Rethink DNS - Complete Android Guide (2025)

Table of Contents

Overview

Rethink DNS is a free, open-source DNS resolver and firewall for Android that provides:

  • DNS-based content blocking (ads, malware, trackers)
  • Per-app firewall capabilities
  • On-device DNS server
  • Support for DNS-over-HTTPS (DoH) and DNS-over-TLS (DoT)
  • Network monitoring and logging

Official Resources:

Key Features

1. DNS Blocking

  • 190+ pre-configured blocklists
  • Custom blocklist support
  • Domain whitelisting/blacklisting

2. Firewall

  • Per-app network control
  • Block background data
  • IP-based blocking
  • Domain-based filtering

3. Privacy

  • On-device processing
  • No data collection
  • Open-source and auditable

4. Protocols Supported

  • DNS-over-HTTPS (DoH)
  • DNS-over-TLS (DoT)
  • DNSCrypt
  • DNS Proxy
  • WireGuard VPN integration

Installation & Setup

Initial Setup

  1. Install from:

    • Google Play Store
    • F-Droid
    • GitHub Releases (APK)

  2. First Launch Configuration:

    1. Open Rethink DNS
2. Grant VPN permission (required for DNS interception)
3. Choose DNS mode:
   - Rethink DNS (recommended for beginners)
   - Custom DNS
   - DNS Proxy

  3. Enable the Service:

    • Tap the power button/toggle at the top
    • Allow VPN connection request
    • Verify connection in notification bar

Essential Daily Commands & Operations

1. Start/Stop DNS & Firewall

Start Protection:

Main Screen → Power Button (Top) → Enable
  • Green indicator = Active
  • Gray indicator = Inactive

Stop Protection:

Main Screen → Power Button → Disable

Quick Toggle:

  • Use notification quick tile
  • Add to Quick Settings panel

2. Check Current Status

View Active Connections:

Home Screen → Network Activity Section

Shows:

  • Active queries
  • Blocked domains
  • Apps making connections

View Statistics:

Home Screen → Scroll to Stats

Displays:

  • Total queries
  • Blocked queries
  • Allowed queries
  • Top blocked domains

3. Block/Unblock Specific Apps

Block an App from Internet:

Configure → Apps → Select App → Toggle OFF

Block App’s Background Data Only:

Configure → Apps → Select App → 3-dot menu → Block when screen off

Allow App Through Firewall:

Configure → Apps → Select App → Toggle ON

Example: Block Facebook’s Background Data

1. Configure → Apps
2. Search/Find "Facebook"
3. Tap Facebook → Options menu (⋮)
4. Select "Block when screen off"
5. Result: Facebook works when app is open, blocked when closed

4. DNS Configuration

Switch DNS Provider:

Configure → DNS → Select Provider

Popular DNS Options:

  • Rethink DNS (Default with blocklists)
  • Cloudflare (1.1.1.1) - Fast & privacy-focused
  • Quad9 - Security & malware blocking
  • Google DNS (8.8.8.8) - Fast but less privacy
  • AdGuard DNS - Ad blocking

Configure Custom DNS:

Configure → DNS → Add Custom DNS
Enter:
- Name: "My Custom DNS"
- URL: https://dns.example.com/dns-query (DoH)
  OR
- IP: 1.1.1.1 (Plain DNS)
- Port: 853 (for DoT)

Example: Setup Cloudflare DoH

1. Configure → DNS
2. Tap "+" (Add)
3. Name: Cloudflare DoH
4. URL: https://cloudflare-dns.com/dns-query
5. Protocol: DNS-over-HTTPS
6. Save
7. Select as active DNS

5. Configure Blocklists

Enable Pre-configured Blocklists:

Configure → DNS → Configure Blocklists

Popular Blocklist Combinations:

Light Blocking (Recommended for Daily Use):

✓ 1Hosts (Lite)
✓ AdGuard DNS Filter
✓ OISD Basic

Medium Blocking:

✓ 1Hosts (Pro)
✓ Hagezi Pro
✓ StevenBlack Unified
✓ OISD Full

Aggressive Blocking:

✓ Hagezi Ultimate
✓ 1Hosts (Xtra)
✓ Energized Ultimate
✓ All Ads & Trackers lists

