Text Diff Checker
Text Diff Checker compare two text versions spot changed lines before after text comparisonCompare two versions without uploading them
Paste the earlier version on the left and the revised version on the right, choose any matching options, then select Compare text. The result marks removed lines with -, added lines with +, and unchanged lines with a space.
What this checker compares
This is a line-by-line comparison for notes, configuration snippets, lists, drafts, and other plain text. It finds a longest shared sequence of lines, then shows where each version diverges. That makes a moved line appear as one removal and one addition, which is usually clearer than pretending the move was an in-place edit.
Reading the result
A blank prefix means the line occurs in both versions at that position in the comparison. A minus sign belongs only to the original; a plus sign belongs only to the revision. The summary counts those three groups. Copying preserves the prefixes so the review can be pasted into a message or issue.
Worked example
Compare an original containing “Apples”, “Bread”, and “Milk” with a revision containing “Apples”, “Coffee”, and “Milk”. The output keeps Apples and Milk, marks Bread with a minus, and marks Coffee with a plus. The summary reports one added, one removed, and two unchanged lines.
Matching choices
Ignore capitalization when Draft and draft should count as the same line. The space option trims only each line's beginning and end; it does not collapse spaces inside a sentence. Displayed output keeps the original spelling and spacing from its source version even when an option makes two lines match.
Assumptions and limitations
The tool compares plain text, not formatting, comments, tracked changes, or file metadata. It does not highlight individual changed words. Very large inputs require more browser memory because sequence matching examines combinations of lines; use a dedicated source-control diff for large files. Text stays in this browser tab, but copied results follow the privacy rules of their destination.
Common comparison mistakes
Check that the older text is on the left if plus and minus direction matters. Line-ending differences are normalized automatically, while blank lines remain meaningful. Turning on both ignore options may hide changes that matter in case-sensitive code or whitespace-sensitive data, so leave them off for exact technical comparisons.
Text Diff Checker FAQ
Does it compare words?
No. Each complete line is the comparison unit.
Can it open files?
No. Paste plain text into both fields.
Does it save either version?
No. Comparison runs locally and the page does not store the pasted text.