Free Number Base Converter
Convert a whole number between binary, octal, decimal and hexadecimal, or any base from 2 to 36. Type in any box and the rest update as you go. Big numbers stay exact, and it all runs in your browser.
8 bits, fits in a byte
255 in more bases
Convert in four steps.
No convert button, no page reload and no upload. Type a number in any base and every other base updates as you type.
Enter a number
Type a value into any of the four boxes, binary, octal, decimal or hex. Pasting works too, and a 0x, 0b or 0o prefix is understood.
Watch every base update
The other boxes fill in as you type. Big numbers stay exact, because the tool works with whole integers rather than floating point.
Use any base up to 36
Need base 5 or base 32? Set the custom base and read or type your number there, right alongside the usual four.
Copy what you need
Copy any value in a tap. Binary is grouped into nibbles and hex is upper case, so it is easy to read and paste into code.
The four bases, plus any other.
Binary, octal, decimal and hex each get their own box, and the custom base covers everything else from 2 to 36.
Binary (base 2)
Just 0 and 1, the language of circuits and memory. Every bit is a power of two, which is why file sizes, flags and bitmasks are built from it.
Octal (base 8)
Digits 0 to 7, where three bits pack into a single digit. Still seen in Unix file permissions like 755 and in some older systems.
Decimal (base 10)
The everyday base, digits 0 to 9. What people count in, and the one every other base here converts to and from.
Hexadecimal (base 16)
Digits 0 to 9 then A to F, where four bits fit one digit. The compact way to write colours, memory addresses and byte values.
From bitmasks to homework, sorted.
Read a colour or a byte
A CSS colour, a memory address or a register value arrives in hex. Drop it in to see the plain decimal, or the exact bits behind it.
Check a file permission
Turn a Unix permission like 755 from octal into the bits it sets, or work the other way to build the number you need.
Debug a bitmask
See a flag value in binary to know exactly which bits are on, then read the same value straight back in decimal or hex.
Do homework or teach
Computer science courses live in binary and hex. Convert both ways to check an answer or to show the working step by step.
Work with low-level data
Firmware, network protocols and file formats speak in hex and binary. Convert an offset or an opcode without reaching for a calculator.
Shorten a big number
Base 36 packs digits and letters together, a compact way to write large IDs. Convert to and from it in the same place.
Data that has to be exactly right?
Converting one number is easy. Handling identifiers, encodings, bitmasks and binary formats across a whole system, so a value is never truncated or misread, is a different job. That is the kind of software we build at Techliphant, shaped around how your product actually works.
Common questions.
It is a free online tool that rewrites a whole number from one base to another, for example binary to decimal, decimal to hexadecimal, or hex to octal. You type a value in any base, and it shows the same number in binary, octal, decimal, hex and any base you pick from 2 to 36, all at once.
Type or paste your binary digits into the Binary box. The Decimal box updates as you type, so 11111111 in binary reads as 255 in decimal straight away. It works the other way too: type 255 into Decimal and the Binary box shows 11111111.
Enter your number into the Decimal box and read the answer in the Hexadecimal box. For example 255 becomes FF, and 4096 becomes 1000. Hex is shown in upper case, which is the usual style for colours and addresses, and you can copy it in one tap.
They are how code marks the base of a number. 0x means hexadecimal, 0b means binary and 0o means octal, so 0xFF, 0b1111 and 0o17 are all just numbers in those bases. You can paste a value with its prefix and the tool strips it for you.
Yes. It uses exact whole-number arithmetic, so a number with dozens or hundreds of digits converts without any rounding. Ordinary calculators lose precision on large values because they use floating point, but this tool keeps every digit correct.
Any base from 2 to 36. Binary, octal, decimal and hex each have their own box, and the custom base box covers everything in between, such as base 3, base 5, base 12 or base 32. Bases above 10 use the letters A to Z for the extra digits.
Four binary digits, a nibble, map to exactly one hexadecimal digit, so grouping binary into fours makes long strings much easier to read and to line up against their hex value. The grouping is only for display and does not change the number.
This tool is for whole, non-negative integers, which is what base conversion questions almost always involve. It does not take a minus sign or a decimal point. For signed values you would usually work with a bit width and two-complement, which is a separate topic.
A bit is a single binary digit, 0 or 1. A nibble is four bits, which is one hex digit. A byte is eight bits, which is two hex digits and can hold values from 0 to 255. The info strip under the boxes shows how many bits your number needs and whether it fits in a byte or a larger word.
No. Every conversion runs inside your browser, on your own device, in JavaScript. Nothing you type is sent to a server or stored, so it is safe for private or commercial values, and it keeps working even if your connection drops.
Yes, completely. There is no account, no email and no limit on how many numbers you convert. Use it for study, work or personal projects as much as you like.
Private by design: this converter runs entirely in your browser. Every conversion happens on your own device in JavaScript, so nothing you type is uploaded to a server or stored anywhere. That makes it safe for private or commercial values, and it keeps working even if your connection drops.
Ready when you are
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