Apply Changes:

Select desired lists → Tap "Apply" (bottom) → Wait for download

6. Whitelist/Blacklist Domains

Whitelist a Domain (Allow Permanently):

Configure → DNS → Domain Rules → Whitelist
Tap "+" → Enter domain → Save

Example: Whitelist cdn.example.com

1. Configure → DNS → Domain Rules
2. Tap "Whitelist" tab
3. Tap "+" button
4. Enter: cdn.example.com
5. Save
6. Domain will always be allowed, even if in blocklists

Blacklist a Domain (Block Permanently):

Configure → DNS → Domain Rules → Blacklist
Tap "+" → Enter domain → Save

Example: Block tracker.analytics.com

1. Configure → DNS → Domain Rules
2. Tap "Blacklist" tab
3. Tap "+"
4. Enter: tracker.analytics.com
5. Save

7. Monitor Network Activity

View Real-time Queries:

Home Screen → Network Activity (Live Feed)

Shows:

  • Domain being accessed
  • App making request
  • Status (Allowed/Blocked)
  • Timestamp

Access Query Logs:

Configure → Logs → Network Logs

Filter Logs:

Logs → Filter icon → Select:
- Blocked only
- Allowed only
- Specific app
- Time range

Example: Find What’s Draining Battery

1. Configure → Logs
2. Filter by "Last 3 hours"
3. Look for apps with high query count
4. Check if they're making background requests
5. Consider blocking background access

8. Block Connections by IP

Block Specific IP Address:

Configure → Apps → Universal Rules → IP Rules
Add IP → Block

Block IP Range:

IP Rules → Add Range
Example: 192.168.1.0/24

9. Set Up DNS Proxy

Enable Local DNS Proxy:

Configure → DNS → DNS Proxy Mode

Benefits:

  • Use Rethink with other VPNs
  • Compatible with enterprise VPNs
  • Lower battery usage

Configuration:

1. Configure → DNS
2. Toggle "DNS Proxy" mode
3. Note the local proxy address (usually 127.0.0.1)
4. Configure system/other apps to use this proxy

10. Per-App DNS Settings

Set Different DNS for Specific App:

Configure → Apps → Select App → DNS Settings

Example: Use Cloudflare Only for Browser

1. Configure → Apps → Chrome
2. Tap DNS option
3. Select "Cloudflare"
4. Save
5. Chrome now uses separate DNS from other apps

Advanced Features

WireGuard VPN Integration

Add WireGuard Config:

Configure → Proxy → WireGuard
Import .conf file OR Enter manually

Use Rethink DNS + WireGuard Together:

1. Add WireGuard configuration
2. Enable WireGuard
3. Rethink will route traffic through VPN
4. DNS filtering still active

On-Device DNS Server

Use Rethink as DNS Server for Other Devices:

Configure → DNS → On-Device Server
1. Enable "DNS Server"
2. Note IP address (e.g., 192.168.1.5:5354)
3. Configure other devices to use this DNS

Example: Use Phone as Network-wide DNS

1. Ensure phone has static IP
2. Enable On-Device Server
3. On router, set DNS to phone's IP
4. All network traffic filtered through Rethink

Automatic Backups

Enable Auto-Backup:

Settings → Backup & Restore → Auto-backup
Select frequency (Daily/Weekly)

Manual Backup:

Settings → Backup & Restore → Backup Now

Restore Configuration:

Settings → Backup & Restore → Restore → Select backup file

Logs & Monitoring

Understanding Log Entries

Log Entry Components:

[Timestamp] [App] [Domain] [Status] [Latency]

Status Indicators:

  • 🟢 Allowed - Request permitted
  • 🔴 Blocked - Request blocked by blocklist
  • ⚫ Filtered - Blocked by custom rule
  • 🟡 Bypassed - Whitelisted domain

Export Logs

Export Network Logs:

Configure → Logs → 3-dot menu → Export
Choose format: CSV / JSON

Use Cases:

  • Analyze network usage patterns
  • Identify misbehaving apps
  • Debug connectivity issues

Troubleshooting

Common Issues & Solutions

1. Internet Not Working After Enabling Rethink

Solution:

