spot the actual edit.

Example

You sent a draft rental agreement to the other party and it came back with edits, but nobody told you what changed. Put your version in Text 1 and theirs in Text 2, run the check, and only the touched clauses stand out. If a number in the deposit clause or a single word in the notice period was changed, you can go straight to those lines instead of rereading the whole contract.

The same approach works for comparing two versions of a config file, a translation that came back with corrections, or a privacy policy you saved on two different dates.

Comparing text

The diff checker compares two texts line by line and shows added, removed and common lines. The comparison is exact: differences in case, punctuation and whitespace make a line different. Each text can have at most 500 lines; the comparison runs in your browser.

When comparing

Even a one-character difference in a line can show that line as “removed + added”; this is not a word-level diff.
Differences in whitespace and line endings also show up as changes; clean them first if they are irrelevant.
For texts over 500 lines, compare in sections.
For legal documents, also have an expert check before the final decision.

Things to keep in mind

The comparison works per line. If a long paragraph sits on a single line, one small change marks the whole paragraph as different. Breaking paragraphs into one sentence per line gives a much sharper result.
Trailing spaces you can't see, or curly quotes picked up when copying from Word, can make two lines that look identical show up as different.
Files saved on Windows and on Mac or Linux can use different line ending characters. If you get far more differences than you expected, check this first.
For files running to several hundred lines, the diff view in Git or a desktop comparison tool is easier to work through.