What is a User Agent? Complete Guide 2026 & Browser Checker

I am sure you already know that websites track our activity using cookies.

But they also have a lot of other ways to track us. One of them is through your user agent, which is a string that your browser shares with websites on each visit.

The story isn’t that simple, though, because the actual purpose of the user agent is innocuous (harmless, if you will). It was not made for tracking purposes. Websites just exploit their potential to track you.

In this article, you’ll learn about user agents in depth. You’ll learn:

• What is a user agent
• What is your user agent right now
• How people hide their real user agents
• And the professional way of hiding your user agent

What is a User Agent?

Every time you want to visit a website, your browser sends a request to that website’s server. This request is made using a piece of text known as an HTTP header. This piece of text contains a string called the user agent.

The user agent string informs the web server about your software, your operating system, the specific version of the browser you are using, and, in certain cases, your device’s model.

For example, take a look at this user agent string for the Chrome browser running on a Google Pixel 9 phone:

Mozilla/5.0 (Linux; Android 16; Pixel 9) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.12.45 Mobile Safari/537.36

The basic function of the user agent string is content negotiation. When the web server sees that the request is coming from an Android phone, it loads the version of the website on your screen made for that specific Android phone.

In case you’re using an old browser that might struggle with loading new features, the web server sends a simpler version of the page so things do not break.

Components of a User Agent

All the elements of the user agent have a function and a history. Here’s what each one is called:

• Legacy token: The legacy token in almost all user agent strings is Mozilla/5.0. Back in the day, some websites only worked for the popular Mozilla browser. Other browsers started including this in their UA strings to stay compatible.
• System details: This is the section in parentheses right after the legacy token. In the UA string you saw above:
  • Linux and Android 16 are the operating systems
  • Pixel 9 is the device model
• Rendering engines: This section mentions the software responsible for drawing the website on your screen. Most Chromium-based browsers (and Safari) use AppleWebKit/537.36 for compatibility reasons.
• Compatible rendering engines: This is the part after the rendering engine. It is another nod to the past and included for compatibility reasons.
• Browser & version: Shows the browser in use and its version. You might also see Safari mentioned at the end for compatibility reasons.

What is My User Agent Right Now?

Since you have now got the answer to your question, “What is a user agent?”, you might be thinking to yourself, “What is my user agent?”

Luckily, looking up your user agent is extremely easy.

Here are three methods of finding your user agent.

1. Use a Simple Search Engine Query

A search engine is also a kind of website, and your browser also shares the UA string with it for each search query. So simply ask the search engine about your user agent string.

Google Search showed me my user agent as the very first result when I typed “my user agent.” If this doesn’t work for you, try a more descriptive query such as “what is my user agent.”

Note: This method might not work on all search engines. See the next method for finding your user agent.

2. Check the Browser Console Directly

This is the proper and most accurate way of looking up your browser user agent.

Follow these steps:

1. Open Chrome and press F12 to open the developer tools, if you’re using Windows. If you’re on a Mac, press Cmd + Option + J to open the console. A panel will open up on the side of your screen.
2. Click the tab that says Console. At the very bottom of the Console tab, there’ll be an area where you can type.
3. Type navigator.userAgent in that area and hit enter. If you’re doing it for the first time, you will have to manually type allow pasting before pasting any text. Or you can just type out the command if the console is not allowing copy/pasting.

3. Run a Browser Fingerprint Check using Iphey

The two methods you saw above will definitely tell you what your user agent is and give you some basic details. What they won’t tell you is whether your user agent actually holds up. For that, there’s a free tool called Iphey.com.

Apart from giving you your user agent details, Iphey gives you detailed information about your browser, hardware, software, location, etc. It runs the following leaks and tests:

• Fingerprint Check
• IP Check
• VPN Check
• Bot Check
• DNS Leak Test
• IP Blacklist Test

So if you ever spoof your user agent, Iphey is the easiest and by far the quickest way to check whether your disguise actually works or falls apart on closer inspection.

Why and Who Manages Different User Agents?

While the user agent’s basic function is content negotiation, as stated earlier, websites also use it to track you across the web for advertising purposes.

These websites log your user agent and other details of your software and hardware to build a comprehensive profile of you. This process of profiling is called browser fingerprinting, and privacy-conscious users don’t like it.

This leads those people to customize their user agent strings to prevent websites from knowing their actual user agent. The practice of faking your user agent is called user agent spoofing.

But privacy is not always the reason why people fake their user agents.

Some also maintain multiple user agents to be able to run multiple accounts on a platform without letting that platform know those accounts are owned by one person. Because if they access all their accounts using a single user agent, their accounts can get banned by platforms that prohibit users from having multiple accounts.

Another group of people spoofs their user agents when scraping data from websites using bots. Bots have a distinct user agent, and most websites that are against web scraping block them for that. So users have to give their bots a realistic UA to avoid blocking.

Why User-Agent Changers Get You Banned

You read about user agent spoofing, but did you wonder what tool or technique people use to achieve that?

Most people just go to the Chrome store and download a simple user agent switcher. These extensions give them a list of user agents for different devices and browsers to choose from.

However, this method can get you banned because websites are much smarter than they were years ago.

As I mentioned earlier, your browser sends a lot of information to websites along with the user agent. If you fake your operating system in your user agent, a website can still retrieve your actual operating system from other system attributes shared with it by your browser.

Websites can also sense technical contradictions from your browser’s behavior.

For example, if your user agent says you are on a Windows PC, but your browser supports specific touch-screen features that only exist on iPhones, websites will be able to see that you are spoofing your user agent.

So, any technique that involves spoofing only the user agent string can lead to bans. You need to implement a comprehensive spoofing technique to hide your identity completely. And yes, solutions like that exist. They are called antidetect browsers, and Gologin is a leading example.

Manage User Agents Natively via Gologin

Gologin is an antidetect browser that lets you build multiple different identities to manage multiple accounts and perform tasks like web scraping and multi-account management.

Gologin doesn’t just patch the text of your user agent string and call it a day (like those user agent switcher extensions do). Gologin runs on a custom-built browser engine called Orbita, which changes your user agent natively, deep from within the browser’s core binary.

It allows you to not only customize your user agent but also manually edit your entire browser fingerprint. If you don’t have time for manual editing, Gologin can also generate entire random fingerprints for you.

In case you’re wondering, here’s what makes it all work:

• Total fingerprint sync: When you select a new user agent in Gologin, let’s say, an iPhone or a Windows laptop, the software automatically recalibrates all the deep browser variables to match that particular signature. Now this includes your Client Hints, canvas rendering paths, and hardware concurrency limits. This way, there’s absolutely no contradiction left for a website to catch/flag.
• Automated profile longevity: Since every browser profile in Gologin has a perfectly consistent and natural device identity, you can do multi-accounting at scale without triggering any fraud alerts.
• Sterile headless automation: If you’re a developer who works with LLMs or Python automation frameworks, you can use Gologin’s local API to safely run headless scripts with perfectly matched, stable user agents.

In short, Gologin aligns your user agent with your hardware and location data so you never trigger any suspicious mismatches. Web scrapers are also big-time users of Gologin.

Sign up for Gologin today and try it free for 7 days.

FAQs

What is a user agent?

A user agent is a string of text your browser sends to websites to request the correct version of the website made for your specific device/operating system/browser.

Can I safely change my browser user agent with an extension?

Yes, user agent switcher extensions allow you to change your user agent. However, websites will still be able to detect the correct information about your system from other information your browser shares with the websites. Only antidetect browsers like Gologin offer a way to customize all attributes of your browser fingerprint and build a truly different identity.