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YFT
Client-side ProcessingUpdated 2026-02-11Report issue

Runs fully in your browser. Inputs stay on your device. See recent fixes on changelog.

Leap Year Checker

Check if a year is a leap year and find nearby leap years.

FreeRuns in browserleap year checkeris leap year
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About Leap Year Checker

Check if a year is a leap year and find nearby leap years. Check if any year is a leap year online for free. See the divisibility rules, next and previous leap years, and total days in the year with formula explanation. Uses precise mathematical formulas with clear, formatted results. Input validation prevents errors and guides correct usage, ensuring reliable computations every time. Everything runs client-side in your browser for maximum speed and privacy — no data is sent to any server, and no signup is required.

Related tools: Day of Year Calculator, Date Difference Calculator, Calendar Reference

How to Use Leap Year Checker

  1. Fill in the required input fields with your values.
  2. Click Calculate to run the computation.
  3. View the results below the form.

Frequently Asked Questions

What is Leap Year Checker?
Check if any year is a leap year online for free. See the divisibility rules, next and previous leap years, and total days in the year with formula explanation.
How are calculations performed?
Calculations use precise mathematical formulas implemented in JavaScript. The underlying formulas are well-documented and validated against known reference values to ensure correctness.
Can I use decimal values?
Yes, all input fields accept decimal numbers with full floating-point precision. You can enter values with as many decimal places as you need and the tool will compute accurate results.
Are the formulas used shown?
Where applicable, the tool displays the formula or methodology used so you can verify the computation yourself. This transparency helps you understand and trust the results.
Is Leap Year Checker free to use?
Yes, this calculator is completely free to use. No account or signup is needed, and all computations run locally in your browser without any restrictions.
Is my data safe when using Leap Year Checker?
Absolutely. Every calculation runs locally in your browser. No input data is transmitted to any server, ensuring your numbers stay private.

Related Tools

Day of Year Calculator
Find the day number (1-366) for any date in the year.
Date Difference Calculator
Calculate the difference between two dates in various units.
Calendar Reference
View monthly calendars and look up dates for any year.