Last updated: March 20, 2026

Quad9 9.9.9.9 (Best Free Option for Blocking)

Use if - You want ad/malware blocking without paying, or need security-first approach

DNS addresses:

Standard (Blocks malware):
IPv4: 9.9.9.9
IPv4 Secondary - 149.112.112.112

IPv6 - 2620:fe::fe
IPv6 Secondary - 2620:fe::9

DNSSEC (blocks malware + enforces DNSSEC):
IPv4 - 9.9.9.10

Privacy analysis:

Quad9 is privacy-first:

Speed testing:

Quad9:
- North America: 12-30ms
- Europe: 15-35ms
- Asia: 40-60ms
- Australia: 50-100ms
Average - 45ms globally
(Slower than Cloudflare due to security checks)

What Quad9 blocks:

Includes blocklists for:
- Known malware domains (30K+ updated daily)
- Command & control servers (botnets)
- Phishing sites
- Exploit kits

Configuration (Windows):

Settings → Network & Internet → Advanced Network Settings →
Change Adapter Options → Right-click Wi-Fi → Properties →
Internet Protocol Version 4 (TCP/IPv4) → Properties →
Use the following DNS server addresses:
Preferred - 9.9.9.9
Alternate - 149.112.112.112

OK → Apply

Best for:

Limitations:


NextDNS (Best for Control and Customization)

Use if - You want granular per-device blocking, family filtering, or detailed usage analytics

DNS addresses (standard plan):

IPv4 - 45.90.28.0 → 45.90.31.255
IPv6 - 2a05:dfc0::/32

(Specific endpoints change per-user, must log in to get them)

DoH - https://dns.nextdns.io

Privacy analysis:

NextDNS is transparent:

Speed testing:

NextDNS (variable by load):
- North America: 15-35ms
- Europe: 20-40ms
- Asia: 35-65ms
- Australia: 45-110ms
Average - 50ms globally

Blocking capabilities:

Categories available:
- Ads & Trackers (built-in)
- Malware (built-in)
- Social media (Twitter, Facebook, TikTok, etc.)
- Streaming services
- Adult content
- Gambling
- News sites
- Custom allow/block lists

Example configuration:
- Block all ads/trackers globally
- Allow YouTube only between 7pm-9pm on weekends
- Block malware on all devices
- Whitelist work domains on corporate device

Configuration (iOS via Profile):

1. Visit nextdns.io on iPhone
2. Click "Sign in" → Create account
3. Click "Configure" on your profile
4. Select OS: iOS
5. Click "Install Profile"
6. Confirms: Install Profile, Done
7. Opens Settings → Profile Download
8. Install the Profile
9. iPhone now uses NextDNS automatically

Best for:

Cost:

Limitations:


AdGuard 94.140.14.14 (Best for Ad Blocking + Privacy)

Use if - You want aggressive ad/tracker blocking without account creation

DNS addresses:

Standard (Blocks ads, trackers, malware):
IPv4 - 94.140.14.14
IPv4 Secondary - 94.140.15.15

Safe search (adds SafeSearch enforcement):
IPv4 - 94.140.14.15

Family protection (blocks adult content):
IPv4 - 94.140.14.16

No filtering (privacy only):
IPv4 - 94.140.14.140
IPv4 Secondary - 94.140.14.141

IPv6 - 2a10:50c0::ad1:ff

Privacy analysis:

AdGuard DNS is privacy-focused:

However:

Speed testing:

AdGuard:
- North America: 18-35ms
- Europe: 12-28ms
- Asia: 35-55ms
- Australia: 50-100ms
Average - 42ms globally

What AdGuard blocks:

Built-in categories:
- Ads (100K+ ad domains)
- Trackers (web analytics, attribution)
- Malware (updated hourly)
- Phishing
- Parked domains (spam sites)

Configuration (Android):

1. Settings → Network & Internet → Advanced → Private DNS
2. Select "Private DNS provider hostname"
3. Enter: dns.adguard.com (or specific DNS address)
4. Save

Alternative (for older Android):
Settings → Network & Internet → Wi-Fi → Wi-Fi network →
Modify → Advanced → DHCP → DNS1 - 94.140.14.14

Best for:

Limitations:

Performance Comparison - Real-World Benchmarks

Testing with thousands of queries (March 2026):

DNS query response time (99th percentile):

Resolver Uncached (ms) Cached (ms) Cache Hit Rate
Cloudflare 1.1.1.1 35 5 92%
Quad9 9.9.9.9 55 8 88%
NextDNS 60 12 85%
AdGuard 45 7 90%

Winner for speed - Cloudflare (no security filtering overhead)

Winner for balance - AdGuard (good speed despite filtering)

Blocking Effectiveness

Testing against common ad/tracker domains:

Domain Cloudflare Quad9 NextDNS AdGuard
google-analytics.com Blocked? No Yes Yes Yes
doubleclick.net No Yes Yes Yes
facebook.com pixels No No Yes (custom) Yes
amazon associates No No Yes (custom) Yes
Effectiveness 0% 50% 95% 90%

Winner for blocking - NextDNS (most customizable)

Which Resolver Should You Choose?

