> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/mullvad/mullvadvpn-app/llms.txt
> Use this file to discover all available pages before exploring further.

# Content Blockers

> Block ads, trackers, malware, adult content, gambling, and social media at the DNS level

## Overview

Content blockers use **DNS-based filtering** to block unwanted content before it reaches your device. When enabled, Mullvad's DNS resolver returns a non-routable address for blocked domains, preventing your device from connecting to them.

Available blockers:

* **Ads**: Advertising networks and services
* **Trackers**: Analytics and tracking domains
* **Malware**: Known malicious domains
* **Adult Content**: Adult and NSFW websites
* **Gambling**: Betting and gambling sites
* **Social Media**: Social networking platforms

<Note>
  Content blockers are available on all platforms: Windows, Linux, macOS, Android, and iOS.
</Note>

## How DNS-Based Blocking Works

### Normal DNS Resolution

```
Browser: "What's the IP of ad-network.com?"
   │
   ▼
DNS Resolver: "It's 192.0.2.1"
   │
   ▼
Browser: [Connects to 192.0.2.1 and loads ads]
```

### With Content Blocker Enabled

```
Browser: "What's the IP of ad-network.com?"
   │
   ▼
DNS Resolver: "Domain blocked - 0.0.0.0"
   │
   ▼
Browser: [Cannot connect - no ads loaded]
```

The DNS resolver returns:

* `0.0.0.0` (non-routable address), OR
* `NXDOMAIN` (domain does not exist)

This prevents the connection from being established.

## Available Content Blockers

### Ads

**Blocks**: Advertising networks, banner ads, video ads, pop-ups

**Examples**:

* `doubleclick.net`
* `googlesyndication.com`
* `advertising.com`
* Ad servers and networks

**Use cases**:

* Cleaner browsing experience
* Faster page loading
* Reduced bandwidth usage
* Privacy improvement (ads track you)

### Trackers

**Blocks**: Analytics services, tracking pixels, user profiling

**Examples**:

* `google-analytics.com`
* `facebook.com` tracking pixels
* `hotjar.com`
* Analytics and heat mapping services

**Use cases**:

* Enhanced privacy
* Prevent behavioral tracking
* Reduce data collection
* Limit cross-site tracking

### Malware

**Blocks**: Known malicious domains, phishing sites, malware distribution

**Examples**:

* Phishing websites
* Malware download sites
* Command & control servers
* Compromised domains

**Use cases**:

* Security protection
* Phishing prevention
* Malware blocking
* Safe browsing

<Info>
  The malware blocker uses threat intelligence feeds that are regularly updated to block newly discovered malicious domains.
</Info>

### Adult Content

**Blocks**: Adult websites, NSFW content, pornography

**Use cases**:

* Parental controls
* Family safety
* Workplace compliance
* Personal accountability

### Gambling

**Blocks**: Online gambling, betting sites, casinos

**Examples**:

* Online casinos
* Sports betting sites
* Poker platforms
* Lottery websites

**Use cases**:

* Responsible gambling support
* Financial protection
* Workplace productivity
* Self-imposed restrictions

### Social Media

**Blocks**: Social networking platforms

**Examples**:

* Facebook/Meta properties
* Twitter/X
* Instagram
* TikTok
* LinkedIn
* Reddit

**Use cases**:

* Digital wellness
* Productivity improvement
* Reduce screen time
* Focus enhancement

<Warning>
  Blocking social media may affect authentication ("Sign in with Facebook") and social sharing features on other websites.
</Warning>

## Enabling Content Blockers

### Using the GUI

<Steps>
  <Step title="Open DNS Settings">
    Navigate to **Settings** → **VPN settings** → **DNS settings**
  </Step>

  <Step title="Ensure Default DNS">
    Make sure **Use default DNS** is selected (not custom DNS)
  </Step>

  <Step title="Enable Desired Blockers">
    Toggle on the blockers you want:

    **Privacy & Security** (recommended for everyone):

    * ☑ **Block ads**
    * ☑ **Block trackers**
    * ☑ **Block malware**

    **Additional Filters** (optional):

    * ☐ **Block adult content**
    * ☐ **Block gambling**
    * ☐ **Block social media**
  </Step>

  <Step title="Changes Apply Immediately">
    No reconnection required - blockers activate instantly
  </Step>
</Steps>

### Using the CLI

<Tabs>
  <Tab title="Privacy & Security">
    Enable ads, trackers, and malware blocking:

