How many hex digits does this tool expect?

Exactly 8 hex digits for a 32-bit single-precision float, or exactly 16 hex digits for a 64-bit double-precision float; in auto-detect mode, the tool picks whichever of those two matches your input's digit count and rejects anything else as ambiguous.

Is this the inverse of the hexfloat (%a) parser?

No, that's Hexfloat to Float Converter's job (parsing notation like "0x1.8p3"). This tool instead decodes a plain run of hex digits representing the value's raw stored bits, with no dot or "p" exponent involved at all, it's the inverse of Floating Point Number to Hex Converter specifically.

What does auto-detect mode do?

It looks at how many hex digits you entered: exactly 8 is decoded as a 32-bit float, exactly 16 as a 64-bit float, and any other digit count is rejected since there's no way to know which precision was intended.

Can this decode special values like Infinity or NaN?

Yes, the standard IEEE-754 bit patterns for Infinity, -Infinity, and NaN (all-ones exponent, with a zero or non-zero mantissa respectively) decode to those values correctly, matching how any IEEE-754-compliant system would read the same bits.

Hex to Floating Point Converter - Decode IEEE-754 Bit Patterns

Overview

Introduction

A raw IEEE-754 bit pattern is only useful once you can read back the actual number it encodes, and that decoding depends entirely on knowing whether it's 32-bit or 64-bit precision.

This tool takes that hex bit pattern and decodes it into the exact decimal float value it represents.

What Is Hex to Floating Point Number Converter?

A decoder that reads a raw IEEE-754 hex bit pattern, 8 hex digits for 32-bit single precision or 16 for 64-bit double precision, and returns the decimal float value it encodes.

It's the direct inverse of Floating Point Number to Hex Converter, and distinct from Hexfloat to Float Converter, which parses an entirely different, human-readable %a-style notation rather than a plain run of raw bit-pattern hex digits.

How Hex to Floating Point Number Converter Works

The hex digits are validated and, for 32-bit input, written into a 4-byte buffer as an unsigned integer via DataView's `setUint32`, then read back out as a float using `getFloat32`; 64-bit input uses an 8-byte buffer and `getFloat64` with the two 32-bit halves written separately.

In auto-detect mode, the input's digit count (8 or 16) determines which precision to use before this same decode step runs; any other digit count is rejected as ambiguous.

When To Use Hex to Floating Point Number Converter

Use it whenever you have a raw IEEE-754 hex value, from a memory dump, binary file, network packet, or hex editor, and need to know what decimal number it actually represents.

It's also a fast way to double check a manual IEEE-754 decoding exercise or confirm the output of Floating Point Number to Hex Converter round-trips correctly.

Often used alongside Floating Point Number to Hex Converter, Hexfloat to Float Converter and Float to Hexfloat Converter.

Features

Advantages

Exact, standards-compliant decoding via the browser's native DataView implementation.
Supports both 32-bit and 64-bit precision, plus an auto-detect mode based on digit count.
Correctly decodes zero, negative zero, Infinity, and NaN bit patterns.

Limitations

Requires an exact digit count for the chosen (or detected) precision; it won't guess at a partial or overlong hex string.
Only supports the two standard IEEE-754 binary widths (32-bit and 64-bit); extended or half (16-bit) precision aren't offered.

Examples

Decoding a well-known 32-bit constant

Input

3F800000 (32-bit)

Output

0x3F800000 is the standard IEEE-754 single-precision bit pattern for exactly 1.0.

Decoding a well-known 64-bit constant

Input

3FF0000000000000 (64-bit)

Output

0x3FF0000000000000 is the standard IEEE-754 double-precision bit pattern for exactly 1.0.

Best Practices & Notes

Best Practices

Use auto-detect mode when you're not sure of the source precision and the digit count alone can disambiguate it (8 vs. 16 digits).
Double check you're not accidentally pasting hexfloat (%a) notation here instead, this tool expects plain bit-pattern hex digits with no dot or "p" exponent.

Developer Notes

Implemented with `DataView.prototype.setUint32` (big-endian) followed by `getFloat32`/`getFloat64`, the exact inverse of Floating Point Number to Hex Converter's encoding steps; verified against the same well-known constants (0x3F800000 → 1, 0xC0000000 → -2, 0x3F000000 → 0.5, 0x3FF0000000000000 → 1) used to validate that tool.

Hex to Floating Point Number Converter Use Cases

Decoding a float value found in a binary file, memory dump, or network packet capture
Verifying that Floating Point Number to Hex Converter's output round-trips back to the original value
Learning how IEEE-754's sign/exponent/mantissa bits combine into a decimal value

Common Mistakes

Pasting hexfloat (%a) notation like "0x1.8p3" here instead of a plain bit-pattern hex string; use Hexfloat to Float Converter for that format instead.
Entering the wrong digit count for the intended precision (e.g. 8 digits while expecting a 64-bit decode); auto-detect mode helps avoid this by inferring precision from length.

Tips

If auto-detect rejects your input, count the hex digits, it must be exactly 8 or exactly 16, with no partial bytes.
Use Floating Point Number to Hex Converter first to generate a known-correct hex value for testing this tool.

Hex to Floating Point Number Converter