SideBySide ads: what it is and how to remove it

Something is sending it there. On one site only, that site's ads are the cause and leaving the site ends it.

On many different sites, the usual causes are an extension you installed with something else, a site you once allowed to send notifications, or an ad-supported program in Windows that changes how the browser behaves. sidebysidesearch.com itself is only a stop on the way: it records the visit and forwards you to whatever advertiser pays most.

Check the extensions page, then the list of sites allowed to send notifications, then Installed apps sorted by date. Removing the cause stops the redirects; blocking the domain alone usually does not, because the network moves to a new one.

Very unlikely, unless you downloaded and opened something from the pages it led to. Redirect domains such as sidebysidesearch.com sell your visit to advertisers; they do not need to install anything to make money.

What can be installed is the thing that causes the redirects in the first place, such as an extension or an ad-supported program that came with free software. That is why the checks in this guide look at extensions, notification permissions and Installed apps.

A full scan with Microsoft Defender afterwards gives you a clear answer about the rest of the PC. If the scan is clean and the redirects stop after removing the cause, you are done.

Because that is its whole purpose. SideBySide is an adware extension, and its operators are paid for every ad it displays and every click it gets. In this case the ads take the form of redirects through ad pages.

They are chosen by ad networks that accept almost any advertiser, which is why so many look like warnings or prizes. The ads are not a sign that your PC is broken or infected with something worse; they are a sign that something on it, or in the browser, has permission to advertise. Removing that permission or program stops them.

Yes, if you use more than one. We saw SideBySide in Chrome, Edge and Firefox, and each browser keeps its own extensions, notification permissions and settings. Chrome and Edge share the same extension format, so one installer can add the same adware to both, while Firefox has its own add-ons.

Check every browser on the PC, including ones you rarely open. If you sync a browser with an account, clean it while signed in, so that the removal reaches your other computers rather than the adware returning from them.

Look for redirects to sidebysidesearch.com. That is the trace SideBySide leaves, and it shows up as redirects through ad pages. Ads that appear on every site, including ones that never carried ads before, point to something on your PC or in the browser rather than to the sites themselves.

A quick test is a private window, where extensions are off by default: if the ads disappear there, an extension is responsible. If they appear even with the browser closed, the source is a notification permission or a program in Windows.

Many security products do not block adware or notification sites by default, because users often agreed to them, even through a misleading prompt. Notification spam installs nothing at all, so there is no file to detect.

In Windows 11 you can make Microsoft Defender block potentially unwanted apps: open Windows Security > App & browser control > Reputation-based protection settings and turn on Potentially unwanted app blocking. If notifications caused the pop-ups, no scanner will report them; the fix is in the browser's site settings.

Probably not. Clicking an ad usually only opens a page, and a page cannot install programs on an up-to-date Windows PC without your help.

You are at risk only if you then downloaded and ran a file, allowed notifications, entered card or login details, or called a phone number shown on the page. Delete any download and run a full and offline scan.

Change passwords you typed, from a clean device. Call your bank if you gave card details. If you called a number or allowed remote access, see the next question.

Yes. Adware runs in the background, loads ad scripts, opens extra tabs and contacts its servers, all of which use processor time, memory and bandwidth. Ad-heavy extensions also slow down every page, because they inspect and change it before you see it.

The effect is strongest on older PCs and when several adware programs arrived together. After removal, restart the PC and check Task Manager for anything still using a lot of resources that you do not recognise. Speed usually returns to normal once the ads stop.

The number belongs to scammers, not to Microsoft or an antivirus company. If you only talked, hang up and do not call back. If you let them connect to the PC, disconnect it from the internet, uninstall the remote access program they used, such as AnyDesk, TeamViewer, ScreenConnect or UltraViewer, and run a full and offline scan.

If you paid or gave bank details, call your bank at once on the number printed on your card. Change any passwords you typed while they were connected, and report the call.

Fortect scans Windows for malware and unwanted programs and repairs the system files and settings they change, and its free scan shows what it finds on your PC before you decide anything.

For SideBySide, follow the plan above as well: the browser steps take back permissions and settings that no scanner treats as a threat, and uninstalling the program that brought it removes the source.

Run Microsoft Defender's full scan and, if anything was found, its offline scan as a second opinion. If the symptoms are gone after the plan and both scans are clean, there is nothing more to do.