DEC
16HEX
0x10OCT
0o20BIN
0b00000000000000000000000000010000Bit grid (click any bit to toggle)
Named bitfields
No fields defined. Add one or load a preset.
8/16/32/64-bit BigInt-safe bitmask editor with clickable bits and named-field decoding (signed/enum).
160x100o200b00000000000000000000000000010000No fields defined. Add one or load a preset.
Your vote is saved on this device only.
The Bitmask & Bitfield Decoder lets you inspect and edit raw integer values one bit at a time. Toggle individual bits by clicking them across 8, 16, 32, or 64-bit widths, then read the result back in binary, hex, and decimal. Using BigInt math, it handles full 64-bit values without precision loss, and it can break a value into named fields decoded as signed integers or enum labels, so you can see exactly what each segment of a packed register or status word means.
It is built for embedded developers, protocol engineers, and anyone working with marine and hardware data formats that pack flags and codes into integers. Instead of doing bit arithmetic by hand or trusting a calculator that overflows past 53 bits, you get an accurate, interactive view. It is completely free and runs entirely in your browser, so the values you decode never leave your machine.
No. The decoder runs fully client-side in your browser, so every value and field definition stays on your device and nothing is sent to a server. It is free to use without an account.
Many calculators rely on JavaScript numbers that lose accuracy beyond 53 bits, corrupting 64-bit values. This tool uses BigInt arithmetic so all 64 bits stay exact.
Yes. You can flag any named field as signed, and the tool interprets the extracted bits using two's complement to show the correct negative or positive value.
Attach labels to specific numeric values for a field, and the decoder displays the matching label instead of a raw number, which is useful for status codes and type identifiers.
You can work at 8, 16, 32, or 64 bits and switch between them at any time, with the bit grid and outputs updating to match the selected width.