| FILTER_VALIDATE_IP | Check whether the given IP is valid or not |
| FILTER_VALIDATE_EMAIL | Check whether the email is valid or not |
| FILTER_VALIDATE_INT | Check whether the value is Integer or not |
| FILTER_VALIDATE_FLOAT | Check whether the value is float or not |
| FILTER_VALIDATE_URL | Check whether the url is valid or not |
| FILTER_SANITIZE_SPECIAL_CHARS | It Escapes special characters like &,< etc |
| FILTER_CALLBACK | It can be used to call a user defined function to filter the value |
| FILTER_SANITIZE_STRING | Strip tags and encode special characters |
| FILTER_SANITIZE_STRIPPED | Strips or encodes unwanted characters |
| FILTER_SANITIZE_ENCODED | Encode special characters |
| FILTER_SANITIZE_EMAIL | Remove all illegal email characters |
| FILTER_SANITIZE_NUMBER_INT | Remove all illegal integer characters |
| FILTER_SANITIZE_NUMBER_FLOAT | Remove all illegal characters from a float number |
| FILTER_SANITIZE_MAGIC_QUOTES | It adds slashes before quotes |
| FILTER_UNSAFE_RAW | Encode special characters |
| FILTER_VALIDATE_BOOLEAN | Return TRUE for “true”, “1”, “on” and “yes”, FALSE for “0”, “false”, “off”, “no”, and “”, NULL otherwise |
| FILTER_SANITIZE_URL | Remove all unwanterd characters form a URL |