Diff checker
Paste two versions of a text and see exactly what changed.
Paste text, open a file, or drop one here
Paste text, open a file, or drop one here
Differences
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How to use Diff checker
Add both versions
Paste the original on the left and the changed text on the right, or open a file on each side.
Choose how to compare
Pick side by side or unified view, and ignore whitespace or case if those changes don’t matter.
Review and save
Additions are green and removals red, with changed words marked. Copy or download the unified diff.
Why use Utils365
Line and word changes
Changed lines are paired up and the words that differ are highlighted, so small edits are easy to spot.
A real patch file
Download a standard unified diff that git apply and patch understand, or copy it into a code review.
Skip the noise
Ignore whitespace and case to focus on real changes, and long unchanged stretches fold away.
Private by design
Both texts are compared in your browser and never uploaded, so contracts, code and configs stay with you.
Frequently asked questions
How do I compare two text files?
Use Open a file above each box to load the original and the changed version, or drop the files onto the boxes. The differences appear straight away.
What do the colours mean?
Red lines were removed from the original and green lines were added in the changed text. Inside a changed line, the words that differ are highlighted more strongly.
What is a unified diff?
A plain-text format that lists removed lines with - and added lines with +, plus a few unchanged lines for context. Tools like git, patch and code review sites all read it.
What does Ignore whitespace do?
It treats lines as the same when they differ only in spaces or tabs at the ends, or in how many spaces sit between words. Handy for code that was reindented.
Is the downloaded patch affected by the ignore options?
No. The patch always records the exact differences, so it applies cleanly. The options only change what the page highlights.
Is there a size limit?
Files up to 50 MB can be opened, and up to 20,000 lines of each side are compared. Very different large texts may be too slow to compare, and the page will tell you.