Date & Time Tools
Leap Year Checker
Check whether a year is a leap year and why.
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What is Leap Year?
A tiny but exact calendar tool. It applies the full Gregorian leap-year rule — 2000 was a leap year, 1900 was not.
How it works
The rule is: divisible by 4, but not by 100, unless also divisible by 400. The tool also reports February's length for that year.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Paste or type any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
Nothing is uploaded — every tool in this category runs entirely in your browser.