Stop Websites From Mining Crypto on Your PC

This guide shows you how to stop websites from using your computer’s processing power to mine cryptocurrencies without your consent. By following these steps, you’ll block in-browser miners, reduce CPU strain, and keep your system running smoothly. You’ll need a modern web browser and a few minutes to adjust settings.

What You’ll Need

A computer with an internet connection
Access to your browser’s settings or extensions store
Optional: a reputable ad-blocker or anti-mining extension (free options available)

Step-by-Step

Update your browser. Ensure you’re using the latest version of Chrome, Firefox, Edge, or Safari. Recent updates often include built-in protections against cryptojacking scripts.
Enable your browser’s built-in protections.
- Chrome/Edge: Go to Settings → Privacy and Security → Security. Turn on “Use secure DNS” and ensure “Safe Browsing” is set to “Enhanced protection” (Chrome) or “Strict” (Edge).
- Firefox: Go to Settings → Privacy & Security. Under “Enhanced Tracking Protection,” choose “Strict.” This blocks known cryptominers.
- Safari: Go to Preferences → Privacy. Check “Prevent cross-site tracking” and “Hide IP address.” While not specific to mining, these reduce tracking scripts.
Install a dedicated anti-mining extension. Search your browser’s official extension store for “No Coin” or “MinerBlock.” These extensions block known mining domains and scripts. Install one and keep it enabled.
Use a reputable ad-blocker. Many cryptominers are delivered through malicious ads. Install an ad-blocker like uBlock Origin (free, open-source). It has a built-in filter against mining scripts.
Disable JavaScript on untrusted sites. For sites you don’t fully trust, you can disable JavaScript entirely. In Chrome/Edge, click the padlock icon in the address bar → Site settings → JavaScript → Block. In Firefox, click the shield icon → Disable protection for this site (temporarily) or use an extension like NoScript to selectively allow scripts.
Keep your operating system and antivirus updated. Windows Defender and other modern antivirus programs now detect and block cryptojacking malware. Ensure real-time protection is on.
Monitor your CPU usage. If you suspect a site is mining, open Task Manager (Windows: Ctrl+Shift+Esc) or Activity Monitor (Mac: Spotlight → Activity Monitor). Look for high CPU usage when a tab is open. If one tab spikes your CPU, close it immediately.
Consider a hosts file block. Advanced users can add known mining domains to the hosts file to block them system-wide. This is more technical and not necessary for most users.

Common Mistakes

Only using one layer of protection. Relying solely on an ad-blocker may miss some miners. Combine built-in protections, an anti-mining extension, and common sense.
Ignoring browser updates. Outdated browsers lack the latest security patches and mining protections.
Installing untrusted extensions. Some “anti-mining” extensions themselves contain malware. Always download from official stores and check reviews.
Disabling JavaScript on trusted sites. Blocking JS on sites you use regularly can break functionality. Use selective blocking instead.
Assuming all high CPU usage is mining. Some websites (like video players or complex apps) legitimately use high CPU. Check multiple tabs before assuming mining.

Tips

Use a browser with built-in cryptojacking protection, like Opera or Brave, if you want extra security without extensions.
Regularly clear your browser cache and cookies to remove any malicious scripts that may have been stored.
Be cautious with websites that offer free downloads or streaming; they are more likely to run miners.
If you’re a developer, consider using a content security policy (CSP) on your own sites to prevent unauthorized scripts.
For mobile devices, the same principles apply—use a mobile browser with tracking protection.

Troubleshooting

If you still notice high CPU usage or suspect mining:

Check your extensions. Disable all extensions and re-enable them one by one to identify any that might be malicious or conflicting.
Run a full antivirus scan. Some miners are installed as malware, not just in-browser. A thorough scan can detect and remove them.
Reset your browser settings. In Chrome/Edge, go to Settings → Reset settings → Restore settings to their original defaults. This removes malicious extensions and restores default protections.
Try a different browser. If the issue persists, test another browser to see if it’s browser-specific.
Check your router. In rare cases, a compromised router can inject mining scripts into web pages. Update your router’s firmware and change its admin password.
Use a network-level blocker. Tools like Pi-hole can block mining domains across all devices on your home network.

Frequently Asked Questions

Is in-browser mining illegal?

Mining without your consent is generally considered malicious. Many jurisdictions treat it as unauthorized use of computing resources, but legality varies. The best approach is to block it regardless.

Can mining damage my PC?

Yes, prolonged mining can overheat your CPU/GPU, reduce its lifespan, and increase electricity bills. It also slows down your system.

Are all cryptocurrencies mined in browsers?

No, most cryptocurrencies require specialized hardware. In-browser mining typically targets coins like Monero, which are designed to be CPU-friendly.

Will blocking mining affect my browsing experience?

No, blocking mining scripts should not affect legitimate website functionality. Some sites may ask you to disable your ad-blocker, but that’s separate from mining protection.

Do I need to pay for anti-mining software?

No, effective free options like uBlock Origin and No Coin are available. Paid antivirus suites also include protection, but free tools are sufficient for most users.

Can I mine cryptocurrency intentionally?

Yes, you can mine legally on sites that ask for your consent. However, it’s rarely profitable due to high electricity costs and low coin values. If you choose to do so, only use reputable services.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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