Does my data get uploaded anywhere?
No. Everything runs locally in your browser and nothing is sent to a server.
Is this free to use?
Yes. It is completely free, with no account, no signup, and no usage limits.
Does it work on a phone?
Yes. The page runs in any modern mobile browser, on iPhone and Android alike, with no app to install.
How do I convert a hex colour into RGB numbers?
Split the six digits into three pairs and convert each one. #1E90FF becomes 1E, 90, FF, which is 30, 144 and 255, giving rgb(30, 144, 255). You can paste the three pairs separated by spaces and get all three decimals at once.
What does the 0x prefix mean?
It is the C-style marker telling a compiler that the digits that follow are hexadecimal rather than decimal. It is not part of the value, and this tool strips it, so 0x1F and 1F both convert to 31.
Why does 1E90FF give 2,003,199?
Because you asked it to read the whole string as one number, and 1E90FF as a single 24-bit value is 2,003,199. As a colour, those same bits are three separate bytes, so split them into 1E, 90 and FF before converting.
Is hex input case-sensitive?
No. Upper and lower case letters are treated the same, so DEADBEEF and deadbeef both give 3,735,928,559. Only characters outside 0-9 and a-f are rejected, and the error message names the character that failed.
Why does FFFFFFFF give 4,294,967,295 and not -1?
Because the tool converts an unsigned magnitude with no assumed width. Two's complement is a convention that only exists once you fix the number of bits. If you know the value is a signed 32-bit integer, subtract 4,294,967,296 to get -1.