The diff tool was developed for Unix in the 1970s and is still used as the foundation technology for version control systems like Git and SVN.
Among programmers, 'diff' is commonly pronounced as 'diff', which is an English word meaning 'difference' or 'distinction'.
The green and red color coding seen on GitHub and GitLab is based on this diff tool's display format.
In large-scale software development, hundreds to thousands of diffs can be generated daily.
There are multiple diff display formats including Unified diff, Context diff, and Side-by-side diff, used according to different purposes.
Q1
Yes. Use the 'Upload File' button to upload various text file formats including .txt, .md, .js, .css, .html, and more. Both files are compared simultaneously for efficient analysis.
Q2
You can check 'Ignore Whitespace' in the options to ignore whitespace differences during comparison. This is useful for comparing code with different indentation styles.
Q3
Yes. Use the 'Export Diff' button to save the diff results as a text file with line numbers and change markers. This format is compatible with version control systems like Git.
Q4
Supports a wide range of formats including text files (.txt), markdown (.md), programming code (.js, .ts, .jsx, .tsx, .css, .html), and configuration files (.json, .xml, .csv). Any text-based file can be compared.
Q5
Files with thousands of lines can be compared without issues. For very large files (tens of thousands of lines), processing time may increase depending on browser performance, but the comparison will still work.
Q6
Absolutely. It accurately detects differences in indentation, whitespace, variable names, and function additions/deletions - essential for code reviews and version control workflows.
Q7
Yes. On mobile devices, it automatically switches to a vertical layout with L (Left) and R (Right) labels, making it easy to view differences even on small screens. Touch gestures are supported for navigation.
Q8
All processing is done within your browser, and no text data is sent to servers. You can safely use it with confidential documents and files containing personal information. No data is stored or transmitted.
This information is general content. Please also refer to official sites and specialized books for details.