Quad9 DNS Ends HTTP/1.1 DoH Support: Complete Guide for 2025

Introduction

Quad9, the privacy-focused DNS resolver, will discontinue DNS-over-HTTPS (DoH) support using HTTP/1.1 by December 15, 2025. This move modernizes infrastructure while keeping security robust. Most modern systems won't be affected, but legacy equipment may need updates.

Understanding the Protocol Change

The retirement of HTTP/1.1 for DoH is a key step in Quad9's modernization. This older protocol lacks the performance of HTTP/2 and HTTP/3. By focusing on newer standards, Quad9 enhances DNS resolver capabilities and features.

Modern browsers like Chrome, Firefox, and Safari use HTTP/2 or later for DoH, so most users won't notice changes. Updated OSes on Windows, macOS, and Linux have adopted modern protocols for network monitoring and DNS resolution.

Impact on Legacy Systems

Specialized networking equipment, especially some MikroTik routers using HTTP/1.1, may lose Quad9 DoH unless updated. Network admins should prepare by exploring router configuration tools or adjusting DNS settings.

This highlights the need for updated encryption tools. Quad9 will still support traditional DNS and DNS-over-TLS, but DoH will only use HTTP/2 and HTTP/3 after December 2025.

Pros and Cons

Advantages

• Better performance with HTTP/2 and HTTP/3
• Enhanced security via updated encryption
• Improved resource allocation for Quad9
• Alignment with current browser and OS standards
• Promotes up-to-date network security practices

Disadvantages

• Potential disruption for legacy equipment users
• Configuration changes needed for affected routers
• Limited impact on outdated infrastructure

Conclusion

Quad9's sunset of HTTP/1.1 DoH is a necessary evolution for encrypted DNS. While some adjustments are needed, it strengthens privacy and performance, making Quad9 a valuable privacy tool. Verify system compatibility before the deadline to ensure uninterrupted service.