Understanding URL Validation Errors

URL validation errors occur when a web application fails to correctly validate URLs entered by users. Proper validation is crucial to prevent security vulnerabilities, ensure data integrity, and improve user experience. Below are three practical examples of common URL validation errors:

1. Missing Protocol in URL

In many web applications, users are required to input a website URL. If the application does not enforce the inclusion of a protocol (http:// or https://), it may result in a malformed URL that leads to errors when trying to access the site.

Consider a scenario where a user inputs a URL without specifying the protocol:

• Example: www.example.com

In this case, the application might attempt to access the URL as if it were a complete web address, resulting in an error since the browser does not know how to interpret the input.

Notes:

• To avoid this error, ensure that the input field is configured to require a protocol or automatically prepend http:// if the user omits it.
• Consider implementing a regex pattern that validates the full structure of a URL, including the protocol.

2. Invalid Characters in URL

When users input URLs, they may inadvertently include invalid characters, which can lead to errors during validation. For instance, spaces or special characters that are not permitted in URLs can cause issues.

Imagine a user trying to submit the following URL:

• Example: http://example.com/my page?query=1&sort=asc

In this example, the space between