Convert whole numbers between number systems (binary, octal, decimal, hexadecimal) - locally in your browser, no upload.
Running locally on your device ...
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Your files never left your device
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
Computers compute in binary, programmers often read hexadecimal, and humans think in decimal. When developing, when reading memory addresses, color values or permissions, you constantly switch between these number systems. This tool takes a whole number in one system and outputs it in another - between binary (base 2), octal (8), decimal (10) and hexadecimal (16), in both directions.
You choose the source system and the target system; the input is checked against the allowed digits of the source system. A hex number may thus contain 0-9 and a-f, a binary number only 0 and 1 - if a digit does not fit, the tool says so honestly instead of inventing a wrong result. Negative numbers are allowed. The conversion uses arbitrary-size integer arithmetic, so even very large values are converted exactly and without rounding errors.
The whole calculation runs entirely locally in your browser in pure JavaScript - your input is not uploaded, not stored, and no foreign library is loaded from a CDN. You can download the result as a text file or copy it straight out.
| Input formats | Text input |
|---|---|
| Output format | TXT |
| Batch processing | No |
| Processing | Locally in your browser (JavaScript) |
| File upload | None |
Limitations: The tool converts whole numbers (binary, octal, decimal, hexadecimal); decimals and fractions are not supported. Hex letters are output in lowercase. If a digit does not fit the source system, there is an honest error instead of a wrong result. The arithmetic is arbitrary-size and therefore free of rounding errors.
No. The conversion runs entirely locally in your browser; your input never leaves your device and is not stored.
No, the tool converts whole numbers. Decimals and fractions are not supported.
Yes. The conversion uses arbitrary-size integer arithmetic, so there are no rounding errors as with ordinary floating-point numbers.
If a digit does not fit the chosen source system (such as a 2 in a binary number), the tool reports an honest error instead of a wrong result.