1. Check DNS is configured correctly
2. Try switching DNS provider (Configure → DNS)
3. Clear DNS cache: Settings → Clear DNS cache
4. Disable all blocklists temporarily
5. Check if specific app needs whitelisting

2. App Not Working / Connection Issues

Solution:

1. Check if app is blocked in firewall
   Configure → Apps → Find app → Enable
2. Check logs for blocked domains
   Logs → Filter by app → Look for blocks
3. Whitelist required domains
4. Disable blocklists one-by-one to identify issue

Example: Banking App Not Working

1. Configure → Logs
2. Filter by banking app
3. Look for blocked domains (red entries)
4. Whitelist those domains:
   Configure → DNS → Domain Rules → Whitelist
5. Add each blocked domain
6. Test app again

3. High Battery Drain

Solution:

1. Enable Battery Optimization
   Settings → Battery Saver → Enable
2. Reduce log retention
   Settings → Logs → Reduce retention period
3. Use DNS Proxy mode instead of VPN mode
4. Disable real-time monitoring if not needed

4. Cannot Use with Another VPN

Solution:

1. Switch to DNS Proxy mode
   Configure → DNS → DNS Proxy
2. Or integrate WireGuard directly in Rethink
   Configure → Proxy → WireGuard → Add config

5. Blocklists Not Updating

Solution:

1. Configure → DNS → Blocklists
2. Pull down to refresh
3. Check internet connectivity
4. Clear cache: Settings → Clear cache
5. Re-download lists: Long-press list → Update

Best Practices

Daily Use Recommendations

1. Optimal Blocklist Setup

For balanced blocking + performance:
✓ OISD Basic
✓ Hagezi Pro
✓ 1Hosts (Pro)

Update frequency: Weekly

2. App-Specific Rules

Block Social Media Background Access:

Configure → Apps → Instagram/Facebook/Twitter
Block when screen off
Reduces data usage by 30-50%

Allow Critical Apps:

Whitelist:
- Banking apps
- Authentication apps (2FA)
- Work-related apps
- Video calling apps

3. Battery Optimization

Settings for Best Battery Life:

1. Settings → Battery Saver → ON
2. Settings → Logs → Retention: 24 hours
3. Use DNS Proxy if possible
4. Disable real-time network monitor
5. Reduce blocklist count (use only essential lists)

4. Security-Focused Configuration

DNS: Quad9 or NextDNS
Blocklists:
✓ Hagezi Pro
✓ URLHaus Malware
✓ Phishing Army
✓ Dan Pollock's Hosts

Firewall:
- Block unknown apps by default
- Whitelist only trusted apps
- Enable "Block when screen off" for social apps

5. Privacy-Focused Configuration

DNS: Mullvad DNS or Quad9
Blocklists:
✓ All tracker lists
✓ Privacy blocklists
✓ Analytics blocklists

Settings:
- Disable logs or set 1-hour retention
- Use DNS-over-HTTPS
- Enable "Block third-party DNS"

Quick Reference Commands

Most Used Operations

Action Path Quick Tip
Enable/Disable Home → Power button Use Quick Settings tile
Block app Configure → Apps → Toggle Swipe app left for quick block
View logs Configure → Logs Filter by app for specific issues
Whitelist domain Configure → DNS → Domain Rules Long-press log entry to whitelist
Change DNS Configure → DNS → Select Test different providers for speed
Export logs Logs → Menu → Export Use for debugging
Backup config Settings → Backup Do before major changes

Useful Shortcuts

Quick Actions from Logs

From Network Log Entry:

  • Long-press domain → Whitelist/Blacklist
  • Tap app name → Go to app settings
  • Tap domain → Copy domain name

Notification Controls

Quick Actions in Notification:

  • Pause/Resume protection
  • View active queries count
  • Access app quickly

Performance Tips

Optimize for Speed

  1. Use Fewer Blocklists:

    Fewer lists = Faster DNS resolution
Recommended: 3-5 well-maintained lists

  2. Choose Fast DNS:

    Test DNS providers:
Settings → Network Test → DNS Speed Test

  3. Clear Cache Regularly:

    Settings → Clear DNS Cache (weekly)

