Text Diff & Comparison Checker
Find differences between two versions of text, code, or documentation. Visual line-by-line comparison highlighting exact edits.
Line-by-Line Comparison
Spotting what changed between two versions of a document by reading both is unreliable — the eye skips over single-word edits and transposed lines. A diff compares them mechanically and highlights every addition, deletion, and modification. This checker runs the comparison in your browser, which makes it usable for contracts, drafts, and code you would not paste into an online service.
How to compare two texts
- Paste the original version into the left panel.
- Paste the revised version into the right panel.
- Read the highlighted result — additions and deletions are marked distinctly.
- Switch between side-by-side and unified views depending on whether you want context or compactness.
The Text Diff & Comparison Checker runs entirely in your browser — nothing you enter is uploaded, stored, or logged.
When to use this tool
Reviewing contract revisions
When a counterparty returns a document without tracked changes, a diff is the only reliable way to find what they altered.
Comparing configuration files
A single differing line between a working and a failing environment config is usually the whole explanation for an outage.
Checking edits to a draft
Comparing your draft against an editor's returned version shows precisely which changes were made rather than which were described.
Things worth knowing
- Diffs are line-based by default, so reflowing a paragraph marks the whole paragraph as changed even if one word moved.
- Normalise line endings before comparing. A file saved on Windows and another on macOS can show every line as different purely because of CRLF versus LF.
- Trailing whitespace produces differences that are invisible on screen — enable whitespace-insensitive comparison if that noise dominates.
- For prose, word-level diffing is far more readable than line-level.
Frequently Asked Questions
How does the diff algorithm work?
Why is the entire paragraph marked as changed when I edited one word?
Is my text uploaded for comparison?
Can I compare files rather than pasted text?
What is the difference between side-by-side and unified view?
Why do two identical-looking texts show differences?
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