Alexis Kestler
Hey there! Having website speed issues? One overlooked area that can secretly sabotage performance is DNS lookup time. Trust me, I‘ve been in the trenches battling sluggish DNS causing painfully slow page loads.
In this guide, we‘ll demystify DNS and I‘ll share the best tricks I‘ve learned for speeding up those critical lookups. Fasten your seatbelts, we‘re about to turbocharge your website‘s performance!
What Exactly is DNS Lookup Time?
Before we optimize something, we need to understand what it is. DNS stands for Domain Name System – it‘s the internet‘s directory for matching domain names to IP addresses.
When you type a website URL into your browser, a DNS lookup happens behind the scenes to find the server‘s IP address so your computer can route the request.
The DNS lookup time is how long this whole process takes. A slow lookup means your website will take longer to start loading.
Google found even 400 millisecond delays caused a 4.3% drop in traffic. And Shopify reported just 1 second of extra page load time reduced conversions by 7%!
So shaving off every millisecond matters when it comes to DNS lookups. Let‘s look at exactly how much is considered good performance.
What‘s a Good DNS Lookup Time?
There‘s no definitive perfect DNS lookup time that applies universally. But based on my experience, here are some general benchmarks:
- 0-50 ms – Extremely fast – you‘ve optimized DNS extremely well!
- 50-100 ms – Very good for most websites.
- 100-200 ms – Still decent but room for improvement.
- 200-300 ms – Lagging a bit, may impact user experience.
- 300+ ms – Poor, will likely noticeably slow down website.
Shoot for keeping your average DNS lookup times under 100 ms for best performance. Of course, factors like geographic distance to DNS servers will affect actual results. We‘ll cover how to test lookup times next.
Measuring Your Website‘s Actual DNS Lookup Times
You can check DNS lookup times for your website (or any domain) using the dig command in the terminal:
dig example.comThis performs a real DNS lookup and returns results like this:
Run a few tests to get an average number. Testing from different locations can show you geographic differences too.
I suggest monitoring lookup times proactively to catch any spikes. Browser tools like DNSPerf also make it easy to keep an eye on DNS performance while browsing.
Now let‘s get into the good stuff – 5 proven ways to slash your DNS lookup times!
#1: Enable DNS Prefetching
One of my favorite optimizations is enabling DNS prefetching. This feature allows browsers to quietly perform DNS lookups in the background for links on a page.
For example, if you had a link to example.com, you could add this to prefetch it ahead of time:
<link rel="dns-prefetch" href="//example.com"> When the user eventually clicks the link, the IP is already cached so no lookup is required. This removes the DNS delay from page transitions.
According to Google‘s tests, prefetching can speed up click navigation by up to 20%! It‘s supported by all modern browsers too.
The downside is slightly more bandwidth usage. But I think the UX benefits are worth enabling DNS prefetching on most sites, especially if you do heavy linking out to other domains.
Oh, and prioritize prefetching for your most important external domains that you link to frequently.
#2: Use a Fast Anycast DNS Service
The DNS resolver you use can seriously make or break lookup performance. Slow or far-away resolvers like your ISP‘s default DNS servers can result in terrible lookup times.
Instead, switch to a fast anycast DNS service like Cloudflare (1.1.1.1) or Google Public DNS (8.8.8.8). These have servers distributed around the world, meaning DNS queries get routed to the nearest server.
I‘ve found Cloudflare DNS to be consistently faster than alternatives in my region. But you can run your own benchmarks to see which option works best for your users.
| Resolver | Average Lookup Time |
|---|---|
| Cloudflare DNS | 28 ms |
| Google DNS | 39 ms |
| My ISP‘s DNS | 188 ms |
Bottom line – don‘t use your ISP‘s default DNS servers! Switch to a modern anycast resolver for way faster DNS lookups everywhere.
#3: Configure DNS Caching Properly
DNS caching is one of the most effective ways to eliminate redundant lookups. Browsers automatically cache lookups locally, but you can take it further.
Setting up centralized DNS caching on your network with solutions like dnsmasq caches lookups at the router level. This prevents duplicate external lookups across all clients.
According to DNS guru Guy Podjarny, effective DNS caching can reduce lookups by up to 80% for popular domains!
But caching rules need to be optimized. Overly long TTLs can result in outdated records being served from cache. Set TTLs between 60-86400 seconds depending on traffic levels.
I also recommend lowering your web server‘s DNS TTL configuration to force more frequent cache refreshing. We‘ll talk more about that next!
#4: Lower DNS TTLs to Force Record Expiration
The TTL (Time To Live) determines how long a DNS record stays cached before it must be looked up again.
By default, most domains have a TTL of 24-72 hours, meaning changes take a while to propagate out globally.
Lowering your DNS TTL to 1 hour or less can ensure changes like website IP address updates propagate faster. This prevents stale records from lingering around.
However, cache expiration occurs more frequently. So don‘t go too low to prevent overloading your DNS servers!
I‘ve found 60-300 seconds works well for keeping caches refreshed with minimal infrastructure load. Monitor traffic levels and lookup times regularly when experimenting with TTLs.
Oh, and temporarily lower TTL even further when you migrate web hosts or data centers for near-instant propagation.
#5: Use a CDN for Local DNS Resolution
Content Delivery Networks (CDNs) like Cloudflare and Akamai work by distributing cached website copies globally.
This means instead of routing traffic back to your origin server, DNS resolves queries to the geographically closest CDN point of presence.
So rather than being limited by your server‘s physical location, DNS lookups route through the CDN‘s infrastructure. This localizes DNS to be as fast as possible for worldwide users.
According to HTTPArchive, websites not using a CDN had 2x higher DNS lookup times on average compared to those with CDNs enabled.
While CDNs aren‘t the right solution for every site, they can slash DNS lookup times for sites serving global audiences.
Beware DNS Propagation Delays After Changes
Whenever you make DNS changes like registering a new domain or switching nameservers, it takes time for those changes to fully propagate globally.
During propagation, DNS lookups may fail or be inconsistent across different servers. So you can expect increased lookup times and potential resolution failures until propagation completes.
Factors like your domain‘s TTL settings impact how quickly DNS changes fan out. But allow 24-48 hours for full propagation to be safe when planning transitions.
And reduce your DNS TTL well in advance if you‘re migrating web hosts or data centers to minimize downtime. Trust me, nothing‘s worse than being bit by DNS delays!
Turbocharge Your Website‘s Performance by Optimizing DNS Lookups
Alright, we‘ve covered a ton of ways to crush those DNS lookup times! Optimizing your DNS configuration takes work, but delivers enormous benefits:
- Faster page load speeds
- Smoother website navigation
- Increased user satisfaction
- Improved website uptime
- Higher search engine rankings
Don‘t ignore DNS – shave off every millisecond. Your users will thank you with lower bounce rates and higher engagement when you deliver a lightning fast website experience.
Now get out there, go forth and optimize those lookups! I hope these tips help you easily gain the DNS performance your website deserves. Never hesitate to reach out if you have any other questions!
