URL Protocol Validator

Technical Specifications & Platform Limits

Step-by-Step Workflow

Practical Real-World Use Cases

Frequently Asked Questions

Does a syntactically valid URI scheme guarantee that the link will function on a user device?

No, syntactic validity does not guarantee operational execution or reachability. While this tool verifies that a URI strictly complies with its corresponding RFC standard, successful execution depends entirely on whether the client operating system possesses a registered application capable of handling that scheme. For example, a valid mailto or tel link will fail to trigger an action if the host device lacks a configured default email client or telephony hardware.

Why does the validator recommend the E.164 international format for tel URI telephone links?

The E.164 format standardizes telephone numbers with a leading plus sign followed by the country code, national destination code, and subscriber number. When a user taps a local phone number without a country code on a mobile device, the operating system may fail to route the call properly, especially when the user is roaming internationally or using a voice-over-IP application. Specifying +18005550199 rather than 800-555-0199 ensures unambiguous international carrier routing.

What are the common syntax mistakes that invalidate mailto email URI links?

Common mailto errors include omitting the recipient address, including unescaped spaces or special characters in query parameters, and failing to percent-encode reserved delimiters. According to RFC 6068, parameter values like subject and body must use standard percent-encoding where spaces are converted to %20 rather than plus symbols. Additionally, multiple recipient addresses must be separated by commas rather than semicolons, as semicolons violate the official mailto grammar.

How does the validator evaluate transport security for web and socket protocols?

The engine checks the transport security characteristics of standard network protocols by comparing unencrypted schemes against their TLS-encrypted equivalents. When an http or ws scheme is detected, the validator issues a security warning explaining that data transmitted over unencrypted connections is vulnerable to eavesdropping and man-in-the-middle tampering. It recommends adopting https (RFC 9110) or wss (RFC 6455) to protect data integrity and user privacy.

Are my validated phone numbers, email addresses, or magnet links sent to external servers?

No. All URI string parsing, regular expression matching, component extraction, and RFC compliance evaluations occur strictly within your local browser memory using client-side JavaScript. No telephone numbers, email addresses, message drafts, or torrent hashes are transmitted across the internet, logged on remote servers, or shared with analytics systems. You can safely inspect private internal and customer-facing URIs.