Diff checker — compare two texts line by line
Compare two drafts or configuration snippets without hunting through them line by line. Additions and removals are marked with + and −, and you can hide unchanged lines while reviewing an edit.
Runs in your browser — your input is not uploaded to ToolsNow.
How to use
- Paste both versions. Put the earlier text in Original and the revision in Changed. The comparison updates as you edit either box.
- Read the marked lines. + means added to the revision; − means removed from the original. The two number columns refer to the original and changed versions.
- Adjust the comparison. Use Ignore case or Ignore whitespace only when those differences are unimportant. Show only changed lines hides the surrounding unchanged text.
- Copy the comparison. Copy diff includes all lines with their markers, even when Show only changed lines is on.
Questions
Why does changing one word mark the whole line?
This is a line-by-line comparison. An edited line appears as a removal followed by an addition; it does not highlight individual changed words within that line.
Will Ignore whitespace fix differences caused by wrapping?
It ignores spaces at the ends of each line and treats runs of whitespace within a line as one space. It does not join lines. If a paragraph was wrapped at different positions, give both versions the same line breaks before comparing.
How are moved or repeated lines shown?
The longest-common-subsequence algorithm finds a minimal set of line insertions and deletions under your chosen comparison rules. It does not label moves, and repeated lines can have more than one equally short explanation.
Can I compare a large log file?
The comparison builds a table for every pairing of lines in the two inputs. Time and memory grow with both line counts, and large logs can stall the tab. Compare the relevant sections rather than an entire log.
Are the two texts uploaded?
The comparison processes both inputs in your browser without uploading them. That describes the document handling; page analytics are covered separately in the site’s privacy policy.
Published by ToolsNow. How tools and sources are checked · Report a problem