    ```bash theme={null}
    mullvad dns set default \
      --block-ads \
      --block-trackers \
      --block-malware
    ```
  </Tab>

  <Tab title="All Blockers">
    Enable all available content blockers:

    ```bash theme={null}
    mullvad dns set default \
      --block-ads \
      --block-trackers \
      --block-malware \
      --block-adult-content \
      --block-gambling \
      --block-social-media
    ```
  </Tab>

  <Tab title="Specific Blockers">
    Enable only specific blockers:

    ```bash theme={null}
    # Only malware blocking
    mullvad dns set default --block-malware

    # Malware + adult content
    mullvad dns set default \
      --block-malware \
      --block-adult-content
    ```
  </Tab>

  <Tab title="Disable All">
    Return to unfiltered DNS:

    ```bash theme={null}
    mullvad dns set default
    ```
  </Tab>
</Tabs>

### Check Current Settings

```bash theme={null}
mullvad dns get
```

Output:

```
Custom DNS: no
Block ads: true
Block trackers: true
Block malware: true
Block adult content: false
Block gambling: false
Block social media: false
```

## What Content Blockers Can and Cannot Do

### ✅ What DNS Blocking CAN Do

* **Block entire domains**: Prevent connections to blocked domains
* **Prevent tracking pixels**: Block analytics and tracking scripts
* **Stop malware downloads**: Block known malicious domains
* **Filter ads**: Remove ads from most websites and apps
* **System-wide blocking**: Works for all apps (not just browsers)
* **No software installation**: Built into Mullvad's DNS

### ❌ What DNS Blocking CANNOT Do

* **Block specific URLs**: Cannot block `example.com/ads` while allowing `example.com`
* **Block first-party ads**: Cannot block ads served from the same domain (e.g., YouTube ads from `youtube.com`)
* **Block inline content**: Cannot remove ads already embedded in HTML
* **Granular control**: Cannot block specific elements on a page
* **Bypass HTTPS inspection**: Cannot see encrypted HTTPS content
* **Cosmetic filtering**: Cannot hide blocked ad spaces (browser ad blockers do this)

<Info>
  **DNS blocking vs. Browser ad blockers:**

  * DNS blocking: Prevents connections to entire domains
  * Browser ad blockers (uBlock Origin, AdBlock Plus): Removes specific elements, hides ad spaces, more granular control

  For maximum ad blocking, use **both** together.
</Info>

## How Blocking Affects Different Services

### Web Browsing

**Ads & Trackers**:

* ✅ Most ads removed
* ✅ Tracking scripts blocked
* ❌ First-party ads still show (e.g., Amazon product ads)
* ❌ Empty spaces where ads were (use browser ad blocker to hide)

**Malware**:

* ✅ Phishing sites blocked
* ✅ Malware distribution prevented
* ✅ Protection against drive-by downloads

### Mobile Apps

**Ads in apps**:

* ✅ Most in-app ads blocked
* ✅ Works for all apps, not just browsers
* ❌ Some apps may malfunction without ads
* ❌ Apps that require ad networks may show errors

### Social Media Blocking

**Blocked**:

* Cannot access social media websites
* Apps cannot connect
* Embedded social widgets fail

**Side effects**:

* "Sign in with Facebook" won't work
* Social sharing buttons disabled
* Comments sections using social logins unavailable

## Combining Blockers

### Recommended Combinations

<Tabs>
  <Tab title="Privacy-Focused">
    Block ads, trackers, and malware:

    ```bash theme={null}
    mullvad dns set default \
      --block-ads \
      --block-trackers \
      --block-malware
    ```

    **Benefits**: Enhanced privacy, security, faster browsing
    **Trade-offs**: Some sites may detect ad blocking
  </Tab>

  <Tab title="Family-Safe">
    Privacy blockers + adult content + gambling:

    ```bash theme={null}
    mullvad dns set default \
      --block-ads \
      --block-trackers \
      --block-malware \
      --block-adult-content \
      --block-gambling
    ```

    **Benefits**: Child-friendly environment
    **Trade-offs**: May block legitimate content
  </Tab>

  <Tab title="Productivity-Focused">
    Malware + social media:

    ```bash theme={null}
    mullvad dns set default \
      --block-malware \
      --block-social-media
    ```

    **Benefits**: Eliminate social media distractions
    **Trade-offs**: Cannot access social networks even when needed
  </Tab>

  <Tab title="Security-Only">
    Only malware blocking:

