Website DNS TTL controls how long resolvers cache your DNS answers, in seconds. It does not make pages, images, or server responses load faster.
DNS means Domain Name System. TTL means Time to Live. When someone visits your site, their resolver stores the answer for the TTL period before asking again.
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What TTL Controls
TTL sets the cache lifetime for each DNS record. A short TTL tells resolvers to ask for a fresh answer sooner. A long TTL lets them reuse the stored answer longer. A TTL of 300 spreads a change in about five minutes for new lookups.
A TTL of 86400 lets resolvers reuse the answer for about one day. Short values suit planned moves, while longer values suit stable records. Each record can carry its own TTL. A domain often has separate TTLs for the root, www, mail, and verification records. Change only the records you plan to move.
What TTL Does Not Speed Up
TTL does not change hosting speed, page weight, page caching, or code execution. After DNS resolves, the browser connects to the server and TTL rests. Later page views reuse connections and stored files, not DNS. A lower TTL does not make a site feel snappier.
It can add DNS lookups because resolvers expire answers sooner. Visitors may see slightly more lookup delay, not less. Faster loads come from other work. Reduce image weight, shorten server response time, limit heavy scripts, and use page caching. Those steps affect every visit, while TTL affects only how often resolvers ask where the site lives.
How to Choose a TTL Value
Match TTL to how often the record changes. Stable sites often use 3600 to 86400 seconds. Records you expect to change soon often use 300 or 600. Very low values such as 60 help during active failover testing.
They also raise query load and depend on resolvers honoring them. Some resolvers enforce minimum cache times, so treat a tiny TTL as a request rather than a promise. For a WordPress or Drupal move, separate web traffic from mail traffic. Lower the TTL for the web records before migration. Keep mail records stable unless the mail destination is also moving.
How to Time a DNS Change Safely
Lower the TTL at least one old-TTL period before the change. If the old TTL is 86400, lower it one full day early. Wait out that period, then change the address.
Keep the old server running until its logs show little remaining traffic. Some visitors will arrive through cached answers after the switch. Restore a longer TTL once the new destination proves stable.
- Check the current TTL for each record you will change.
- Lower those records to 300 or 600.
- Wait one full old-TTL period.
- Change the address to the new server.
- Confirm the new site, forms, checkout, and tracking work.
