Can I convert a hex value like FF?

Yes, select Hexadecimal as the source base and enter FF (letters are case-insensitive).

Number Base Converter

Convert a number from any base (binary, octal, decimal, hexadecimal) into all other common bases.

Inputs

Results

Try an example

Formula

parseInt(value, fromBase) then converted with toString(base)

Everyday Developer Utilities Explained: Encoding, Number Bases, and Timestamps

What Base64 encoding, hexadecimal, and Unix timestamps actually represent, and why they're used instead of plain text.

How Base64 Encoding Actually Works

What Base64 does to text and binary data, why it exists, and why it's not a form of security.

Unix Timestamp Converter

Convert between Unix timestamps and human-readable dates.

Base64 Encoder / Decoder

Encode text to Base64 or decode Base64 back to text.

URL Encoder / Decoder

Encode text for safe use in a URL, or decode a URL-encoded string.

UUID Generator

Generate a random version 4 UUID.

CSS Unit Converter

Convert between px, rem, and em CSS units.

Aspect Ratio Calculator

Calculate the missing dimension to preserve an aspect ratio.