Ookla says the connection is 400 Mbps and the browser still feels slow. The bottleneck is often not bandwidth but DNS: the resolver assigned by the ISP takes 200 ms to hand back a hostname, and every page that loads sixteen third-party assets pays that tax sixteen times over. The best apps for DNS speed testing measure resolution latency from your PC to a list of public resolvers, rank them, and often let you switch to the fastest one in a click. We picked eight tools that cover Windows, macOS, and Linux and both the “which resolver” and the “why is DNS slow at all” questions.
What to look for
Six things matter when picking a DNS benchmark.
- Tests from your actual PC, so results reflect your ISP’s routing, not a datacentre’s
- Compares cached and uncached queries, since first-hit latency is what breaks browsing
- Includes DoT and DoH resolvers, not only the traditional plaintext ones on port 53
- Ranks resolvers on reliability, not only median speed
- Lets you save the top choice as the system resolver without a manual
resolv.confedit - Runs offline once installed
Quick comparison table
| App | Best for | Interface | Free plan | Standout feature |
|---|---|---|---|---|
| GRC DNS Benchmark | Windows users who want a definitive answer | Windows GUI | Free | Full statistical table with jitter |
| NameBench | macOS and Linux CLI users | Python CLI | Free (open source) | Cross-references your browser history |
| DNSPerf | Live monitoring of public resolvers | Web dashboard | Free tier | Global uptime data |
| dnsperf | Benchmarking your own resolver | Terminal | Free (open source) | Simulates traffic patterns |
| NextDNS CLI | Testing NextDNS from your machine | Terminal | Free for 300k queries/mo | Lightweight probe |
| Cloudflare 1.1.1.1 GUI | Quick swap to Cloudflare with a UI | Native app | Free | One-click DoH setup |
| DNS Jumper | Windows tinkerers | Windows GUI | Free | Applies a change without a reboot |
| dnstop | Diagnosing DNS chatter | Terminal | Free (open source) | Shows which app is querying |
The apps
1. GRC DNS Benchmark, best for Windows
GRC DNS Benchmark is a small standalone .exe from Steve Gibson’s site. It probes every resolver in the built-in list plus any you add, records cached and uncached latency, and calculates a reliability score. The results table breaks down each resolver’s min / avg / max response time, so you can spot the one whose worst case is 800 ms even though the average is fine.
Where it falls short: Windows only. Also does not test DoH or DoT, only port 53. For encrypted DNS testing pair it with dnsperf.
Pricing:
- Free
- Paid: none
Platforms: Windows
Download: grc.com/dns/benchmark.htm
Bottom line: Twenty years old, still the definitive Windows benchmark. Ten minutes to run, one clear answer at the end.
2. NameBench, best for macOS and Linux
NameBench was Google’s DNS benchmark project. Original development stopped, but forks keep it alive. Cross-references the resolvers you test against a sample of your browser history so the timings reflect the domains you actually visit, not a generic top-1000 list.
Where it falls short: Python 2 in the original release. Recent forks target Python 3 but the UX still shows its age.
Pricing:
- Free
- Paid: none
Platforms: macOS, Linux, Windows
Download: github.com/google/namebench (or a maintained fork)
Bottom line: The right pick when your Windows friend runs GRC and you want the same answer on a Mac.
3. DNSPerf, best for real-world resolver data
DNSPerf publishes monthly rankings for every public resolver, plus a live dashboard of query success rates and latency by region. Useful for narrowing the shortlist before running your own benchmark: no point testing a resolver that has a 40 ms deficit to Cloudflare in your city.
Where it falls short: Not a local benchmark. Their data reflects average performance from their monitoring nodes, not from your specific ISP.
Pricing:
- Free tier: read-only dashboards
- Paid: commercial API from custom pricing
Platforms: Any browser
Download: dnsperf.com/dns-resolvers
Bottom line: Consult DNSPerf before running a local benchmark. Rules out the low-performers so you test fewer candidates.
4. dnsperf CLI, best for stress-testing a resolver
dnsperf (the command-line tool from Nominum, now DNS-OARC) fires configurable query streams at any resolver and reports throughput and latency percentiles. Useful when you want to know how a resolver behaves under load, not only at idle. Also the standard way to benchmark a self-hosted Unbound or Pi-hole.
Where it falls short: Requires a query file, which is not obvious to first-time users. Sample query lists are available from OARC.