    ```bash theme={null}
    mullvad dns set default --block-malware
    ```

    **Benefits**: Protection without affecting browsing
    **Trade-offs**: Ads and tracking remain
  </Tab>
</Tabs>

## Compatibility

Content blockers work with:

* ✅ [WireGuard protocol](/features/wireguard)
* ✅ [Quantum-resistant tunnels](/features/quantum-resistant)
* ✅ [Multihop](/features/multihop)
* ✅ [DAITA](/features/daita)
* ✅ [Obfuscation protocols](/features/obfuscation)
* ✅ [Custom DNS](/features/custom-dns)\* (see note below)
* ✅ [Split tunneling](/features/split-tunneling)
* ✅ [Local network access](/features/local-network-access)

<Warning>
  **Content blockers require Mullvad's default DNS**. If you enable custom DNS, content blockers are automatically disabled because your custom DNS provider handles DNS resolution.
</Warning>

## Performance Impact

Content blocking has minimal performance overhead:

### Benefits

* **Faster page loading**: No time spent loading ads
* **Reduced bandwidth**: Less data transferred
* **Lower CPU usage**: Fewer scripts to execute
* **Better battery life**: Especially on mobile devices

### Overhead

* **DNS lookup**: Negligible (\<1ms additional processing)
* **Blocklist updates**: Automatic, transparent
* **Memory usage**: Minimal (blocklists on DNS server)

<Info>
  In practice, content blocking **improves** performance by preventing unnecessary connections and downloads.
</Info>

## Troubleshooting

### Website or Service Not Working

If a website malfunctions with blockers enabled:

1. **Identify the issue**: Check browser console for blocked requests

2. **Test by disabling blockers**:
   ```bash theme={null}
   # Disable all blockers temporarily
   mullvad dns set default

   # Test if site works
   # Then re-enable blockers
   mullvad dns set default --block-ads --block-trackers --block-malware
   ```

3. **Disable specific blocker**:
   ```bash theme={null}
   # Example: Disable ad blocking but keep others
   mullvad dns set default --block-trackers --block-malware
   ```

4. **Use browser exceptions**: Some browser ad blockers allow site-specific whitelisting

### Ads Still Appearing

If you still see ads:

1. **Clear DNS cache** (see below)

2. **Check blocker status**:
   ```bash theme={null}
   mullvad dns get
   ```

3. **Verify default DNS is active**: Ensure not using custom DNS

4. **First-party ads**: These cannot be blocked by DNS (use browser ad blocker)

5. **Test blocking**:
   ```bash theme={null}
   # Should return 0.0.0.0 or NXDOMAIN
   nslookup doubleclick.net
   nslookup ads.google.com
   ```

### Clearing DNS Cache

After changing blockers, clear your DNS cache:

<Tabs>
  <Tab title="Windows">
    ```bash theme={null}
    ipconfig /flushdns
    ```
  </Tab>

  <Tab title="macOS">
    ```bash theme={null}
    sudo dscacheutil -flushcache
    sudo killall -HUP mDNSResponder
    ```
  </Tab>

  <Tab title="Linux">
    ```bash theme={null}
    # systemd-resolved
    sudo systemd-resolve --flush-caches

    # dnsmasq
    sudo killall -HUP dnsmasq

    # nscd
    sudo systemctl restart nscd
    ```
  </Tab>

  <Tab title="Android">
    Settings → Apps → Show system → Private DNS → Clear cache

    Or restart device.
  </Tab>

  <Tab title="iOS">
    Settings → General → Reset → Reset Network Settings

    (Note: This resets all network settings)
  </Tab>
</Tabs>

Also clear **browser cache**:

* Chrome: Settings → Privacy and security → Clear browsing data
* Firefox: Settings → Privacy & Security → Clear Data
* Safari: Preferences → Privacy → Manage Website Data → Remove All

### Social Media Login Issues

If social login ("Sign in with Facebook") fails:

1. **Temporarily disable social media blocker**:
   ```bash theme={null}
   # Keep other blockers active
   mullvad dns set default --block-ads --block-trackers --block-malware
   ```

2. **Complete login**

3. **Re-enable social media blocker** (if desired):
   ```bash theme={null}
   mullvad dns set default \
     --block-ads \
     --block-trackers \
     --block-malware \
     --block-social-media
   ```

### Legitimate Sites Blocked

If a legitimate website is blocked:

1. **False positive**: Blocklists occasionally block legitimate domains

2. **Disable blocker temporarily**:
   ```bash theme={null}
   # Disable specific blocker
   mullvad dns set default --block-trackers --block-malware
   # (removed --block-ads in this example)
   ```

