# Text Diff Checker

URL: https://tools.otaku-dojo.com/en/text-diff-checker
Updated: 2026-10-03

The Text Diff Checker compares an "Original" and a "Changed" text line by line, marking added lines in green and removed lines in red, and counts added, removed and unchanged lines. You can ignore whitespace or case differences, show only changed lines and export the result as a unified diff.

## How to use the Text Diff Checker

1. Paste the old version into "Original" and the new version into "Changed".
2. Optionally turn on "Ignore whitespace", "Ignore case" or "Only changes".
3. Differences appear below: green + for additions, red − for deletions, with original and changed line numbers.
4. Press "Download" for a .diff file or "Copy" to copy the changes.

## Specs & key facts

- **Granularity**: Line by line (longest common subsequence algorithm)
- **Options**: Ignore whitespace, ignore case, only show changes
- **Export**: Unified diff (.diff)
- **Recommended size**: Up to a few thousand lines per side
- **Processing**: In your browser (nothing is uploaded)
- **Price**: Free, no sign-up

## Examples: Compare a config change

```diff
Original:
port=80
host=localhost
debug=true

Changed:
port=443
host=localhost
```

→

```diff
-port=80
+port=443
 host=localhost
-debug=true
```

## FAQ

### Can I compare Word or PDF files?

Copy the document text and paste it as plain text. The tool compares text, not fonts or formatting.

### Why is a whole line shown as removed and added when I changed one word?

The comparison works per line, so any change within a line shows the old line as removed and the new line as added.

### What does "Ignore whitespace" ignore?

It treats runs of whitespace as one space and ignores leading and trailing whitespace — useful for code with different indentation.

### Is my text stored?

No. The comparison runs in your browser and nothing is uploaded.