How do I stop websites from mining crypto in my browser?

You can stop most websites from mining crypto in your browser by closing the offending tab, blocking its scripts, and removing any suspicious browser extensions. For ongoing protection, keep your browser updated and use a trusted blocker that specifically blocks cryptocurrency mining.

Stop the activity right away

If your computer suddenly gets hot, its fans get loud, or browsing slows down, close the website you suspect. Browser mining uses your CPU—your computer’s main processor—to do calculations, which can cause those symptoms.

If you cannot tell which tab is responsible:

• Open your browser’s built-in task manager, if it has one. In Chrome and Edge, you can usually open it with Shift + Esc.
• Look for a tab or extension using a lot of CPU.
• End that task or close the tab.

High CPU use is a clue, not proof of mining. Video calls, games, and poorly built websites can also use plenty of processing power.

If the activity continues, quit the browser completely. Some browsers keep background apps running after you close their windows. Check Windows Task Manager or macOS Activity Monitor to see whether browser processes remain, and end them if necessary. This may lose unsaved work.

Block mining before it starts

Start with your browser’s privacy and security settings. Turn on protection against cryptominers if that option is available. Cryptojacking means using your device to mine cryptocurrency without your informed permission.

A reputable content blocker can add protection by blocking known mining scripts—the small programs websites run in your browser. Choose one that:

• Comes from your browser’s official extension store.
• Has an established developer and a clear privacy policy.
• Maintains updated filtering rules, including protection against miners.

An official-store listing alone does not guarantee safety. Avoid installing several unfamiliar “anti-mining” extensions; a malicious extension can create the very problem you are trying to solve.

Keep both your browser and blocker updated. No blocklist catches every new or disguised mining script.

Restrict the problem website

If you need to visit a site that appears to mine, block JavaScript for that site where your browser supports it. JavaScript is the programming language used for many interactive website features—and to start most browser miners.

Blocking it can prevent mining, but it may also break menus, logins, or videos. If the site will not work without running unwanted code, leave rather than weaken your protection.

You can also clear that site’s stored data and revoke unnecessary permissions through its site settings. This helps reset its access, but clearing cookies alone is not a reliable mining blocker. Mining usually does not require a permission prompt, and blocking notifications does not stop it.

Check for something beyond a website

Ordinary webpage mining generally stops when the page closes. If the problem returns on unrelated sites or continues after the browser fully exits:

• Remove unfamiliar or unnecessary extensions.
• Check your startup pages so the suspicious site does not reopen automatically.
• Run a scan with your operating system’s built-in security tool or another trusted antivirus.

Do not download a “miner remover” from a warning pop-up or pay someone claiming your browser needs an urgent cleanup. Those warnings can be scams.

The bottom line

Close the suspicious tab first, then use updated browser protections and a trusted blocker. If heavy processor use continues after you fully exit the browser, investigate extensions or unwanted software rather than assuming a website is still mining.