Can You Block Ads Served From the Same Domain? My Thoughts

I recently encountered a post from someone struggling to block ads within the Pinterest app and website on their iPhone. They were using AdGuard DNS and AdBlock Plus for Safari, but the ads persisted, and they suspected the ads were being served directly from Pinterest’s domain. This got me thinking about the challenges of blocking what are often called "first-party" ads and the strategies we can employ to tackle them on mobile devices.

Let’s dive into the complexities of this issue and explore potential solutions.

The Challenge of First-Party Ads

Traditional ad blockers rely on blocklists of known ad servers and domains. When an ad is served from a third-party domain (e.g., adserver.com), the ad blocker can easily identify and block the request. However, when ads are served from the same domain as the content you're trying to view (e.g., pinterest.com), it becomes much more difficult.

Here's why:

• Same Origin Policy: Browsers enforce the same-origin policy, which restricts scripts from one origin (domain, protocol, and port) from accessing resources from a different origin. In the case of first-party ads, the ads and the content share the same origin, so the browser allows them to interact freely.
• Legitimate Content: Blocking the entire domain would block legitimate content as well as ads, rendering the app or website unusable. We can't just block pinterest.com!
• Evolving Techniques: Websites and apps are constantly evolving their ad serving techniques to circumvent ad blockers. They might use sophisticated methods to disguise ads as regular content, making them harder to detect.

Why DNS-Based Blocking Often Falls Short

DNS-based ad blocking, like AdGuard DNS, works by preventing your device from resolving the domain names of known ad servers. When your device tries to access adserver.com, the DNS server returns a null IP address, effectively blocking the connection. However, if the ad is served from pinterest.com, DNS blocking won't help because you need pinterest.com to resolve in order to access the site's content.

Potential Strategies for Blocking First-Party Ads

While blocking first-party ads is challenging, it's not impossible. Here are some strategies you can try:

1. Content Blocking Extensions with Custom Filters

Content blocking extensions, like AdBlock Plus or uBlock Origin, offer more granular control than DNS-based blocking. They allow you to create custom filters that target specific elements on a webpage based on their CSS selectors, attributes, or content. This approach can be effective for blocking ads that have predictable patterns or characteristics.

How to implement:

• Inspect the Page: Use your browser's developer tools (usually accessible by pressing F12) to inspect the HTML code of the Pinterest page and identify the elements that contain the ads.

• Identify Patterns: Look for common CSS classes, IDs, or attributes that distinguish the ads from the regular content. For example, ads might be wrapped in <div> elements with a class of sponsored, ad, or advertisement.

• Create Custom Filters: Create custom filters in your content blocking extension to hide or block these elements. For example, you could use the following filter to hide elements with the class sponsored:

  pinterest.com##div.sponsored
  

  This filter tells the extension to hide all <div> elements with the class sponsored on the pinterest.com domain.

• Update Regularly: Websites often change their code, so you might need to update your filters periodically to keep them effective.

Limitations:

• Browser-Specific: Content blocking extensions only work within the browser where they're installed. They won't block ads in the Pinterest app.
• Maintenance: Maintaining custom filters can be time-consuming, as you need to monitor the website for changes and update your filters accordingly.
• Potential for Breakage: Aggressive filtering can sometimes break the functionality of the website, so you need to be careful when creating your filters.

2. Host File Modification (Advanced)

On Android, it's possible to modify the system's host file, which maps domain names to IP addresses. By adding entries to the host file that redirect ad-serving domains to a null IP address (e.g., 0.0.0.0), you can block ads system-wide. While iOS doesn't allow direct host file modification without jailbreaking, this is an option for Android users.

How to implement:

• Root Access: Modifying the host file requires root access to your Android device.

• Edit the Host File: Use a text editor with root privileges to open the /system/etc/hosts file.

• Add Redirects: Add entries to the host file that redirect ad-serving domains to 0.0.0.0. For example:

  0.0.0.0 adserver.pinterest.com
  

  This will prevent your device from resolving the adserver.pinterest.com domain.

• Save and Reboot: Save the changes to the host file and reboot your device for the changes to take effect.

Limitations:

• Root Required: Rooting your Android device can void your warranty and expose it to security risks.
• Maintenance: You need to update the host file manually as new ad-serving domains are discovered.
• Complexity: This method is more technical and requires a good understanding of Android system administration.

3. Local VPN-Based Ad Blockers

Local VPN-based ad blockers, like Blokada or AdGuard for Android, create a local VPN on your device and filter network traffic through it. This allows them to block ads system-wide, including those served from the same domain. These apps often use sophisticated techniques to identify and block ads, such as URL filtering, content inspection, and heuristic analysis.

How to implement:

• Install the App: Download and install a local VPN-based ad blocker from the Google Play Store or F-Droid.
• Configure the App: Configure the app to block ads and enable any additional features you want, such as malware protection or tracking prevention.
• Activate the VPN: Activate the VPN connection within the app. This will route all network traffic through the app, allowing it to filter out ads.

Advantages:

• System-Wide Blocking: Local VPN-based ad blockers can block ads in all apps and browsers on your device.
• Ease of Use: These apps are generally easy to set up and use, with a user-friendly interface.
• Advanced Features: Many local VPN-based ad blockers offer advanced features, such as custom filter lists, whitelisting, and logging.

