Side-by-Side Diff Checker
Compare two texts side by side with highlighted differences. Line-by-line, word-by-word, or character-by-character comparison in dual panels.
What is a side-by-side diff?
A side-by-side diff displays the original and modified texts in two parallel panels, highlighting additions in green and deletions in red for easy comparison.
What compare modes are available?
You can compare texts line-by-line, word-by-word, or character-by-character, depending on the level of detail you need.
Is my data sent to a server?
No, all comparison is done locally in your browser. Your text never leaves your device, ensuring 100% privacy.
What do the highlight colors mean?
Green highlights indicate added content, red highlights indicate removed content, and unchanged lines appear without highlighting in both panels.
Can I compare code files?
Yes, this tool works perfectly for comparing code, scripts, configuration files, and any text-based content.
Is there a file size limit?
Since all processing happens in your browser, the limit depends on your device's memory. For best performance, we recommend files under 1MB.
Can I copy the diff results?
Yes, you can easily copy the comparison results or export them for documentation purposes.
Does it support different line endings?
Yes, the tool handles different line ending formats (CRLF, LF) and normalizes them for accurate comparison.
What is the difference between line diff and word diff?
Line diff shows changes at the line level, while word diff provides more granular comparison showing exactly which words changed within each line.
Can I ignore whitespace differences?
The tool provides options to handle whitespace sensitivity, allowing you to focus on meaningful content changes.
How to Use Side-by-Side Diff Checker
Compare two texts side by side with every difference highlighted, from whole lines down to single characters. The comparison runs entirely in your browser, so your text never leaves your device.
- Paste the original text into the left panel and the modified text into the right panel.
- Under the Mode label, pick Line-by-line, Word-by-word, or Character-by-character to set how finely differences are matched.
- Toggle the Side-by-Side and Unified buttons to switch between dual panels and a single merged view.
- Scan the highlighted blocks to see additions, deletions, and edits at a glance.
If two lines look identical but still show as different, switch to Character-by-character mode — hidden trailing spaces or different punctuation are usually to blame.
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