Can I use an at symbol (@) inside URLs?

Is it safe to use an @ symbol as part of a user? For example, a possible URL would be http://example.com/@dave.

The idea is that, nowadays, users are commonly called "@user", so why not make the user page "@username"?

Percent-encoded …

You can use the @ character in HTTP URI paths if you percent-encode it as %40.

Many browsers would display it still as @, but e.g. when you copy-and-paste the URI into a text document, it will be %40.

… but also directly

Instead of percent-encoding it, you may use @ directly in the HTTP URI path.

See the syntax for the path of an URI. Various unrelated clauses aside, the path may consist of characters in the segment, segment-nz, or segment-nz-nc set. segment and segment-nz consist of characters from the pchar set, which is defined as:

pchar = unreserved / pct-encoded / sub-delims / ":" / "@"

As you can see, the @ is listed explicitly.

The segment-nz-nc set also lists the @ character explicitly:

segment-nz-nc = 1*( unreserved / pct-encoded / sub-delims / "@" )

So, a HTTP URI like this is totally valid:

http://example.com/@dave

Example

Here is an example Wikipedia page:

• link
• copy-and-paste: http://en.wikipedia.org/wiki/%22@%22_%28album%29

As you can see, the ", (, and ) characters are percent-encoded, but the @ and the _ is used directly.

Can you use the @-symbol in a URL? - Yes, you can!

Note that that @-character, hexadecimal value 40, decimal value 64, is a reserved characters for URI's. It's usage is for things like email-addresses in mailto:URI's, for example mailto:[email protected] and for passing username and password information on a URI (which is a bad idea, but possible): http://username:[email protected]

If you want a URL that has an @-symbol in a path you need to encode it, with so called "URL-encoding". For example like this: http://somewhere.foo/profile/username%40somewhere.foo

All modern browsers will display this as http://somewhere.foo/profile/[email protected], and will convert any typed in @-sign to %40, so it's easy to use.

Many web-frameworks will also help you either automatically, or with helper-functions, to convert to and from URL-encoded URL's.

So, in summary: Yes, you can use the @-symbol in a URL, but you have to make sure it's encoded, as you can't use the @-character.

In the RFC the following characters:

* ' ( ) ; : @ & = + $ , / ? % # [ ]

are reserved and:

The purpose of reserved characters is to provide a set of delimiting characters that are distinguishable from other data within a URI.

So it is not recommended to use these characters without encoding.