Diff Checker
Compare two texts and see exactly what changed.
FREE - NO SIGN-UP - RUNS ON YOUR DEVICE
Runs in your browser tab
- 2comparison levels
- 2switches
- 0uploads
- 1 tapto copy
What you can count on
- 2levels
- Whole lines, or words within a line
- Switch without repasting
- 2switches
- Ignore whitespace, ignore letter case
- Both change the count live
- 0uploads
- Both texts stay in this tab
- Nothing is sent anywhere
Diff Checker at a glance
- Input
- Two boxes of text
- Levels
- Line level or word level
- Ignore whitespace
- Spacing changes ignored
- Ignore case
- Capital changes ignored
- Count
- Added, removed, unchanged
- Output
- Highlighted, or plus and minus
- Reading the result
- Counts, hover labels, swap
- Price
- Free
- Account needed
- None
- Where processing happens
- On your device
How to use Diff Checker
- 1
Paste both versions
The original on the left, the changed version on the right. Both boxes start with a sample.
- 2
Choose the level
Line level for whole lines, word level for the words inside a line, plus the two switches.
- 3
Read or copy
Additions are green, removals struck through in red, and one tap copies a plus and minus version.
Frequently asked questions
What is the difference between line and word level?
Line level marks whole lines that changed, which suits code and configuration. Word level marks the words inside a line, which suits prose where one word moved.
When should I ignore whitespace?
When only indentation or spacing moved. Reindented code shows as a wholesale rewrite otherwise, and the switch clears that noise away in one tap.
Are my texts uploaded anywhere?
No. The comparison runs in this browser tab and neither text is sent to a server. Close the tab and nothing is left behind.
Can I compare two files?
Open each one, copy its contents and paste it into a box. This page compares text you paste rather than reading files from your disk.
What does Ignore whitespace actually change?
At word level it switches to a different comparison altogether, one that treats runs of spaces as nothing rather than as text. Two files differing only in indentation come back identical.
Reading the result
Paste the original on the left and the changed version on the right. Additions are shown in green and removals struck through in red, with a plain count of what moved.
- Green means added to the second version; struck-through red means removed from the first.
- The count is in lines or words, matching whichever level you chose.
- Swap the two sides to see the same change described the other way round.
- The copied version marks each line with a plus, a minus or a space.
Full specification
| Input | Two boxes of text, both already filled with a sample so the marking explains itself. |
|---|---|
| Levels | Line level for whole lines that changed, word level for the words inside a line. |
| Ignore whitespace | Lines that differ only in spacing or indentation are counted as unchanged. |
| Ignore case | Text that differs only in capitals is counted as unchanged. |
| Count | Added, removed and unchanged, counted in lines or words to match the level chosen. |
| Output | Highlighted text on the page, and a plus and minus marked copy for pasting elsewhere. |
| Reading the result | Separate counts for added, removed and unchanged sit above the text, every highlighted run carries a hover label, and one button swaps the two sides. |
| Price | Free. Supported by clearly labeled ads outside the working area. |
| Account needed | No. |
| Where processing happens | In your browser tab. Nothing is uploaded. |
Keep going with the same files
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