Your ISP’s DNS resolver logs every website you visit, selling this data to data brokers. Switching to a privacy-focused DNS resolver takes 90 seconds and immediately blocks this tracking. However, DNS resolver privacy is murky—some claim “no logging” while keeping 24-hour retention. This guide compares actual logging practices, speed benchmarks, and configuration across Cloudflare 1.1.1.1, Quad9, NextDNS, and AdGuard based on 2026 published policies and independent testing.

How DNS Leaks Your Browsing

When you visit google.com, your device asks a DNS resolver: “What’s the IP address for google.com?” The resolver logs your IP address, the domain you requested, the time, and your device fingerprint. This data reveals:

• Every website you visit (exact timing)
• Search queries (if you type in address bar)
• Failed domain lookups (showing typos in addresses)
• Your location (via IP geolocation)
• Your browsing habits (correlated across weeks/months)

ISP DNS logging examples (real practice):

• Comcast: Keeps DNS logs for 6 months, sells to data brokers
• AT&T: Sells DNS data unless you explicitly opt out
• Verizon: Profiles users with DNS data, partners with ad networks

Switching DNS resolvers is one of the highest-impact privacy moves you can make with zero effort.

DNS Resolver Privacy Comparison

Important caveat: “No-log” claims are only credible if independently verified. 2026 updates:

• Cloudflare added WARP encryption (encrypts DNS queries themselves)
• NextDNS improved transparency with usage analytics
• Quad9 passed privacy audits from 3rd-party firms

Detailed Analysis: Which Resolver to Use

Cloudflare 1.1.1.1 (Fastest, Balanced)

Use if: You want fastest speeds, ISP blocking bypass, or simplest setup

DNS addresses:

IPv4 (Primary): 1.1.1.1
IPv4 (Secondary): 1.0.0.1

IPv6 (Primary): 2606:4700:4700::1111
IPv6 (Secondary): 2606:4700:4700::1001

DoH (DNS-over-HTTPS): https://dns.cloudflare.com/dns-query

Privacy analysis:

Cloudflare claims:

• Queries deleted immediately from logs
• Does NOT sell data to advertisers
• Stores only aggregated, anonymized statistics

However:

• WARP (their VPN) logs your traffic encrypted (you must opt in)
• Free service = you’re the product in other ways (anonymized data sold)
• Quarterly warrant canary (hasn’t received government requests yet)

Speed testing (independent, March 2026):

Cloudflare 1.1.1.1:
- North America: 8-15ms
- Europe: 12-25ms
- Asia: 30-50ms
- Australia: 45-90ms
Average: 35ms globally

Best for:

• Blocking ISP censorship (Cloudflare routes around ISP blocks)
• Raw speed (fastest resolver)
• Simplicity (works globally without additional setup)

Configuration (macOS):

System Settings → Network → Wi-Fi → Details →
DNS Servers

Remove existing DNS servers
Add: 1.1.1.1
Add: 1.0.0.1

Apply

Limitations:

• No ad blocking (must use browser extension separately)
• Limited domain filtering
• Free plan logs anonymized data (if you care about zero-logging)

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:

• Deletes DNS queries immediately (verified)
• DNSSEC validation prevents DNS spoofing
• Funded by non-profit (not venture capital), so no investor pressure to monetize user data
• Quarterly warrant canary (has NEVER received government requests)
• Published transparency reports (publicly available logs of data requests)

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:

• Users wanting malware protection without extra software
• Privacy-conscious users (non-profit, warrant canary excellent)
• Organizations wanting free centralized DNS security

Limitations:

• Slightly slower than Cloudflare (security checks add latency)
• Blocks some legitimate services (over-aggressive filtering can be toggled)
• Limited per-device customization

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:

• Stores queries for 3 months by default (you can reduce to 1 day or disable)
• Does NOT sell data to third parties
• Publishes usage dashboard showing what’s filtered on YOUR account
• Monthly transparency reports (can request data requests from governments)
• Parent company (Nextdoor) has privacy controversy, but DNS product is separate

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:

• Families wanting granular per-child blocking
• Remote teams (corporate allow-lists per employee)
• Power users wanting detailed usage analytics
• Organizations wanting dashboard visibility

Cost:

• Free plan: 1 device, 300K queries/month
• $2/month: 1 device, unlimited queries
• $4/month: 5 devices, unlimited queries

Limitations:

• Requires login/account creation (less anonymous than Cloudflare)
• Moderate speed (slightly slower than competitors)
• Data retention controversial (you must opt out of logging)

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:

• Queries deleted immediately (no retention)
• AdGuard owns all servers (not relying on third-party cloud providers)
• No account required (zero tracking)
• Does NOT collect user data for targeting
• Limited transparency reports (not as detailed as Quad9)

However:

• Company is based in Cyprus (subject to EU privacy laws, but less US oversight)
• Less transparent than Quad9 (warrant canary not published)
• Private company (not non-profit like Quad9)

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:

• Ad blocking without account (maximum privacy)
• Users on privacy-conscious networks
• Android devices (particularly good implementation)
• Balanced speed + blocking

Limitations:

• No per-device customization (same filtering for all)
• Less detailed usage analytics
• Newer service (fewer independent audits than Quad9)

Performance Comparison: Real-World Benchmarks

Testing with thousands of queries (March 2026):

DNS query response time (99th percentile):

Winner for speed: Cloudflare (no security filtering overhead)

Winner for balance: AdGuard (good speed despite filtering)

Blocking Effectiveness

Testing against common ad/tracker domains:

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:

• Visit https://1.1.1.1/help/ (shows current resolver)
• Visit https://dnsleaktest.com/ (tests for DNS leaks)
• Visit https://dns.nextdns.io/ (shows if NextDNS active)

Related Reading

• Privacy-Focused DNS Providers Comparison 2026
• Privacy-Focused DNS Providers Comparison 2026 — Privacy
• Encrypted Dns Messaging Combination How To Layer Privacy Pro
• Home Network Privacy Pihole Dns Filtering Guide 2026
• Best Anonymous Email Service 2026: A Privacy-Focused Guide

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