DNS Benchmark is free and open source. It is a desktop app that finds the fastest DNS resolver for your internet connection, so you can pick the one that makes everything you do online feel a little snappier. There is no cost, no account, and no tracking, and the full source code is available under the MIT license.
Why DNS speed matters
Every website visit, email, and cloud app starts with a DNS lookup. A slow or unreliable resolver adds delay to all of it, and the default one your ISP or router hands out is rarely the best choice. Switching to a faster, more reliable resolver is one of the simplest improvements you can make to a network, but only if you measure first.
What it does
DNS Benchmark tests the DNS servers your computer is already configured to use, along with well-known public resolvers such as Cloudflare, Google, Quad9, and OpenDNS. You can also add your own servers. Each one is tested over all four of the protocols in common use today:
- UDP and TCP, classic DNS on port 53
- DNS-over-TLS (DoT), encrypted DNS on port 853, with certificates verified
- DNS-over-HTTPS (DoH), encrypted DNS over HTTPS on port 443
Servers are tested in parallel, and the list re-sorts itself fastest-first as results arrive. Select any server to see detailed statistics, including median, mean, minimum, maximum, and packet loss.
Built to give honest numbers
A benchmark is only useful if the results can be trusted. DNS Benchmark alternates between a popular domain and a random subdomain, so you see both cached and uncached performance. It also rotates the order of protocols and uses a different name for each, so one protocol never warms the cache for another. Connection setup time is reported separately instead of being mixed into lookup latency, and servers that drop more than 10% of lookups are ranked below the reliable ones.
Get it
DNS Benchmark is a native GTK 4 application for Linux, written in C++. It also includes a command-line mode for headless use and scripting. You can build it from source on Ubuntu or Debian in a few minutes. The repository has the instructions.
Download DNS Benchmark on GitHub. Because it is open source, you are welcome to read the code, report problems, suggest improvements, or send a pull request.