Binary Converter: Binary, Octal, Decimal, Hex, Text and ASCII

Binary, octal, decimal and hexadecimal are positional systems: each one writes the same value with a different digit set and a different weight for each place. Change the base and the notation changes; the quantity does not.

Binary is the pivot the other three turn on. One hexadecimal digit equals exactly 4 bits (16 = 2⁴); one octal digit equals exactly 3 bits (8 = 2³). Hex and octal are therefore converted by grouping bits, and hex ↔ octal passes through binary.

Text joins the family through the same door. Every character has a numeric code, and that code is then written in one of the four bases. A byte is 8 bits and holds 256 values, 0–255; a nibble is 4 bits. Binary code is the name for bits read as a code rather than as a number; what binary code is covers the distinction in full.

Notation tells you which base you are reading. 0b marks binary, 0o octal, 0x hexadecimal; a leading # marks a hex colour. Hexadecimal is not case-sensitive (FF = ff); iToolHub writes hex digits in uppercase. For the rules behind all of it, read how number-system conversion works.

Most Popular Binary Conversions

• Text to Binary — turn a word or a name into 8-bit bytes
• binary to ASCII converter — read a run of codes as characters
• text to ASCII converter — the code number behind each character
• Binary to Text — the return trip, from bytes back to words
• Binary to Decimal — binary read as an ordinary number
• Hex to Decimal — the most competitively open pair in this family
• Decimal to Hex — the direction colour codes and byte offsets need

All Binary Converters

Every ordered pair in this family has its own page: 25 converters, grouped by what you are starting from. With the guides that explain the methods behind them, the cluster runs to 30 live pages.

Which Converter Do I Need?

Text or ASCII code?

A text converter takes whole strings and gives one byte per character; an ASCII converter takes one code at a time. For whole words, use a text tool such as text to ASCII converter.

Decimal number or decimal ASCII code?

65 as a number is 1000001 in binary; 65 as an ASCII code is the letter A. The tools differ because the frames differ, and decimal to ASCII converter reads codes.

Hex string or hex bytes?

0x2F is one number; 48 65 is a pair of bytes that spell He. Byte pairs belong in the hex text tools, starting with Hex to ASCII.

Octal digits or Unix permission?

755 is an octal number and also a chmod mode; the conversion is the same, the reading is not. Either way the digits go to Octal to Decimal.

The rule that decides is the same for every pair — how number base conversion works.

Conversion Tables

The tables live with the pages that own them.

• ASCII code chart (decimal, hex, octal, binary) — all 128 codes, one row each.
• The master 0–255 table — every value in four bases, on the root document.
• The binary alphabet — A–Z and a–z as 8-bit bytes.

How Number-System Conversion Works

Three method families cover every conversion in this cluster, and each one has a page that teaches it.

• Repeated division is the route out of decimal into another base; Decimal to Binary works it through.
• Positional expansion is the route back into decimal; Binary to Decimal works it through.
• Bit grouping is the shortcut hexadecimal and octal share; Binary to Hex works it through.

The full treatment of both universal methods, with worked examples, lives on how number base conversion works.

Guides

• Number System Conversion — the two universal methods and the master table
• ASCII code chart (decimal, hex, octal, binary) — the reference every code-frame tool points into
• how ASCII, Unicode and UTF-8 differ — why é takes two bytes; the character-frame pages depend on it
• signed binary with two's complement — negative values, for the one pair that needs them
• what binary code is — binary code as distinct from the binary number system

FAQs About Binary Conversion