Convert values between binary, octal, decimal, hexadecimal and base36.
Updated
Quick start
Choose input base and get multi-base outputs.
Provide value and source base.
Tool checks digit validity for selected base.
Use converted values in binary/octal/decimal/hex/base36.
In-depth guide
A number's value is the same whatever base you write it in — only the notation changes. Decimal 255 is FF in hex, 11111111 in binary, 377 in octal. This tool converts integers across all these bases instantly and locally in your browser.
Binary (base 2) is how hardware stores everything. Hexadecimal (base 16) is the compact human-friendly view of binary — one hex digit equals four bits — used for colours, memory addresses and byte dumps. Octal (base 8) survives in Unix file permissions, and base 36 (digits plus A–Z) is handy for short alphanumeric IDs.
ff and FF are the same hex value.Conversion uses JavaScript's BigInt internally, so very large integers convert exactly without the rounding errors you would hit with floating-point numbers. This release handles integers only — fractional values such as binary fractions are not yet supported.
All conversion happens in your browser — the numbers you enter are never uploaded.
Use this tool for quick browser-based work when you need an answer or output immediately. Use a dedicated application or automated workflow when you need bulk processing, approvals, or repeatable production rules.
Yes. Conversion uses BigInt internally, so very large integers convert exactly without floating-point rounding errors.
Not in this version — it supports integer conversion only.
Yes. Input is normalised case-insensitively, so ff and FF are the same hex value.
Binary (2), octal (8), decimal (10), hexadecimal (16) and base 36, which uses the digits 0–9 plus A–Z.
One hex digit maps exactly to four bits, making it a compact, human-readable way to express binary data like colours and memory addresses.
Yes. Everything runs in your browser — the numbers you enter are never uploaded.
Keep exploring
Hand-picked utilities that pair well with the one you're on — all free, client-side, and zero-signup.
Convert image files to Base64 data URLs directly in your browser.
Convert common HTML content into clean Markdown text.
Convert decimal values to canonical Roman numerals and validate Roman inputs with strict subtractive rules.
Shrink PDF file size without uploading to a server.
Body Mass Index with metric / imperial inputs and WHO category bands.
Combine multiple PDFs into one in your browser.
Split a PDF by pages or page ranges, download as zip.