Verified no-login tool
Pick base, type number, read all.
Pick the input base — decimal, binary, octal or hexadecimal.
Type your number.
All four base conversions appear instantly.
Copy any result with one click.
Built for speed, privacy and reliability — on any device.
Decimal, binary, octal and hexadecimal — all shown simultaneously with copy buttons.
Type a number in any base and all conversions update instantly.
Invalid digits for the selected base are flagged with a clear error.
Conversion runs locally — nothing is sent anywhere.
No account, no limits.
Different ways to represent the same number. Decimal (base 10) uses 0-9, binary (base 2) uses 0-1, octal (base 8) uses 0-7, and hexadecimal (base 16) uses 0-9 plus A-F.
Hex is compact and maps cleanly to binary — one hex digit represents exactly 4 bits.
Each base has valid digits. Binary only allows 0 and 1; octal only 0-7. If you type 9 in binary mode, it is invalid.
No. Conversion runs entirely in your browser.
The tool works in all modern browsers including Google Chrome, Mozilla Firefox, Microsoft Edge, Safari and Opera. We recommend keeping your browser up to date for the best experience.
Decimal, binary, octal, hex — all at once