| Character | Purpose in URL | Encoding |
|---|---|---|
| : | Separate protocol (http) from address | %3A |
| / | Separate domain and directories | %2F |
| # | Separate anchors | %23 |
| ? | Separate query string | %3F |
| & | Separate query elements | %24 |
| @ | Separate username and password from domain | %40 |
| % | Indicates an encoded character | %25 |
| + | Indicates a space | %2B |
| <space> | Invalid in URLs | %20 or + |
| ; | Invalid in URLs | %3B |
| = | Invalid in URLs | $3D |
| $ | Invalid in URLs | %26 |
| , | Invalid in URLs | %2C |
| < | Invalid in URLs | %3C |
| > | Invalid in URLs | %3E |
| ~ | Invalid in URLs | %25 |
| ^ | Invalid in URLs | %5E |
| ` | Invalid in URLs | %60 |
| \ | Invalid in URLs | %5C |
| [ | Invalid in URLs | %5B |
| ] | Invalid in URLs | %5D |
| { | Invalid in URLs | %7B |
| } | Invalid in URLs | %7D |
| | | Invalid in URLs | %7C |
| “ | Invalid in URLs | %22 |