Disadvantages:

• Battery Usage: Running a local VPN can consume more battery power than DNS-based blocking.
• Privacy Concerns: Some users may have privacy concerns about routing all their network traffic through a third-party app. It's important to choose a reputable and trustworthy app.

4. Private DNS with Blocklists

For Android 9 and above, you can use the Private DNS feature to specify a custom DNS server for all network traffic. While standard DNS services like Cloudflare or Google DNS don't block ads by default, you can use a DNS service that incorporates blocklists specifically designed to filter out advertising and tracking domains.

How to implement:

• Navigate to Settings: Go to Settings > Network & Internet > Private DNS.
• Select "Private DNS provider hostname".
• Enter a DNS Provider: Enter the hostname of a DNS provider that offers ad blocking. Some popular options include AdGuard DNS (dns.adguard.com) or NextDNS (you'll need a NextDNS account and to find your personalized DNS address).

Advantages:

• System-Wide Blocking: Blocks ads across all apps and browsers.
• Relatively Easy Setup: Easier than some other methods, especially on Android.
• Improved Privacy: Encrypts your DNS queries, preventing your ISP from snooping on your browsing activity.

Disadvantages:

• Limited Customization: You are limited to the blocklists used by the DNS provider.
• Potential for False Positives: Blocklists can sometimes block legitimate content.
• Effectiveness Varies: The effectiveness of DNS-based ad blocking can vary depending on the sophistication of the ad serving techniques used by websites and apps.

5. Browser-Specific Solutions

If you primarily use Pinterest in a web browser, you can consider using a browser with built-in ad blocking or installing ad blocking extensions.

• Brave Browser: Brave Browser has built-in ad blocking and tracking protection. It blocks ads and trackers by default, without requiring any additional configuration.
• Firefox with uBlock Origin: Firefox is a highly customizable browser that supports extensions. uBlock Origin is a powerful and efficient ad blocking extension that can block a wide range of ads and trackers.

Advantages:

• Effective Ad Blocking: These solutions can effectively block ads in the browser.
• Customization: uBlock Origin offers a high degree of customization, allowing you to create custom filters and manage whitelists.
• Privacy Protection: These solutions can also protect your privacy by blocking tracking scripts and cookies.

Disadvantages:

• Browser-Specific: These solutions only work within the browser where they're installed. They won't block ads in the Pinterest app.

6. Using a Dedicated Pinterest Ad Blocker (If Available)

While I'm not aware of any specific ad blockers designed exclusively for Pinterest, it's worth checking the app stores for such solutions. These apps might use specialized techniques to block ads within the Pinterest app, such as content filtering or API manipulation.

Limitations:

• Availability: Dedicated Pinterest ad blockers might not be available for your platform or region.
• Trustworthiness: It's important to choose a reputable and trustworthy app to avoid security risks.
• Effectiveness: The effectiveness of these apps can vary depending on the ad serving techniques used by Pinterest.

Addressing the Original Poster's Situation

Given the original poster's setup (iPhone with AdGuard DNS and AdBlock Plus for Safari), here's what I'd suggest:

1. Focus on Safari: Since they're using AdBlock Plus, concentrate on optimizing its settings and custom filters for the Pinterest website.
2. Inspect Pinterest's Code: Use Safari's developer tools to identify the specific elements serving ads and create targeted filters.
3. Consider a Local VPN: If ads persist within the Pinterest app, exploring a local VPN-based ad blocker like AdGuard Pro might be the next step.

My Recommendations

• For most users: Start with a combination of Private DNS with a reliable ad-blocking list (like AdGuard DNS) and a content blocker in your browser with custom filters. This provides a good balance of system-wide protection and granular control.
• For advanced users: If you're comfortable with technical configurations, consider rooting your Android device and modifying the host file for maximum control over ad blocking.
• For privacy-conscious users: Combine a local VPN-based ad blocker with a privacy-focused browser like Brave for comprehensive protection against ads and trackers.

What About Paid Solutions?

While many free ad blocking solutions are available, paid solutions often offer additional features and benefits, such as:

• More Advanced Blocking Techniques: Paid solutions may use more sophisticated techniques to identify and block ads, such as content inspection and heuristic analysis.
• Customizable Filter Lists: Paid solutions may allow you to customize your filter lists and add your own custom filters.
• Priority Support: Paid solutions typically offer priority support, so you can get help quickly if you encounter any problems.
• Regular Updates: Paid solutions are typically updated more frequently than free solutions, ensuring that they remain effective against the latest ad serving techniques.

Whether or not to pay for an ad blocking solution depends on your individual needs and preferences. If you're a heavy internet user who values privacy and ad-free browsing, a paid solution may be worth the investment. However, if you're a casual user, a free solution may be sufficient.

Final Thoughts

Blocking first-party ads is an ongoing challenge, as websites and apps are constantly evolving their ad serving techniques. However, by using a combination of strategies and staying informed about the latest ad blocking techniques, you can significantly reduce the number of ads you see on your mobile devices.

Remember that the best approach is often a layered one, combining DNS-based blocking with browser extensions and, if necessary, a local VPN. Experiment with different solutions to find what works best for you and your specific needs.