What is my user agent?

What is a user agent?

A user agent is a string label used by software that is used to identify itself when communicating over a network, such as the Internet. It does this by setting the User-Agent header when making the HTTP request. It does this to help servers tailor their responses based on the user agent that is being provided. This is particularly useful when using a device such as a mobile phone, to which you may be provided with extra mobile features compared to browsing on a desktop device. A blank or malformed user agent can be marked as malicious by some firewall and web application firmware, including Cloudflare.

What is "Mozilla Compatibility" in a user agent string?

The Mozilla compatibility version found in user agent strings is nowadays meaningly data, typically used for historical reasons, which describes that the browser is Mozilla compatible. It is common in almost every browser today with Mozilla/5.0 being the most popular token.

What is the "platform" in a user agent string?

The platform attribute found inside a user agent string describes the native platforms the browser is running on. This can include the hardware model, operating system, CPU, and whether the device is a mobile phone or not. You will likely see Windows, Mac, Linux, or Android as the most popular user agent strings for the platform. It is also possible to include multiple tokens such as the operating system and mobile flag (Android 11; Mobile).

What is the "layout engine" in a user agent string?

The layout engine found in user agent strings describes the software and the version used to render the web page such as Gecko.

What is "browser" in a user agent string?

The browser string in a user agent string describes the browser used such as Chrome, Edge, Firefox, and Safari.

Fix Error 403 disallowed_useragent

The error 403 is an error that typically indicates that the user agent making the request is not allowed or is restricted. HTTP error 403 is the Forbidden response status code that is used by servers to refuse access to a resource. Regardless of your access level, 403 forbidden indicates that re-authenticating will not change your outcome to gaining access to the resource. Here are some common fixes to the error 403 disallowed_useragent problem.

• Make sure your request isn't sending a blank user-agent header
• Update your software (for example the web browser) to the latest version
• Avoid making a request using a bot or automation software
• Review API documentation for any requirements and/or user agent restrictions
• In some cases, there might be a misconfigured server, check with the server owner

iPhone user agent

iPhone mobile devices will typically have a user agent where the version of the iPhone and a "like Mac OS X" flag to determine its use.

Mozilla/5.0 (iPhone; CPU iPhone OS 16_6_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.6 Mobile/15E148 Safari/604.1

iPad user agent

Similar to the format of an iPhone user agent, an iPad will instead have the "iPad" label set as the platform used.

Mozilla/5.0 (iPad; CPU OS 16_6 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/118.0.5993.92 Mobile/15E148 Safari/604.1

Android user agent

There are many Android devices on the market today, but below is an example of such devices, where the platform is normally always Linux.

Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Mobile Safari/537.36

Firefox user agent

Firefox user agent strings tend to be slightly different from the rest, where they use the pre-set label of "Gecko/20100101" to determine they use the Gecko engine, developed by the Mozilla Foundation. The "20100101" label is a fixed string that's used on desktop versions of Firefox. If using Firefox on a mobile the 20100101 flag is replaced with the same version as the software, such as "Gecko/119.0".

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/119.0

Chrome user agent

Google Chrome browsers will tend to follow similar strings as others, in particular displaying the Chrome software version used.

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36

Random user agent string

Looking for a random user agent string to test? Below is an example of a random user agent of a Samsung device running Android 11 using Chrome-based browser, SamsungBrowser.

Mozilla/5.0 (Linux; Android 11; SAMSUNG SM-A705FN) AppleWebKit/537.36 (KHTML, like Gecko) SamsungBrowser/22.0 Chrome/111.0.5563.116 Mobile Safari/537.36