Diff checker
Paste two versions of anything and see exactly what changed: added in green, removed in red, by line or by word, inline or side by side.
Guide
How to use it
- Paste the original on the left and the changed version on the right.
- Pick Lines for code and configs, Words for prose.
- Choose inline (one merged view) or side by side (aligned columns, line mode).
- Tick ignore whitespace when re-indentation is drowning real changes, ignore case for case-insensitive data.
- Read the counts in the status line: added, removed, unchanged.
Examples
Worked examples
Staging works, production does not. Paste both configs in line mode: one changed timeout and a missing environment variable light up in seconds.
A supplier sends an updated quotation "with minor changes". Word mode shows the minor changes include a delivery date and a 4% price rise.
A formatter touched every line. Ignore whitespace collapses the noise and leaves the three lines where logic actually changed.
Method
How it works
The two texts are split into lines or words and run through a longest-common-subsequence algorithm, the classic approach behind git and every serious diff tool. Whatever is not part of the common subsequence is an addition or removal. The ignore options normalise whitespace and case before comparison but display your original text untouched.
Everything happens in your browser, no upload, which is precisely what you want when the texts are contracts or unreleased code.
FAQ
Frequently asked questions
Which granularity should I use?
Lines for code, configs and anything structured, where a line is the natural unit of change. Words for prose, where a one-word edit should not flag the whole paragraph. The text compare and code diff pages start with the right defaults.
What does ignore whitespace do?
Runs of spaces and tabs are treated as one space and edges trimmed before comparing, so re-indented code or re-wrapped text does not drown the real changes. Blank line changes still show.
Is this a proper minimal diff like git?
It computes a longest-common-subsequence diff, the same family of algorithm git uses, so changes are minimal. Very large inputs are declined rather than approximated.
How big a text can it compare?
Around 2,000 lines per side is comfortable in the browser. Beyond that the tool says so rather than freezing your tab; split large files into sections.
Are my documents uploaded?
No. Both texts are compared on your device, which is the point: contracts, code and unreleased copy should not go to a stranger's server to be compared.
Can it diff two files?
Open each file in any editor and paste the contents. Direct file pickers and folder comparison are on the roadmap.
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