What pop-up ads are and why they appear
A pop-up ad is a window that opens on top of the website or app you are using, usually without you clicking anything to make it appear. It shows an advertisement — often for products, services, or fake security warnings — and blocks your view of what you were actually trying to read or do.
Pop-ups exist because advertisers pay websites to display them. Some websites use pop-ups as their main way to make money. Others use them sparingly. A few websites use fake pop-ups that look like system warnings but are actually just ads trying to trick you into clicking them or downloading something.
Pop-ups are different from banner ads that sit on the side or top of a page — those stay in one place and do not cover your content. Pop-ups deliberately interrupt you, which is why they are so effective at getting clicks, and why so many websites use them.
Key Takeaways
- Most web browsers have a built-in pop-up blocker that you can turn on in settings, and it stops the majority of pop-ups without any extra software.
- Browser extensions like uBlock Origin or Adblock Plus add a second layer of blocking and also remove banner ads and video ads from websites.
- On your phone, the built-in browser pop-up blocker usually works, but switching to a different browser app sometimes helps if one browser lets more through.
- Fake security warning pop-ups are designed to scare you into clicking — closing them by pressing Escape or clicking the X button is always safe, and your device is not actually infected.
- If a pop-up asks for your password or credit card information, close it when ready and never enter personal data into a pop-up window.
Turning on your browser's built-in pop-up blocker
Every major web browser — Chrome, Firefox, Safari, and Edge — comes with a pop-up blocker already installed. On most browsers it is turned on by default, but if you are seeing a lot of pop-ups, it may have been turned off or the setting may have changed.
On Chrome: Click the three vertical dots in the top right corner, select Settings, then click Privacy and Security on the left side. Look for "Pop-ups and redirects" and make sure it says "Blocked" next to it. If it says "Allowed", click it and change it to "Blocked".
On Firefox: Click the three horizontal lines in the top right, select Settings, then click Privacy & Security on the left. Scroll down to Permissions and look for "Block pop-up windows". Make sure the checkbox next to it is checked.
On Safari (Mac): Click Safari in the top menu bar, select Settings, then click Security. Look for "Block pop-up windows" and make sure it is checked.
On Edge: Click the three dots in the top right, select Settings, then click Privacy, search, and services on the left. Scroll down to Security and look for "Block pop-ups". Make sure the toggle is turned on.
Using browser extensions to block more ads
Browser extensions are small programs that add features to your browser. Some extensions block not just pop-ups but also banner ads, video ads, and tracking code that follows you across websites. The most common ones are uBlock Origin, Adblock Plus, and AdGuard.
To add an extension, go to your browser's extension store. In Chrome, click the puzzle piece icon in the top right corner, then click "Manage extensions", then click "Open Chrome Web Store". Search for "uBlock Origin" or "Adblock Plus", click the extension name, and click the blue "Add to Chrome" button. The extension will install in seconds and start working when ready.
In Firefox, click the three lines in the top right, select Add-ons, then click Extensions. Search for the extension you want, click it, and click "Add to Firefox". In Safari, extensions work differently — you read them from the App Store, not from within Safari itself.
Extensions do not slow down your browser noticeably, and you can turn them off on specific websites if a site does not work properly with them turned on. Right-click the extension icon and look for an option to disable it on that site.
Stopping pop-ups on your phone or tablet
Mobile browsers have pop-up blockers too, but they work slightly differently than on a computer because phone screens are smaller and pop-ups are more disruptive.
On iPhone or iPad: Open Safari, tap the three lines at the bottom right, tap Settings, then scroll down and look for "Block Pop-ups". Make sure the toggle is turned on. If you still see pop-ups, try switching to a different browser app like Chrome or Firefox, which sometimes block pop-ups more aggressively.
On Android: Open Chrome, tap the three dots in the top right, tap Settings, then tap Site settings. Look for "Pop-ups and redirects" and make sure it is blocked. If you are using a different browser, look in its settings for a similar option.
