IEEE-754 Float Inspector
Enter a number to see its exact IEEE-754 32-bit and 64-bit bit pattern.
Look inside a floating-point number
Computers store decimals as IEEE-754 floating point: a sign bit, an exponent, and a fraction. That format explains rounding quirks and precision limits, and this inspector lays out the exact bits for any number you enter.
The friendly-looking 0.1 is stored in 32-bit float as sign 0, exponent 01111011, mantissa 10011001100110011001101 — clearly not exact, which is the root of classic 0.1 + 0.2 surprises. Both single and double precision are shown.
Exact and private
The bit patterns come straight from a typed-array view, so they match what the hardware stores, and everything runs in your browser.
Frequently Asked Questions
What does it reveal?
How a number is actually stored as a float: the sign bit, the exponent field, and the mantissa (fraction) bits, plus the raw hexadecimal, for both single and double precision.
Why do some decimals look odd?
Values like 0.1 have no exact binary fraction, so the stored bits are the nearest representable value — which is why floating-point arithmetic sometimes surprises you.
How are the bits computed?
With a DataView over an ArrayBuffer, so the pattern is exactly what your CPU would store, not an approximation.
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