Why DNS Not Updating 24 Hours

Why DNS Changes Take More Than 24 Hours

When you update a DNS record — changing an A record to point to a new server, adding an MX record for email, or updating CNAME entries — the change does not take effect instantly for all users worldwide. DNS is a distributed system with multiple layers of caching. Each layer holds records for a duration controlled by the TTL (Time to Live) value you set on your records. Until each cached copy expires, users at that resolver continue to see the old value.

A TTL of 86400 seconds (24 hours) means every resolver that has cached your record can continue serving the old value for up to 24 hours after you make the change. This is the most common reason DNS appears stuck: the TTL was not lowered before the change was made. The solution is to lower TTL to 300 seconds (5 minutes) at least 48 hours before any planned DNS change, then make the change. With a 5-minute TTL, propagation completes for most users within 5-15 minutes.

The Three Layers of DNS Caching

DNS propagation is slow because records are cached at multiple independent levels, each with its own expiry timeline:

• Your authoritative nameserver: The source of truth. Changes take effect here immediately when you save them in your DNS dashboard.
• Recursive resolvers (ISP and public DNS): These servers cache records for the duration of the TTL. Google DNS (8.8.8.8), Cloudflare (1.1.1.1), and your ISP's resolver all cache independently.
• Your local machine and browser: Operating systems and browsers cache DNS lookups in addition to the resolver-level cache. Even after the resolver cache expires, your machine may still serve a local cached copy.

If you see the new record from one location but not another, different caches are at different stages of expiry. This is normal and temporary — it resolves once all caches expire and re-query the authoritative nameserver.

What to Do When DNS Is Still Not Updated After 24 Hours

If a full day has passed and DNS still has not updated, the issue is probably not caching — something else is wrong. Work through this checklist:

1. Verify the record is actually saved: Log in to your DNS provider and confirm the new record is present with the correct value and TTL. A common mistake is forgetting to click "Save" after editing.
2. Check which nameservers are active: Run dig NS yourdomain.com to see which nameservers are authoritative. If the NS records point to a different provider than where you made the change, your edit went to the wrong place.
3. Check for conflicting records: If an old record for the same hostname exists at the same provider, the conflict may prevent the new record from being served. Delete the old record before adding the new one.
4. Use the propagation checker: The DNS propagation checker queries 50+ global servers and shows exactly which ones have the new value and which have the old one — or no record at all.

Nameserver Changes vs Record Changes

Nameserver changes (moving from one DNS provider to another) take significantly longer than individual record changes. When you change nameservers, the parent TLD zone must be updated, and that update must propagate through the global DNS hierarchy. This process genuinely takes 24-48 hours. Individual record changes within the same DNS zone propagate much faster — typically within the TTL of the record being changed.

If you recently changed nameservers and are still seeing old records, allow the full 48-hour window. Use the propagation checker to monitor NS record propagation separately from the records within your zone.

For a step-by-step walkthrough of checking propagation, see How to Check DNS Propagation. If propagation appears complete but your site still isn't loading, see Subdomain Not Working and the DNS Not Propagating Fix Guide.