  4. Use DNS Proxy Mode:

    Lower overhead than full VPN mode
Better for battery and performance

Automation & Integration

Tasker Integration (Advanced)

Auto-enable Strict Mode at Night:

Tasker Task:
1. Send Intent: com.celzero.bravedns.FIREWALL_MODE
2. Extra: mode=strict
3. Time: 11 PM - 6 AM

Auto-disable for Specific WiFi:

When connected to trusted WiFi:
Send Intent to disable Rethink temporarily

Update & Maintenance

Keep Rethink Updated

Check for Updates:

Settings → About → Check for updates

Update Blocklists:

Configure → DNS → Blocklists → Pull to refresh
Automatic updates: Weekly (configurable)

Clean Old Logs:

Settings → Logs → Clear Old Logs
Keeps app lightweight

Example Workflows

Workflow 1: Setting Up for First Time

1. Install Rethink DNS
2. Launch → Grant VPN permission
3. Select "Rethink DNS" mode
4. Enable blocklists:
   - OISD Basic
   - Hagezi Pro
5. Enable protection (Power button)
6. Test browsing → Verify ads blocked
7. Configure → Apps → Review critical apps → Whitelist if needed
8. Done!

Workflow 2: Troubleshooting App Issues

1. User reports: "Banking app not working"
2. Configure → Logs
3. Filter by banking app name
4. Identify blocked domains (red entries)
5. Configure → DNS → Domain Rules → Whitelist
6. Add each blocked domain
7. Clear app cache
8. Test banking app
9. If still issues, temporarily disable blocklists
10. Re-enable lists one-by-one to find culprit

Workflow 3: Battery Optimization

1. Settings → Battery Saver → Enable
2. Configure → Apps → Social Media apps
3. For each: Enable "Block when screen off"
4. Settings → Logs → Retention: 6 hours
5. Monitor battery usage over 24 hours
6. Adjust blocklist count if still high drain

Workflow 4: Privacy-First Setup

1. Configure → DNS → Select "Mullvad DNS"
2. Configure → DNS → Blocklists → Enable:
   - All tracker lists
   - Analytics lists
   - Hagezi Privacy
3. Settings → Logs → Retention: 1 hour (or disable)
4. Configure → Apps → Block all by default
5. Whitelist only essential apps
6. Settings → Connectivity → Block IPv6 (optional)
7. Enable "Block third-party DNS"

Community & Support

Getting Help

  • GitHub Issues: Report bugs, request features
  • Telegram: Join community for quick help
  • Documentation: https://docs.rethinkdns.com
  • Reddit: r/rethinkdns (community discussions)

Contributing

  • Report Issues: GitHub Issues tracker
  • Translations: Help translate the app
  • Blocklists: Suggest new lists
  • Code: Submit pull requests

Important Notes

⚠️ VPN Limitation: Android allows only one VPN at a time. Use DNS Proxy mode if you need another VPN.

⚠️ Enterprise Networks: May conflict with corporate VPN. Use DNS Proxy or disable Rethink on work network.

⚠️ Battery: VPN mode uses more battery than DNS Proxy mode. Optimize settings for daily use.

⚠️ Privacy: Logs stored locally on device. Set retention period based on your needs.

✅ Open Source: Fully auditable code, no telemetry, no data collection.

Version Information

Current Guide Version: 2025 Rethink DNS Latest: v0.5.5+ (Check GitHub for current version) Last Updated: Based on latest available documentation as of 2025

License

This guide is created for educational purposes. Rethink DNS is licensed under Apache License 2.0.

Official Resources:

End of Guide


---

## How to Use This Guide - Explained

### For Beginners

**Start Here:**
1. Read the "Overview" and "Key Features" sections first
2. Follow the "Installation & Setup" guide step-by-step
3. Learn the "Essential Daily Commands" - focus on commands 1-5 first
4. Use "Workflow 1" as your first-time setup guide

**Example Scenario: Complete Beginner Setup**

Day 1 - Initial Setup:

  • Install app from Play Store
  • Follow “First Launch Configuration”
  • Enable with default settings (Rethink DNS mode)
  • Browse normally and observe blocked ads

Day 2 - Basic Customization:

