All web browsing starts with a DNS query to find the IP address for the desired service or website. For much of the internet’s history, this query is sent in the clear. DNS-over-HTTPS (DoH) plugs this privacy leak by encrypting the DNS messages, so no one on the network, not your internet service provider or a free public WiFi provider, can eavesdrop on your browsing.
In 2020, Firefox became the first browser to roll out DoH by default, starting in the United States and in 2023, we announced the Firefox DoH-by-default rollout in Canada, powered by our trusted partner, the Canadian Internet Registration Authority (CIRA).
This year, we’ve built on that foundation and delivered major performance improvements and mobile support, ensuring more Firefox users benefit from privacy without compromise.
Introducing DoH for Android
After bringing encrypted DNS protection to millions of desktop users, we’re now extending the same to mobile. Firefox users who have been waiting for DoH on Android can now turn it on and browse with the same privacy protections as on their desktops.
Starting with this week’s release of Firefox 143 for Android, users can choose to enable DoH in Firefox on their mobile devices by selecting “Increased Protection” DoH configuration. Performance testing with Firefox DoH partners is currently underway. If DoH is as fast as we expect, we plan to enable it by default for Android users in certain regions, similar to desktop users. Until then, these configuration options provide you the choice to opt in early.
Enable DoH in Firefox on Android
DoH performance breakthroughs in 2025
DNS resolution speed is critical to the browsing experience — when web pages involve multiple DNS queries, the speed difference compounds and can cause page loads to be slow. Since we first rolled out DoH in Canada, we’ve worked closely with CIRA for reliability and performance measurements. Through our strong collaboration with them and their technology partner Akamai, Firefox DoH lookups are now 61% faster year-to-date for the 75th percentile.
With these performance improvements, DoH resolution time is now within a millisecond or two of native DNS resolution. This is a big win because Firefox users in Canada now get the privacy of encrypted DNS with no performance penalty.
Although the investigation and analysis started with the desire to improve DoH in Firefox, the benefits didn’t end there. Our collaboration also improved CIRA DoH performance for many of its DNS users, including Canadian universities, as well as other DNS providers relying on CIRA’s or Akamai’s server implementations.
This is a win not just for Firefox users, but for the many other users around the globe.
Robust privacy on your terms
We have always approached DoH with an emphasis on transparency, user choice, and strong privacy safeguards. Firefox gives users meaningful control over how their DNS traffic is handled: Users can opt out, choose their own resolver, or adjust DoH protection levels, and Firefox makes it clear what DoH is doing and why it matters.
Firefox enforces strict requirements for DNS resolvers before trusting them with your browsing. Not every DNS provider can become a DoH provider in Firefox — only those that meet and attest to Mozilla’s rigorous Trusted Recursive Resolver (TRR) policy through a legally binding contract.
Prioritizing your privacy and speed
Our work with DoH this year shows what’s possible when privacy and performance go hand-in-hand. We’ve proven that encrypted DNS can be fast, reliable, and available on desktop and Android. Just as importantly, we’ve shown that partnerships grounded in open standards and accountability can deliver benefits not only to Firefox users but to the wider internet.
As we look forward, our commitment stays the same: Privacy should be the default, speed should never be a compromise, and the web should remain open and accessible to everyone. Choosing Firefox means choosing a browser that is built for you and for a better internet.