No. The diff is computed entirely in your browser; no input data is transmitted.

Is there a size limit?

It's memory-bound. Tens of thousands of lines work but become sluggish.

No, this tool assumes text input.

What does Ignore whitespace mean?

Each line is compared after stripping all whitespace (spaces, tabs, newlines) — not just leading/trailing. So 'a b' and 'ab' are treated as the same line. The displayed text still shows the original.

Is Ignore case ASCII-only?

It uses JavaScript's `toLowerCase()`, so Unicode casing is handled. Display preserves the original casing; only the comparison key is lowercased.

What if both toggles are on?

Both apply. Whitespace is stripped first, then the result is lowercased, so 'Hello World' and 'helloworld' compare as identical.

Back to Developer

Text diff — line and word-level compare

Compare two texts line by line. Supports inline and side-by-side views, word-level highlighting, and ignoring surrounding whitespace. Runs entirely in your browser.

developertextdiff

How to use

Paste the two texts into the left and right textareas. Switch between Inline and Side-by-Side views, optionally enable word-level diff, and tune the comparison with the Ignore whitespace (strips all whitespace in each line, not just leading/trailing) and Ignore case checkboxes. The toggles only affect comparison — the displayed text is always the original. Additions and deletions are highlighted; stats (additions / deletions / identical lines) appear at the bottom. Use Sample to try the tool quickly.

FAQ

Is text uploaded?: No. The diff is computed entirely in your browser; no input data is transmitted.
Is there a size limit?: It's memory-bound. Tens of thousands of lines work but become sluggish.
Can I diff binaries?: No, this tool assumes text input.
What does Ignore whitespace mean?: Each line is compared after stripping all whitespace (spaces, tabs, newlines) — not just leading/trailing. So 'a b' and 'ab' are treated as the same line. The displayed text still shows the original.
Is Ignore case ASCII-only?: It uses JavaScript's `toLowerCase()`, so Unicode casing is handled. Display preserves the original casing; only the comparison key is lowercased.
What if both toggles are on?: Both apply. Whitespace is stripped first, then the result is lowercased, so 'Hello World' and 'helloworld' compare as identical.

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