Pricing:
- Free
- Paid: none
Platforms: Linux, macOS, BSD; Windows via WSL
Download: github.com/DNS-OARC/dnsperf
Bottom line: The tool of choice for load-testing rather than idle-testing. Pair with GRC for a complete picture.
5. NextDNS CLI, best for testing NextDNS from your machine
NextDNS CLI turns NextDNS into a local DoH proxy and, in the process, gives you a client that reports resolution timings for its own resolver. Useful for confirming that switching to NextDNS actually helped, rather than trusting the marketing chart.
Where it falls short: Only tests NextDNS’s own performance. For a comparative benchmark, pair with GRC or dnsperf.
Pricing:
- Free: 300,000 queries/month
- Paid: from $1.99/month for unlimited
Platforms: Linux, macOS, Windows, OpenWrt
Download: github.com/nextdns/nextdns
Bottom line: Install this if you already use NextDNS and want to confirm your setup is doing what it promised.
6. Cloudflare 1.1.1.1 GUI, best one-click swap
1.1.1.1 with WARP installs a native app on Windows and macOS that switches system DNS to Cloudflare’s DoH endpoint with no manual resolv.conf or Windows network-adapter fiddling. The app also shows latency to their edge, so you get a rough sanity check on whether the swap helped.
Where it falls short: No comparative benchmark against other resolvers. Assumes you already decided Cloudflare is the right pick.
Pricing:
- Free
- Paid: WARP+ from $4.99/month adds prioritized routing
Platforms: Windows, macOS, iOS, Android, Linux
Download: 1.1.1.1
Bottom line: The right pick when GRC has already told you Cloudflare is fastest and you want the switch to be one click.
7. DNS Jumper, best for Windows tinkerers
DNS Jumper is a portable Windows app that lets you cycle through preset resolvers, benchmark them, and apply a change without restarting the network. Handy on machines you touch once every few months, since the app is a single .exe with no installer.
Where it falls short: Windows only. The bundled benchmark is less detailed than GRC’s.
Pricing:
- Free
- Paid: none
Platforms: Windows
Download: sordum.org/7952/dns-jumper-v2-3
Bottom line: Portable, drops on a USB stick. Useful when helping a family member fix “slow internet” over a weekend visit.
8. dnstop, best for diagnosing chatter
dnstop shows every DNS query leaving your machine grouped by source and destination. Useful when a benchmark says the resolver is fine, but browsing still feels slow: often the culprit is one background app hammering DNS with a thousand queries a second.
Where it falls short: Reads packets, so it needs elevated privileges. On Windows use it through WSL or reach for the Sysinternals equivalent.
Pricing:
- Free
- Paid: none
Platforms: Linux, macOS, BSD
Download: github.com/measurement-factory/dnstop
Bottom line: Reach for it when the benchmark is clean but “internet still feels slow” persists.
How to pick the right one
Pick GRC DNS Benchmark on Windows if you want one definitive answer in ten minutes.
Pick NameBench on macOS or Linux for the same job.
Pick DNSPerf’s public dashboard as the pre-flight check that narrows the shortlist.
Pick dnsperf CLI when you need percentile numbers or you are benchmarking your own resolver.
Pick NextDNS CLI if you already use NextDNS and want to confirm it is delivering.
Pick 1.1.1.1 GUI when the benchmark told you Cloudflare wins and you want the switch to be painless.
Pick DNS Jumper for a portable Windows fix on someone else’s machine.
Pick dnstop when the benchmark looks fine but something on the machine is still generating too many queries.
FAQ
Why do speed tests miss DNS? Speed tests measure throughput to a nearby server after DNS resolves. The resolution itself happens in milliseconds, so a slow resolver looks like a fast connection with slow pages loading.
What is a good DNS response time? Under 30 ms for uncached queries is excellent. 30-80 ms is typical for a public resolver. Over 150 ms is worth switching away from.
Are Cloudflare and Google DNS actually faster than my ISP’s? Usually yes for uncached queries. ISPs cache heavily so a page you visit twice a day feels the same, but new domains often resolve faster on Cloudflare or Quad9.
Should I use DoH or plain DNS? DoH adds a small latency cost (5-15 ms) and hides queries from the local network. If the tradeoff is worth it depends on your threat model. On a home network the answer is usually yes.
Does switching DNS help with buffering on streaming services? Sometimes. Streaming platforms use CDNs whose “closest edge” is picked based on where your DNS resolver appears to be. A resolver in the wrong city can send you to a worse edge.
