Diff Checker
Paste two versions of text and see exactly what changed — line by line, side by side.
Diff Checker Examples
Click any card to tryHow to Use Diff Checker
To compare two texts, paste the first version into the left text area and the second version into the right text area, then click Compare. The tool performs a line-by-line diff and highlights additions in green and deletions in red, making it easy to see exactly what changed between the two versions.
The summary panel shows the total number of additions, deletions, and unchanged lines. This tool is useful for comparing document drafts, reviewing code changes without a version control system, checking what changed between two versions of a configuration file, or verifying edits made to any text.
Frequently Asked Questions
How does the diff algorithm work? expand_more
The diff algorithm compares the two texts line by line (and optionally word by word) using the Longest Common Subsequence algorithm, which finds the minimum number of additions and deletions needed to transform one text into the other.
Can I compare code with this tool? expand_more
Yes. The diff checker works with any plain text including source code, configuration files, JSON, CSS, and HTML. It highlights all line-level and character-level changes.
Can I see changes at the character or word level? expand_more
Yes. In addition to line-level diff, the tool supports inline highlighting that shows exactly which words or characters within a changed line were added or removed.
Is there a size limit for the texts I can compare? expand_more
There is no enforced server-side limit. The comparison runs entirely in your browser, so very large documents may be slow to process depending on your device.
Can I use this to compare two versions of a document? expand_more
Yes. This is one of the most common use cases. Paste version A and version B of any document and the tool shows you every line that was added, removed, or unchanged.
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