Text Compare
Compare two versions of text line by line and see what changed.
Paste an original version on the left and a modified version on the right, then press Execute Comparison to see what changed. Matching lines are shown plainly, differing lines are highlighted as removed or added, and two counters tally the totals. It is handy for spotting edits between two drafts, two config files, or two lists. The comparison happens entirely in your browser — neither version is uploaded.
How the comparison works
The tool lines the two texts up by position: line 1 of the original is compared with line 1 of the modified, line 2 with line 2, and so on to the end of the longer text. Where a pair of lines is identical, the line is shown neutral. Where they differ, the original line is marked removed with a minus and the modified line is marked added with a plus. The Lines Added and Lines Removed counters below sum those up so you get a quick sense of the scale of the change.
It compares by position — an important limit
This is a straightforward same-position comparison, not a smart diff that re-aligns matching text. That distinction matters: if you insert or delete a line near the top, every line below it shifts by one and will be flagged as changed, even where the wording is untouched. So the tool is at its best when the two versions are already mostly aligned — comparing tweaks to the same paragraphs, edits to a settings file, or two similar lists — rather than text that has been heavily reordered or restructured.
Exact matching, and your text stays local
Lines must match character for character to count as equal, so the comparison is case-sensitive and whitespace-sensitive: a difference in capitalisation, or a stray trailing space, is enough to mark a line as changed. That precision is useful for catching subtle edits, but it means cosmetic differences show up as real ones. Both texts are compared on your device and nothing you paste is sent to a server.
Frequently Asked Questions
How does it decide what changed?
It compares the two texts line by line at the same position. Identical lines are neutral; where a position differs, the original line is marked removed and the modified line is marked added.
Why are so many lines flagged after I only inserted one?
Because it compares by position. Inserting or deleting a line shifts everything below it, so those lines no longer line up and are marked as changed. It does not realign text the way a full diff tool would.
Does it ignore case or trailing spaces?
No. Matching is exact, so different capitalisation or an extra space makes two lines count as different. This catches subtle edits but also flags purely cosmetic ones.
Is my text uploaded anywhere?
No. Both versions are compared in your browser when you press the button, and nothing is sent to a server or stored after you leave the page.