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Diff Checker🔒 100% local
Compare two texts line by line and see differences highlighted.
Diff Checker: related tools
Compares two blocks of text line by line and prints a readable report: unchanged lines keep two leading spaces, lines found only on the left get a minus, and lines found only on the right get a plus. It splits on newlines and compares by position only, with no word-level or fuzzy matching. Both blocks are handled in the page.
Diff Checker: how to use it
- Paste the old version into the left box and the new version into the right.
- Press Compare.
- Read the result - a minus marks a line that is gone, a plus marks a line that is new, and an unmarked line matched at the same row number.
Diff Checker: worked example
Left:
line 1
line 2
line 3
Right:
line 1
line 2 modified
line 4becomes line 1
- line 2
+ line 2 modified
- line 3
+ line 4Diff Checker: when to use it
- Seeing exactly which lines changed between two versions of a config file or a migration script.
- Confirming that a template edit only touched the handful of lines you meant to touch.
- Comparing a pasted API response against the sample in the docs.
Diff Checker: what it does not do
- The comparison never re-synchronises. Insert one line at the top of the right side and every later line is reported as changed, which an alignment-based diff would have shown as a single insertion.
- Trailing spaces and different line endings count as differences, so text copied out of two editors can look busier than it is.
- One empty box is accepted and treated as blank lines, which is handy for spotting appended text but means a genuinely unintended empty paste produces a wall of minus lines instead of an error.