Why DNS Changes Aren't Instant
When you update a DNS record, your authoritative nameserver has the new value immediately. But your domain's old records are cached in resolvers all over the world. Those resolvers won't query your nameserver again until the cached record's TTL expires.
If your A record had a TTL of 86400 (24 hours) and someone queried it 1 hour ago, their resolver won't ask again for another 23 hours. During that time, they get the old IP even though you've already updated the record.
The DNS Lookup Chain
A DNS lookup travels through several layers, each with its own cache:
- Your browser — caches DNS results for a short time
- Your OS — the operating system DNS cache
- Your ISP's resolver — caches based on the record's TTL
- Public resolvers (8.8.8.8, 1.1.1.1) — each with their own cache
- Your authoritative nameserver — the source of truth
When you make a DNS change, propagation means waiting for all these caches to expire and re-fetch the new record.
How to Speed Up DNS Propagation
The most effective technique: lower TTL before making changes. If you lower your record's TTL to 300 seconds (5 minutes) and wait for the old TTL to expire, propagation after your actual change takes at most 5 minutes.
The full process:
- Lower TTL to 300 on the record you're changing
- Wait for one full cycle of the old TTL (e.g., 24 hours if old TTL was 86400)
- Make your DNS change
- Verify propagation — should complete within 5 minutes
- Raise TTL back to 3600+ once confirmed
Plan it properly: The DNS TTL Migration Planner calculates the exact timing for each phase based on your current TTL and planned change date.
Why Different People See Different Results
Two people checking your domain at the same time might see different IP addresses. Person A's ISP resolver hasn't refreshed yet (still caching the old record). Person B uses 1.1.1.1 which already has the new value. This is normal — it's not a sign something is wrong, just that propagation is in progress.
Check propagation status: The DNS Propagation Checker queries 20+ global resolvers simultaneously so you can see exactly where your change has and hasn't updated.
With default TTLs (1–24 hours), propagation takes anywhere from minutes to 48 hours depending on what resolvers have cached. If you lower TTL to 300 before making the change, propagation takes under 5 minutes.
Different devices use different resolvers with different cache states. A device using 1.1.1.1 may have refreshed already while another using your ISP's resolver hasn't. Wait for all TTLs to expire.
Cloudflare's DNS (1.1.1.1) typically picks up changes faster than ISP resolvers. But the authoritative side — how fast Cloudflare's nameservers see your change — depends on your DNS provider.