  • Learn Command #2: Check Current Status
  • Review what’s being blocked
  • Practice Command #3: Block/Unblock specific apps
  • Example: Block Instagram when screen off

Day 3 - DNS Exploration:

  • Learn Command #4: DNS Configuration
  • Try different DNS providers (Cloudflare, Quad9)
  • Notice speed differences
  • Stick with fastest one

Day 4 - Fine-tuning:

  • Learn Command #6: Whitelist/Blacklist
  • Fix any broken websites/apps
  • Add necessary domains to whitelist

Day 5 - Monitoring:

  • Learn Command #7: Monitor Network Activity
  • Watch real-time queries
  • Understand what apps are doing

### For Intermediate Users

**Focus On:**
- Advanced Features section
- Per-app DNS settings
- Custom blocklist configurations
- WireGuard VPN integration
- Log analysis and export

**Example Use Case: Privacy-Conscious User**

Goal: Maximum privacy with minimal tracking

Setup Process:

  1. Choose privacy-focused DNS (Mullvad/Quad9)
  2. Enable aggressive blocklists:
    • All tracker blocklists
    • Analytics lists
    • Hagezi Privacy Plus
  3. Set up per-app rules:
    • Block social media background access
    • Allow only essential apps
  4. Configure logging:
    • Set 1-hour retention
    • Or disable logs completely
  5. Monitor for a week:
    • Check which domains need whitelisting
    • Fine-tune rules
    • Export logs for analysis

### For Advanced Users

**Explore:**
- On-device DNS server setup
- WireGuard integration for VPN + DNS
- Tasker automation
- Network-wide deployment
- Custom blocklist creation

**Example Use Case: Network Administrator**

Goal: Use Rethink as network-wide DNS filter

Implementation:

  1. Set static IP on Android phone
  2. Enable “On-Device DNS Server”
  3. Configure router to use phone as DNS: Primary DNS: 192.168.1.5:5354
  4. Enable aggressive blocklists
  5. Monitor all network traffic from phone
  6. Create custom rules for family needs
  7. Set up automatic backups
  8. Export logs daily for analysis

---

## Practical Examples in Detail

### Example 1: Stop YouTube Ads (Basic)

Problem: YouTube shows ads

Solution:

  1. Open Rethink DNS
  2. Configure → DNS → Blocklists
  3. Enable: ✓ AdGuard DNS Filter ✓ Hagezi Pro
  4. Apply changes
  5. Close and reopen YouTube
  6. Verify ads are reduced

Note: YouTube ads in the app are harder to block. Browser-based YouTube works better.


### Example 2: Fix Online Banking App (Troubleshooting)

Problem: Banking app shows “Connection Error”

Step-by-step Fix:

  1. Configure → Logs
  2. Open banking app (let it fail)
  3. Go back to logs
  4. Filter by app name “MyBank”
  5. Look for red (blocked) entries
  6. Common blocked domains:
    • analytics.bankname.com
    • cdn.bankname.com
    • secure.auth.bankname.com
  7. For each blocked domain: Configure → DNS → Domain Rules → Whitelist → Add
  8. Clear banking app cache
  9. Test again

Prevention: Add banking apps to whitelist before issues occur


### Example 3: Reduce Mobile Data Usage (Optimization)

Goal: Cut data usage by 40%

Strategy:

  1. Identify data-hungry apps: Configure → Logs → Sort by query count

  2. For social media apps (Facebook, Instagram, Twitter): Configure → Apps → [App Name] Enable “Block when screen off”

  3. For games with ads: Enable aggressive ad-blocking lists Or block game completely

  4. For news apps: Block tracker domains Reduces background prefetching

  5. Monitor for a week: Settings → Statistics Compare data usage before/after

Expected Results:

  • 30-50% reduction in background data
  • Fewer tracking requests
  • Longer battery life (bonus!)

