Hex Converter

Convert hexadecimal to decimal, binary, and octal. Encode/decode text to hex bytes, view hex color swatches, generate hex dumps, and add hex numbers.

Hexadecimal (base 16)

Decimal (base 10)

Binary (base 2)

Octal (base 8)

Hex Addition

+ =

Text → Hex Bytes

Hex Output

Hex Bytes → Text (space or no separator)

Text Output

What is a Hex Converter?

A hex converter is a tool that translates numbers between hexadecimal (base 16), decimal (base 10), binary (base 2), and sometimes octal (base 8) or ASCII text. Hexadecimal is a positional numeral system using sixteen distinct symbols: the digits 0–9 and the letters A–F, where A represents 10, B represents 11, and so on through F representing 15. Each hexadecimal digit corresponds to exactly four binary bits, making hex a compact and human-readable representation of binary data.

Hexadecimal is ubiquitous in computing. Memory addresses are expressed in hex (e.g. 0x7FFFFFFF), colour codes in HTML/CSS use hex (e.g. #FF5733), byte values in network protocols and file formats are written in hex, and machine code disassembly is displayed in hex. The 0x prefix is a convention in most programming languages to denote a hexadecimal literal. The hash outputs of MD5, SHA-256, and other cryptographic functions are also displayed as hexadecimal strings.

Hex converters are used by software developers debugging memory issues, web designers picking colours, hardware engineers reading datasheets, cybersecurity professionals analysing packet captures and malware, and computer science students learning number systems. Converting between number bases by hand is error-prone for large values — a hex converter performs the conversion instantly and accurately for values of any size.

How the Hex Converter Works

Formula, assumptions, and calculation steps for this dev tools tool.

Formula Used

Decimal to Hex uses repeated division by 16, mapping remainders 0-15 to 0-9 and A-F

Methodology

Converts between hexadecimal and decimal, or binary, using positional base-16 arithmetic.

Calculation Steps

Provide the input text or select generation options.
Apply the selected encoding, parsing, hashing, or formatting rule.
Validate the output where possible.
Return copy-ready developer output.

Assumptions and Limits

Generated or transformed output depends exactly on the supplied input.
Security-sensitive values should be handled carefully.
Browser tools do not replace production validation.

Frequently Asked Questions

What is hexadecimal?

Hexadecimal (hex) is a base-16 number system using digits 0–9 and letters A–F. It is widely used in computing because each hex digit represents exactly 4 binary bits (a nibble), making it a compact representation of binary data. Two hex digits represent one byte (8 bits).

Why do programmers use hex?

Hex is more human-readable than binary but still maps cleanly to binary. Memory addresses, color codes (#RGB), file permissions, byte values in protocols, and machine code are all commonly expressed in hex. It is much easier to read 0xFF than 11111111.

How do I read a hex dump?

A hex dump shows data as three columns: an address offset (which byte position), the hex values of each byte (usually 16 per row), and the ASCII representation (printable characters shown, non-printable shown as a dot). It is used to inspect raw binary files or network packets.

What is 0xFF in decimal?

0xFF = 255 in decimal. FF in hex is 15×16 + 15 = 255. It represents a byte with all 8 bits set to 1 (11111111 in binary). 0xFF is frequently used as a bitmask in low-level programming to isolate the lowest 8 bits of an integer.

Real-World Applications

🎨

Web Colour Codes

HTML and CSS colour codes (#FF5733, #1A2B3C) are hexadecimal triplets representing RGB values — each pair of hex digits (00–FF) encodes one colour channel 0–255.

🔍

Memory & Debugger Addresses

Debuggers and memory analysers display addresses in hex (0x7FFF5FBFF000) — convert to decimal to understand the actual address offset and verify alignment.

🛡️

Cybersecurity & Forensics

Malware analysts read hex dumps of executable files and network packets to identify shellcode, magic bytes, and encoded payloads without a disassembler.

⚡

Microcontroller Programming

Microcontroller registers, I/O port addresses, and bitfield masks are written in hex in embedded C — e.g. PORTB |= 0x0F enables the lower 4 bits.

📝

IP & MAC Address Analysis

IPv6 addresses and MAC addresses are expressed in hex — convert segments to decimal or binary to perform subnetting, vendor lookup, and address range calculations.

🔐

Cryptographic Output Inspection

SHA-256 and MD5 hash outputs are hex strings — convert individual byte pairs to decimal or binary to analyse the raw digest values.

Common Mistakes

Confusing hex digits A–F with decimal values

In hex, A=10, B=11, C=12, D=13, E=14, F=15. The hex value 0xFF equals 255 in decimal — not 255 multiplied by 16.

Forgetting the 0x prefix in code

In most programming languages (C, Java, Python), hexadecimal literals must be prefixed with 0x — writing FF without the prefix is interpreted as a variable name, not a hex number.

Treating two hex digits as one byte when the length is odd

A hex string must have an even number of digits to represent whole bytes — a single leading digit (e.g. "F3A") should be padded to "0F3A". Odd-length hex strings cause off-by-one byte parsing errors.

Confusing uppercase and lowercase in case-sensitive contexts

While hex digits are mathematically identical in upper or lowercase (0xFF = 0xff), some systems (file format parsers, regex patterns) are case-sensitive. Always normalise case before comparing hex strings.

Converting signed integers without accounting for two's complement

The hex value 0xFF represents 255 as an unsigned 8-bit integer, but -1 as a signed 8-bit integer (two's complement). Always specify whether you're converting signed or unsigned.

Number Base Comparison Reference

Decimal	Hexadecimal	Binary	Octal
0	0x00	0000 0000	000
15	0x0F	0000 1111	017
16	0x10	0001 0000	020
255	0xFF	1111 1111	377
256	0x100	0001 0000 0000	400
65535	0xFFFF	1111 1111 1111 1111	177777

References

IEEE. IEEE 754-2019 — Standard for Floating-Point Arithmetic. IEEE, 2019.
Knuth, Donald. The Art of Computer Programming, Vol. 2. Addison-Wesley, 1997.
Patterson, David A. and Hennessy, John L. Computer Organization and Design. Elsevier, 2020.
ISO/IEC 9899:2018. C18 — Programming Language C Standard. ISO, 2018.
NIST. FIPS PUB 197 — Advanced Encryption Standard (AES). NIST, 2001.