Text Compare
Compare two texts line by line, and see what changed between them.
Text Compare
Are they the same
The two texts are different
- Lines that differ1
- Lines only in the second1
- Lines only in the first1
- How similar they are50.00%
- Line by line The quick brown fox - jumps over the lazy dog + leaps over the lazy dog
Works out in your browser. Nothing you type is sent anywhere.
In short: Text Compare
The two texts are different. Of the lines compared, 1 appear only in the second text and 1 only in the first, while 1 of them look like changes rather than pure additions. The two texts are 50.00% alike, measured on the lines that they share.
What is Text?
Comparing two texts finds the smallest set of additions and removals that turns one into the other, which is what a line-by-line difference shows.
How is Text calculated?
The longest run of lines the two texts have in common, in order, is found first. Everything outside it is either an addition or a removal, which is the smallest honest description of the change. The similarity is the shared lines as a share of both texts together.
- diffthe additions and removals
- longest common subsequencethe longest sequence of lines both texts share, in order
A worked example
| First text | The quick brown fox jumps over the lazy dog |
|---|---|
| Second text | The quick brown fox leaps over the lazy dog |
| Ignore case | No |
| Ignore extra spaces | Yes |
| Result | |
| Are they the same | The two texts are different |
| Lines that differ | 1 |
| Lines only in the second | 1 |
| Lines only in the first | 1 |
| How similar they are | 50.00% |
| Line by line | The quick brown fox - jumps over the lazy dog + leaps over the lazy dog |
Every figure in this table is produced by the same calculation the tool above runs.
How to use this text compare
- Paste the first text into the left box.
- Paste the second into the right one.
- Choose whether case and extra spaces should count as differences.
- Read the line-by-line comparison underneath.
Questions people ask
Does it compare word by word or line by line?
Line by line, which is how source code and documents are usually compared. A line with one word changed shows as a removal and an addition rather than as a highlighted word. For prose, breaking it into one sentence per line before comparing gives a more readable result.
What does the similarity percentage mean?
It is the lines the two texts have in common, counted against both texts together, so identical texts read as fully alike and completely different ones as nothing alike. It is a rough measure and not a standard one. Use the line counts for anything precise.
Should I ignore extra spaces?
Usually yes for prose, where trailing spaces and double spaces are accidental. For code, indentation often matters, so turn it off. The option is there because neither answer is right for everything.
Is there a size limit?
Very long texts fall back to a simpler side-by-side pairing instead of the full comparison, because the exact method grows quickly with length. For ordinary documents and files you will not notice. Nothing is uploaded whatever the size.
Accuracy and sources
Checked by the Daytoolz team on 16 October 2026. How we check our tools.