What does the Hex / Modbus decoder do?

It converts raw hex bytes and Modbus register values into decimal, binary and IEEE-754 float, and shows all four byte-order interpretations (ABCD, BADC, CDAB, DCBA) side by side — the fastest way to make sense of a raw register dump.

Why does my Modbus float read as a wrong value?

Almost always byte or word order. A 32-bit float lives in two 16-bit registers and vendors order them differently; the same four bytes give four different numbers. Paste the registers into the decoder and see which order produces a sensible value.

How are negative numbers stored in Modbus registers?

As two's-complement signed integers — int16 in one register or int32 across two. A raw reading like 65535 in a signed register is actually −1, so decode with the signed interpretation the device datasheet specifies.

How is an IEEE-754 float carried over Modbus?

The 32-bit float is split across two consecutive 16-bit registers. The standard does not fix the word order, so each vendor picks one — which is why a byte-swap decoder is a daily tool when integrating meters.

Resources · Online Tool

Modbus Hex Converter

Paste the hex you read from a meter or PLC — see every value it could be (Int, UInt, Float · ABCD / BADC / CDAB / DCBA), check the Modbus CRC, and encode values back into register bytes. Runs entirely in your browser — nothing is uploaded.

HEX IN

Input

spaces, commas, 0x, newlines — all fine

8 bytes4 registers64 bits

try:

CRC-16 / Modbusof these bytes: 0x2173append 73 21

BYTES

Register breakdown

click a byte to move the decode window

Decode window start

bytes 0–7

DECODE

What could this be?

every type × every byte order — click a value to copy

Looks like3.141592653589793Float64 · ABCD Big-Endian

Or a date/time2004-01-17T11:52:27Z UTCUnix epoch · UInt32 · ABCD Big-Endian

Type	A B C DBig-Endian	B A D CByte Swap	C D A BWord Swap	D C B ALittle-Endian
16-bit · 1 register
UInt162B	16 393	2 368	16 393	2 368
Int162B	16 393	2 368	16 393	2 368
32-bit · 2 registers
UInt324B	1 074 340 347	155 253 537	570 114 057	4 213 246 272
Int324B	1 074 340 347	155 253 537	570 114 057	-81 721 024
Float324B	2.1426990032196045	2.3229239576896852e-33	1.7025371545593328e-18	-8.36147406512941e+35
64-bit · 4 registers
UInt648B	4 614 256 656 552 045 848	666 808 865 149 687 853	3 249 439 782 752 436 233	1 742 123 762 643 437 888
Int648B	4 614 256 656 552 045 848	666 808 865 149 687 853	3 249 439 782 752 436 233	1 742 123 762 643 437 888
Float648B	◆ likely3.141592653589793	4.213048598159337e-264	1.866158485428959e-91	3.207375630676366e-192

TEXT

ASCII & binary

full input

ASCII (printable · else ·)

@·!·TD-·

Binary

01000000 00001001 00100001 11111011 01010100 01000100 00101101 00011000

ENCODE

Number → Hex

build register bytes to write back

Value

Type

bytes below, in every order — click to copy

TEXT⇄HEX

Text ↔ Hex

Text → Hex

57 54 34 36 30 4D

Hex → Text

WT460M

All conversion happens locally in your browser — the data you paste never leaves this page.

Loading…

Type	A B C DBig-Endian	B A D CByte Swap	C D A BWord Swap	D C B ALittle-Endian
16-bit · 1 register
UInt162B	16 393	2 368	16 393	2 368
Int162B	16 393	2 368	16 393	2 368
32-bit · 2 registers
UInt324B	1 074 340 347	155 253 537	570 114 057	4 213 246 272
Int324B	1 074 340 347	155 253 537	570 114 057	-81 721 024
Float324B	2.1426990032196045	2.3229239576896852e-33	1.7025371545593328e-18	-8.36147406512941e+35
64-bit · 4 registers
UInt648B	4 614 256 656 552 045 848	666 808 865 149 687 853	3 249 439 782 752 436 233	1 742 123 762 643 437 888
Int648B	4 614 256 656 552 045 848	666 808 865 149 687 853	3 249 439 782 752 436 233	1 742 123 762 643 437 888
Float648B	◆ likely3.141592653589793	4.213048598159337e-264	1.866158485428959e-91	3.207375630676366e-192

Type

A B C DBig-Endian

B A D CByte Swap

C D A BWord Swap

D C B ALittle-Endian

16-bit · 1 register

UInt162B

16 393

2 368

16 393

2 368

Int162B

16 393

2 368

16 393

2 368

32-bit · 2 registers

UInt324B

1 074 340 347

155 253 537

570 114 057

4 213 246 272

Int324B

1 074 340 347

155 253 537

570 114 057

-81 721 024

Float324B

2.1426990032196045

2.3229239576896852e-33

1.7025371545593328e-18

-8.36147406512941e+35

64-bit · 4 registers

UInt648B

4 614 256 656 552 045 848

666 808 865 149 687 853

3 249 439 782 752 436 233

1 742 123 762 643 437 888

Int648B

4 614 256 656 552 045 848

666 808 865 149 687 853

3 249 439 782 752 436 233

1 742 123 762 643 437 888

Float648B

◆ likely3.141592653589793

4.213048598159337e-264

1.866158485428959e-91

3.207375630676366e-192