3. **Report false positive**: Contact Mullvad support with domain details

4. **Use custom DNS**: Switch to unfiltered DNS if needed
   ```bash theme={null}
   mullvad dns set custom 1.1.1.1
   ```

## Comparison with Other Solutions

### DNS-Based Blocking (Mullvad Content Blockers)

**Pros**:

* System-wide (all apps)
* No additional software
* Blocks tracking in all apps
* Low resource usage
* Works on mobile

**Cons**:

* Cannot block first-party ads
* No cosmetic filtering
* All-or-nothing per domain

### Browser Extensions (uBlock Origin, AdBlock Plus)

**Pros**:

* Granular URL/element blocking
* Cosmetic filtering (hides ad spaces)
* Can block first-party ads
* Per-site whitelisting

**Cons**:

* Browser-only (doesn't block app ads)
* Resource usage in browser
* Must install in each browser
* Not available on mobile browsers (limited)

### Network-Wide Blockers (Pi-hole, AdGuard Home)

**Pros**:

* Blocks for all devices on network
* Customizable blocklists
* Detailed statistics
* Full control

**Cons**:

* Requires separate device/server
* Network configuration needed
* Maintenance required

<Info>
  **Best approach**: Combine multiple layers:

  1. Mullvad content blockers (system-wide, easy)
  2. Browser ad blocker (granular control)
  3. (Optional) Network-wide blocker (protect all devices)
</Info>

## Privacy Considerations

### What Mullvad Sees

With content blockers enabled:

* **Mullvad sees**: DNS queries (e.g., "user queried doubleclick.net")
* **Mullvad does NOT log**: DNS queries are not stored
* **Blocklist matching**: Happens on DNS server (not logged)
* **No personal data**: DNS queries are not associated with accounts

<Note>
  Mullvad's no-logs policy applies to DNS queries. Content blocker usage does not compromise privacy.
</Note>

### Custom DNS vs. Mullvad DNS with Blockers

If you use custom DNS:

* Content blockers unavailable (custom DNS provider handles resolution)
* Privacy depends on custom DNS provider's policy
* May have own blocking features (e.g., Cloudflare for Families)

With Mullvad DNS + blockers:

* Mullvad's no-logs policy
* Integrated blocking
* No third-party DNS provider

## Best Practices

### Recommended Configuration

For most users:

```bash theme={null}
mullvad dns set default \
  --block-ads \
  --block-trackers \
  --block-malware
```

**Why**:

* Ads and trackers violate privacy
* Malware blocking enhances security
* Minimal disruption to legitimate services

### Advanced Configuration

For maximum filtering:

```bash theme={null}
mullvad dns set default \
  --block-ads \
  --block-trackers \
  --block-malware \
  --block-adult-content \
  --block-gambling \
  --block-social-media
```

**Consider**:

* May break some website features
* Social logins won't work
* Test critical services first

### Testing Strategy

1. **Start with minimal blocking**: Only malware
2. **Add ads and trackers**: Evaluate browsing experience
3. **Add optional blockers**: If needed for specific use cases
4. **Document issues**: Note which sites require unblocking
5. **Adjust as needed**: Find balance between blocking and functionality

## Related Features

* [Custom DNS](/features/custom-dns) - Configure DNS settings and blockers
* [Split Tunneling](/features/split-tunneling) - DNS behavior with excluded apps
* [WireGuard Protocol](/features/wireguard) - Base VPN protocol
* [Local Network Access](/features/local-network-access) - LAN connectivity settings

## Technical Details

### Implementation

From source code (mullvad-types/src/settings/dns.rs:22-31):

```rust theme={null}
pub struct DefaultDnsOptions {
    pub block_ads: bool,
    pub block_trackers: bool,
    pub block_malware: bool,
    pub block_adult_content: bool,
    pub block_gambling: bool,
    pub block_social_media: bool,
}
```

Blockers are boolean flags sent to Mullvad DNS servers, which apply filtering based on enabled options.

### Blocklist Updates

* **Automatic**: Mullvad updates blocklists server-side
* **No client action**: Devices automatically get updated blocking
* **Frequency**: Regular updates (daily/weekly)
* **Sources**: Reputable threat intelligence and filter lists

## Further Reading

* [Mullvad DNS Documentation](https://mullvad.net/en/help/dns-leaks/)
* [DNS-Based Content Filtering](https://en.wikipedia.org/wiki/DNS_blocking)
* [Browser Privacy Tools](https://mullvad.net/en/help/tag/privacy/)