TOOL · CALCULATOR
Number base converter
Type a number in binary, octal, decimal or hexadecimal and the other three bases show up instantly, ready to copy. An ASCII table comes along for quick reference.
ASCII table (32–126)
decimal · hexadecimal · character
Processed in your browser — your files never leave your computer.
How it works
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Type the number
In the "Number" field, type an unsigned integer. Paste it as it came from code: prefixes like 0x and 0b, spaces and underscores are all accepted.
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Check the source base
In the "Source base" selector, say which base your input is in: binary (base 2), octal (base 8), decimal (base 10) or hexadecimal (base 16). Decimal is the default.
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Read and copy the other three
The remaining three bases appear live, with binary and hexadecimal grouped in blocks of 4 for easier reading. The "copy" button next to each one puts the clean value on your clipboard.
Frequently asked questions
What is binary, anyway?
It is how computers count: only 0 and 1, because deep down everything is a switch that is on or off. We count in tens (ten fingers); computers count in twos. The number 5, for instance, becomes 101 in binary — one 4, no 2 and one 1.
And hexadecimal — what is it for?
Base 16: it uses 0–9 and then A–F (A is 10, F is 15). Programmers like it because it is compressed binary — each hex digit maps to exactly 4 bits. That is why web colors are written like #FF0000: red at full blast.
Can I paste "0x1F" straight from code?
Yes. The tool accepts the prefix of the chosen base (0b for binary, 0o for octal, 0x for hexadecimal) and ignores spaces and underscores — "1010 0001" and "0b1010_0001" work the same.
Why does the binary show spaces in the middle?
Just readability grouping, 4 digits at a time from the right — same reason we write 1,000,000 with commas. When you copy, the value goes out clean, no spaces.
Is there a size limit?
Any integer from 0 up to 18,446,744,073,709,551,615 — the famous 2⁶⁴ − 1, the largest unsigned 64-bit number. Beyond that, the tool tells you. Negatives and decimals are out: it is an integer converter.
What is the ASCII table at the bottom for?
Quick reference: characters 32 through 126 with their codes in decimal and hexadecimal. Handy when you are decoding bytes, escaping characters or learning how computers store text.