Comparing Authentication Methods

In proxying, IP address authentication is one of two methods for authenticating to a proxy server. The other is username:password authentication. Many proxy services support configuration of the proxy host with Basic Access authentication as well as IP address authentication. Although both methods increase your security, each authentication type has advantages and disadvantages. This article discusses the differences between IP authentication and username:password , and the pros and cons of each method.

Username:Password Authentication

Username:password authentication is the most frequently used HTTP proxy authentication method. Most HTTP client libraries support it.

The method requires you to log in with a username and password, ensuring that only authorized users have access to sensitive information. The credentials, created with the Basic Access authentication method, are passed in with an HTTP request in the Proxy-Authorization header.

When to Use

For HTTP, you can generally authenticate with the Proxy-Authorization header using the Basic access authentication method. Most HTTP client libraries support this authentication method.

With HTTPS URLs, Python Requests supports username:password authentication, whereas most other libraries do not. You’ll find details in Proxy Authentication.


You need only one username and password to connect to all the proxies you have.A username and password allow you to access your proxies from any location, especially useful if you frequently travel or access your proxies from more than one location. You can include the username and password in your scripts for data requests.


This method of authentication only provides basic access authentication – a lower level of security than IP authentication. That’s because it is not encrypted, it is only encoded, so it’s possible that someone in the middle could intercept and decode it.

And, of course, you have to remember your password. Easy-to-remember passwords are not recommended, since they’re also easier for hackers to figure out. A password manager like 1Password that can generate strong random passwords provides good controls..

Another disadvantage is that the Proxy-Authentication header is not always passed to the proxies correctly for HTTPS requests. Even many programming language clients don’t do that. Python Requests is one of the few that can do it correctly.

IP Authentication/Whitelisting

IP Authentication/whitelisting is the easiest and most secure authentication method for proxying. When you add your IP address to your proxy service via dashboard or API, you are “whitelisting” that address with the proxy.

When to Use

For HTTPS requests, IP authentication is the most reliable method. This includes HTTPS requests with web browsers or Selenium.


This method allows you access to your proxies without the use of a password or username. Instead of sending a Proxy-Authorization header, you use the IP address assigned to you by your Internet service provider. Whitelisting is a great timesaver, especially if you have a lot of proxies.

Configuring for your browser or scraping client is simple. Just add your IP address for authentication to the proxy service. In many proxy services, you can do that either on a dashboard or through the service’s API.

For HTTPS requests with web browsers or Selenium, IP authentication is the most reliable and easiest method. Since there is no Proxy-Authorization header, it's guaranteed to work without issues.


Since access to your proxy is dependent upon the IP address where it was authenticated, you can only access your proxies from that IP address. This makes whitelisting less desirable if you frequently travel or access your proxies from different locations.

Some Internet service providers use a dynamic IP system that allows them to change your IP address without warning for security reasons. Whenever this occurs, you would need to authenticate a new IP address for your proxy.

Repeated failed login attempts can cause IP address blocks, which are usually temporary. But you’ll need to wait until the ban expires even if an IP update was performed during a ban.

Unlike username:password authentication, a proxy system does not allow the same IP to be authenticated for multiple accounts.

ProxyMesh implements the HTTP protocol – supported by practically all client software – and both username:password and IP address authentication, making configuration simple. It can be installed on any of the major computer platforms and configured for HTTP requests in most popular programming/scripting languages. Using the CONNECT method, you can also send encrypted requests over HTTPS.

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