Text Diff Checker
Compare two texts line by line, review every changed block, choose which version to keep, and download your final document.
How to use the Text Diff Checker
- Enter or upload the original document in Text A.
- Enter or upload the modified document in Text B.
- Click Compare Text to identify matching and changed lines.
- Review each changed block in the comparison table.
- Choose whether to keep the original block or use the modified block.
- Download your assembled final output as a text file.
Unchanged lines are automatically retained. The tool processes text in your PHP application and does not require an external comparison service.
Frequently Asked Questions
How does line-by-line comparison work?
The tool finds the longest common subsequence of the two documents. This allows it to identify matching lines and distinguish additions from deletions.
Can I accept individual changes?
Yes. Each consecutive group of changes has its own selection. You can preserve the original version or apply the modified version independently for every block.
Can I download the merged document?
Yes. The final output preview is assembled from your selections. You can download it as a plain text file or copy it to your clipboard.
Are there comparison limits?
To protect shared hosting resources, each document is limited to 5,000 lines and the comparison is subject to a processing safety limit. Each uploaded file can be up to 2 MB.