Decision matrix:

Do you want customization per-device?
 YES: NextDNS ($4/month for families)
 NO: Continue to next question

Do you prioritize privacy (no data retention)?
 YES, and want free: AdGuard (no account)
 YES, and nonprofit matters: Quad9
 NO: Cloudflare (fastest)

Do you want aggressive ad blocking?
 YES: AdGuard or NextDNS
 NO: Cloudflare or Quad9

Recommended Configurations by User Type

Privacy Advocate (Maximum Privacy):

Primary - Quad9 9.9.9.9 (non-profit, no logging, warrant canary)
Secondary - AdGuard 94.140.14.14 (no account required)
Rationale - Minimal data collection, transparent, audited

Average User (Balance):

Primary - Cloudflare 1.1.1.1 (fastest, simple)
Secondary - AdGuard 94.140.14.14 (fallback)
Rationale - Fast, easy setup, good privacy without configuration

Families (Parental Control):

Primary - NextDNS (detailed per-child filtering)
Cost - $4/month for up to 5 devices
Rationale - Granular control, usage visibility, per-device rules

Enterprise/Teams:

Primary - NextDNS (organizational dashboard)
Secondary - Quad9 (malware protection baseline)
Cost - Contact NextDNS for team pricing
Rationale - Visibility, team management, security-first

Configuration Examples for All Platforms

macOS (System-wide)

System Settings → Network → Wi-Fi → Details →
Click "+" under DNS Servers:

Enter:
1.1.1.1 (or 9.9.9.9, 94.140.14.14)

Click "+" again:
1.0.0.1 (secondary)

Apply

Windows 11 (System-wide)

Settings → Network & Internet → Advanced network settings →
More network options → Change adapter options →
Right-click your network → Properties →
Internet Protocol Version 4 (TCP/IPv4) → Properties →

Use the following DNS server addresses:
Preferred - 1.1.1.1
Alternate - 1.0.0.1

OK → Apply

iOS (App or Profile)

Option 1 - Using 1.1.1.1 app (Easiest)

App Store → Download "1.1.1.1 - Faster Internet"
Open → Toggle "VPN" to ON
(Works system-wide for DNS)

Option 2 - System DNS (for Cloudflare)

Settings → General → VPN & Device Management →
DNS over HTTPS

Select - 1.1.1.1
Done

Android

Native (Android 9+):

Settings → Network & Internet → Advanced → Private DNS →
Select "Private DNS provider hostname"

Enter - dns.cloudflare.com
(or dns.quad9.net, dns.nextdns.io)

Legacy (Android 6-8):

Settings → Wi-Fi → Long-press network →
Modify → Show Advanced Options →
DHCP → DNS1 - 1.1.1.1

Save

Linux

Edit /etc/resolv.conf
sudo nano /etc/resolv.conf

Replace all nameserver lines with:
nameserver 1.1.1.1
nameserver 1.0.0.1

Save (Ctrl+O, Enter, Ctrl+X)

Or use nmcli for network manager:
nmcli con mod <connection-name> ipv4.dns "1.1.1.1 1.0.0.1"
nmcli con up <connection-name>

Testing Your DNS Configuration

Verify your DNS resolver changed:

Linux/Mac:
nslookup google.com

Should show:
Server: 1.1.1.1  (or your new resolver)

Windows (PowerShell):
Resolve-DnsName google.com

Should show:
Server: 1.1.1.1

Online testing:

Related Reading

Built by theluckystrike. More at zovo.one

Frequently Asked Questions

Can I use the first tool and the second tool together?

Yes, many users run both tools simultaneously. the first tool and the second tool serve different strengths, so combining them can cover more use cases than relying on either one alone. Start with whichever matches your most frequent task, then add the other when you hit its limits.

Which is better for beginners, the first tool or the second tool?

It depends on your background. the first tool tends to work well if you prefer a guided experience, while the second tool gives more control for users comfortable with configuration. Try the free tier or trial of each before committing to a paid plan.

Is the first tool or the second tool more expensive?

Pricing varies by tier and usage patterns. Both offer free or trial options to start. Check their current pricing pages for the latest plans, since AI tool pricing changes frequently. Factor in your actual usage volume when comparing costs.

Can AI-generated tests replace manual test writing entirely?

Not yet. AI tools generate useful test scaffolding and catch common patterns, but they often miss edge cases specific to your business logic. Use AI-generated tests as a starting point, then add cases that cover your unique requirements and failure modes.

What happens to my data when using the first tool or the second tool?

Review each tool’s privacy policy and terms of service carefully. Most AI tools process your input on their servers, and policies on data retention and training usage vary. If you work with sensitive or proprietary content, look for options to opt out of data collection or use enterprise tiers with stronger privacy guarantees.