What is a User Agent? Some Examples of User Agents
In the context of the web, a user agent is a software application that acts on behalf of a user to interact with a website or web server. It typically identifies itself to the server with a specific string of text known as the user agent string.
Web browsers, such as Chrome, Firefox, Safari, and Internet Explorer, are examples of user agents. When a user visits a website using a web browser, the browser sends a request to the web server that includes a user agent string identifying the browser and its version.
Other examples of user agents include web crawlers, search engine bots, and other software applications that interact with web servers. Each user agent may have different capabilities and behaviors, which can affect how a website is displayed or interacted with.
The user agent string can be used by web servers to customize the content or layout of a website based on the capabilities and preferences of the user agent. For example, a website may display a mobile-friendly version of its content when accessed by a user agent string indicating a mobile device.
However, the user agent string can also be modified or faked, so it's not always a reliable indicator of the actual user agent or device being used to access the website.
Browsers
Firefox 112.0
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/112.0
Chrome 112.0
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36
Mobile Safari 15.0
Mozilla/5.0 (iPhone; CPU iPhone OS 15_6_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.0 Mobile/15E148 Safari/604.1
Google App for iOS
Mozilla/5.0 (iPhone; CPU iPhone OS 14_8 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) GSA/248.1.504392274 Mobile/15E148 Safari/604.1
Edge 112.0
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36 Edg/112.0.1722.68
Opera 98.0
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36 OPR/98.0.0.0
Safari 537.36
"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.157 Safari/537.36"
Search Engines
Googlebot/2.1
Smartphone: Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5X Build/MMB29P) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/W.X.Y.Z Mobile Safari/537.36 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)
Desktop: Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Googlebot/2.1; +http://www.google.com/bot.html) Chrome/W.X.Y.Z Safari/537.36
Rarely: "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"
FeedFetcher-Google
"FeedFetcher-Google; (+http://www.google.com/feedfetcher.html)"
Google-Structured-Data-Testing-Tool
"Mozilla/5.0 (compatible; Google-Structured-Data-Testing-Tool +https://search.google.com/structured-data/testing-tool)"
Bingbot/2.0
"Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)"
Sogou web spider/4.0
"Sogou web spider/4.0(+http://www.sogou.com/docs/help/webmasters.htm#07)"
YandexBot/3.0
Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)
Note: Each search engine has more robots
Other bots
"WhatsApp/2.17.52 i"
Twitterbot
"Twitterbot/1.0"
Validator w3.org
"Validator.nu/LV http://validator.w3.org/services"
SEO-tools
"Mozilla/5.0 (compatible; AhrefsBot/6.1; +http://ahrefs.com/robot/)"
"Mozilla/5.0 (compatible; SemrushBot/6~bl; +http://www.semrush.com/bot.html)"
"Mozilla/5.0 (compatible; MJ12bot/v1.4.8; http://mj12bot.com/)"
Spam, Douwloaders and other
"Python-urllib/2.7"
"Mozilla/3.0 (compatible; Indy Library)"
Apache-HttpClient/4.5.2 (Java/1.8.0_361)