### Example 4: Child-Safe Internet (Parental Control)

Goal: Safe internet for children’s device

Configuration:

  1. DNS Setup: Configure → DNS → Select “CleanBrowsing Family” (Blocks adult content automatically)

  2. Blocklists: ✓ Hagezi Pro ✓ AdGuard DNS Filter ✓ OISD Full ✓ Add “Adult content” lists

  3. App Rules: Configure → Apps → Block by default Whitelist only:

    • Educational apps
    • Approved games
    • Kid-friendly streaming

  4. Time-based Rules (requires Tasker):

    • Restrict social media to 1 hour/day
    • Block gaming apps during homework time
    • Allow only educational apps during study hours

  5. Monitoring:

    • Check logs daily
    • Review accessed domains
    • Adjust rules as needed

  6. Lock Settings: Settings → Security → Set PIN Prevents child from disabling Rethink


### Example 5: Travel/Public WiFi Security (Advanced)

Scenario: Using untrusted public WiFi at airport/hotel

Security Setup:

  1. Before Connecting: Configure → DNS → Select “Quad9” (malware blocking)

  2. Enable Strict Firewall: Configure → Apps → Block all by default Whitelist only:

    • Browser
    • Messaging apps
    • Essential travel apps

  3. Add WireGuard VPN: Configure → Proxy → WireGuard Import your VPN config Enable VPN + Rethink together

  4. Aggressive Blocklists: ✓ URLHaus Malware ✓ Phishing Army ✓ Hagezi Threat Intelligence

  5. Monitoring: Keep logs visible Watch for suspicious domains Common threats:

    • Fake login pages
    • Malware delivery domains
    • Tracking pixels

  6. After Travel: Restore normal configuration Or keep travel profile saved for next time


---

## Visual Guide: Understanding the Interface

### Home Screen Elements

┌─────────────────────────────┐ │ [Power Button] 🟢 │ ← Enable/Disable protection ├─────────────────────────────┤ │ DNS: Rethink DNS │ ← Current DNS provider │ Mode: VPN │ ← Operating mode ├─────────────────────────────┤ │ Network Activity (Live) │ │ ├─ Chrome: google.com ✓ │ ← Real-time queries │ ├─ Instagram: graph.fb ✗ │ ← (✓=allowed, ✗=blocked) │ └─ WhatsApp: wa.me ✓ │ ├─────────────────────────────┤ │ Statistics │ │ Queries: 1,234 │ │ Blocked: 456 (37%) │ │ Allowed: 778 (63%) │ └─────────────────────────────┘ ▼ Scroll for more ▼


### Configure Menu Structure

Configure ├─ DNS │ ├─ DNS Provider (Select/Add) │ ├─ Blocklists (Enable/Disable) │ ├─ Domain Rules (Whitelist/Blacklist) │ └─ DNS Proxy Mode ├─ Apps │ ├─ All Apps (Individual controls) │ ├─ Universal Rules │ └─ IP Rules ├─ Proxy │ ├─ WireGuard │ └─ SOCKS5 └─ Logs ├─ Network Logs ├─ DNS Logs └─ Filters & Export


---

## Keyboard Shortcuts (Android)

While Rethink doesn't have traditional keyboard shortcuts, you can use:

- **Quick Settings Tile**: Swipe down → Tap Rethink tile (toggle on/off)
- **Search**: In app, use search bar to quickly find apps or domains
- **Long-press**: Long-press log entries for quick whitelist/blacklist

---

## Conclusion

This guide covers everything you need to use Rethink DNS effectively in 2025. The app is powerful but intuitive once you understand the core concepts:

1. **DNS filtering** blocks unwanted content at the domain level
2. **Firewall rules** control which apps can access the internet
3. **Logs** help you understand and troubleshoot your network
4. **Customization** lets you fine-tune everything to your needs

**Next Steps:**
- Bookmark this guide for reference
- Start with "Workflow 1" if you're new
- Join the community for updates
- Contribute back by sharing your configurations

**Remember:**
- Start simple, add complexity gradually
- Monitor logs to understand what's happening
- Backup your configuration before major changes
- Update blocklists regularly (weekly recommended)

---

**Sources & Citations:**

1. Official Rethink DNS GitHub Repository: https://github.com/celzero/rethink-app
2. Rethink DNS Official Website: https://rethinkdns.com
3. Documentation: https://docs.rethinkdns.com
4. Community discussions and user reports from GitHub Issues
5. Latest release notes and changelogs (v0.5.5+)

*This guide is community-created and maintained. For official documentation, always refer to the links above.*