On phones, pop-ups often come from the websites you visit rather than from ads served by the browser itself. If a website is full of pop-ups, the best solution is to stop visiting that website — there are usually better alternatives with fewer interruptions.
Recognizing and closing fake security warning pop-ups
Some pop-ups pretend to be system warnings from your device or antivirus software. They say things like "Your device is infected" or "Click here to scan for viruses" or "Your password has been compromised". These are almost always fake advertisements designed to scare you into clicking.
Real security warnings from your actual operating system or antivirus software do not appear as pop-ups on websites. They appear in your system settings or as notifications from the actual software you installed. If a pop-up on a website is warning you about your device, it is fake.
To close a fake warning pop-up, press the Escape key on your keyboard, or look for a small X button in the corner of the pop-up and click it. Do not click any button that says "Scan", "Fix", "read", or "Protect" — those buttons are what the fake ad wants you to click. If the pop-up will not close, close the entire browser tab or window instead.
Your device is not infected just because a pop-up said so. Closing the pop-up is completely safe. If you are worried about actual malware, run a scan with your real antivirus software from your system settings, not from a pop-up.
What to do if a pop-up asks for personal information
Never enter your password, credit card number, Social Security number, or any other personal information into a pop-up window. Legitimate companies do not ask for sensitive information through pop-ups.
If a pop-up asks you to log in or enter payment information, close it when ready by pressing Escape or clicking the X. Then, if you actually need to access that service, go directly to the company's official website by typing the address into your browser yourself — do not click any link in the pop-up.
Pop-ups that ask for information are usually phishing attempts, which means someone is trying to steal your data. Closing them is always the right choice. If you accidentally entered information, change your password for that service as soon as you can.
Why some websites still show pop-ups even with a blocker on
Some websites are designed to get around pop-up blockers, or they use pop-ups that are technically not pop-ups — they are just boxes that appear on the page itself and look like pop-ups. A pop-up blocker can only stop actual pop-up windows, not fake ones that are just part of the website's design.
If a website shows you a box asking you to sign up for a newsletter or create an account, and it covers the content, that is usually not a true pop-up — it is just part of the website. You can usually close it by clicking an X button or clicking outside the box.
Some websites also show pop-ups only to visitors who do not have an account, or only on the first visit. If you create an account or visit the site again, the pop-ups may stop. If a website is too full of interruptions, it is usually worth finding a different source for the same information.
Frequently Asked Questions
Is it safe to use ad-blocking extensions?
Yes. Ad-blocking extensions like uBlock Origin and Adblock Plus are safe and widely used. They do not install malware or slow down your browser noticeably. Some websites may ask you to turn off your ad blocker to view their content — you can choose to do that or move to a different website.
Can I block pop-ups on just one website?
Yes. In most browsers, if a website is blocked from showing pop-ups, you can click the pop-up blocker icon in your address bar and select "Always allow pop-ups on this site". You can also change this setting later by going back to your browser settings and adding or removing the website from the exceptions list.
Why do some pop-ups appear even though my blocker is on?
Some websites use code that looks like a pop-up but is technically not one, so the blocker does not catch it. Others have found ways to work around blockers. If a website is full of these, the easiest solution is to use a browser extension like uBlock Origin, which catches more types of ads than the basic blocker.
What if I accidentally clicked a fake security warning?
Clicking the pop-up itself usually does not cause harm — it is downloading or installing something from it that causes problems. If you clicked but did not read anything, you are fine. If you downloaded something, delete the file and run a scan with your actual antivirus software. If you entered information, change your password for that service.
Do I need antivirus software if I have a pop-up blocker?
A pop-up blocker and antivirus software do different things. A pop-up blocker stops ads from appearing. Antivirus software protects against malware and viruses. You should have both — most computers come with basic antivirus built in, and your browser's pop-up blocker handles most ads.