# 11100: Invalid URL format

Log Type: APPLICATION

Log Level: ERROR

## Description

This error occurs when you configure or submit a URL that isn't in a valid absolute format. Use a fully qualified `http://` or `https://` URL that Twilio can reach over the public Internet for phone number webhooks, outbound call instructions, and TwiML callback URLs.

### Possible causes

* You configured an invalid webhook URL for a phone number.
* You passed an invalid URL in an outbound call request.
* You used an invalid URL in a `<Play>` or `<Redirect>` verb body.
* You provided an invalid URL for a verb `action` attribute.
* You didn't provide a URL for the `<Record>` verb `action` attribute when modifying a live call.
* You included unsupported characters in the authentication portion of the URL.

### Possible solutions

* Submit a fully qualified URL that includes the protocol, hostname, path, and properly URL-encoded query parameters.
* Make sure the endpoint is publicly reachable. Webhook requests can't be sent to a private or local URL directly.
* If you are creating an outbound call, provide a valid absolute `Url` or send `Twiml` directly instead of having Twilio fetch instructions from a URL.
* Review any `sms_url`, `voice_url`, or verb `action` value you configured and remove malformed URL components or unsupported authentication characters.
* When you test locally, expose your application through a public tunnel and use the generated public HTTPS URL.

#### Additional resources

* [Webhooks Overview](/docs/usage/webhooks/webhooks-overview)
* [IncomingPhoneNumber resource](/docs/phone-numbers/api/incomingphonenumber-resource)
* [Call resource](/docs/voice/api/call-resource)