How does hex shorthand expansion work?

Each single digit is doubled. A 3-digit hex #F80 becomes #FF8800 because F becomes FF, 8 becomes 88, and 0 becomes 00. The same rule applies digit by digit, so the shorthand and full forms always represent the exact same color.

Why does #F80 equal #FF8800 and not #F08000?

Because the rule doubles each digit rather than padding with zeros. Doubling keeps the value proportional: the single digit F is the maximum, so it must map to FF, the maximum byte. Padding with a zero would darken the color incorrectly.

Can shorthand represent every color?

No. Shorthand can only express colors whose channels happen to be a doubled digit, such as 00, 11, 22, up to FF, which is just 16 levels per channel. Arbitrary colors like #3b82f6 have no valid 3-digit shorthand and must stay in full form.

Does it handle 4-digit alpha shorthand?

Yes. CSS allows a 4-digit #RGBA shorthand where the fourth digit is alpha. The tool expands it to the full 8-digit #RRGGBBAA form by doubling all four digits, so #F80a becomes #FF8800AA.

What if I paste a value that is already 6 digits?

The tool detects that it is already in full form and passes it through unchanged, telling you no expansion was needed. Invalid lengths or non-hex characters are flagged with an error message instead.

CSS Hex Shorthand Expander

Expand CSS hex shorthand

CSS lets you write a hex color in a compact 3-digit form, where #F80 is exactly the same color as #FF8800. This tool expands that shorthand — and the 4-digit alpha variant #RGBA — into the full canonical form by doubling each digit, validates the input, and previews the result with a live swatch. It is the quick way to normalize colors before storing or comparing them.

How it works

Expansion is a simple per-digit doubling: every single hex digit is repeated to form a byte. So #F80 expands as F to FF, 8 to 88, 0 to 00, giving #FF8800. The same rule applies to the 4-digit alpha shorthand, where the fourth digit becomes the alpha byte: #F80a becomes #FF8800AA. The tool first strips an optional leading hash, checks that the body is valid hex and a legal length (3, 4, 6, or 8), then either expands the short forms or passes the already-full forms through unchanged.

Example and notes

#abc expands to #aabbcc, and #0f08 expands to #00ff0088. Remember the key trick: doubling keeps the value proportional, which is why #F80 is not #F08000. Shorthand is lossy in reverse — only colors whose channels are doubled digits (16 levels each) can be shortened — so most real-world colors like #3b82f6 simply have no shorthand and must remain in long form.