Text Diff / Compare
Compare two text blocks side-by-side to find differences.
Diff Result
About text diffing
Comparing two pieces of text — two versions of a paragraph, the output of two API calls, two log files — is one of those tasks that comes up surprisingly often and benefits massively from a side-by-side highlight. This tool produces a Git-style diff with added, removed and changed lines colour-coded so the differences pop out immediately, regardless of how long the inputs are.
The diff is computed in your browser using a Myers-style longest-common-subsequence algorithm. The text never leaves the page, so confidential drafts, internal emails or proprietary code can be compared safely.
How to use
- Paste the original text into the left pane.
- Paste the updated text into the right pane.
- Lines are aligned and differences highlighted automatically.
- Toggle word-level highlighting for finer-grained changes inside individual lines.
Common use cases
- Reviewing edits to a marketing copy without sending tracked-changes Word documents around.
- Comparing two output files from a script run before and after a code change.
- Spotting unintended whitespace changes during code review.
- Auditing differences between two configuration variants.
Frequently asked questions
Does it ignore whitespace?
By default, no — whitespace differences show up as changes. Toggle the "ignore whitespace" option to suppress them.
Can it diff two large files?
Yes, up to a few megabytes per side. The browser starts to slow down past that point.
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