# What is a DNS cache?

Understand stored DNS answers, TTLs and why a changed domain record may not appear immediately in every browser or network.

Website: https://zenshield.com/glossary/dns-cache

Canonical URL: https://zenshield.com/glossary/dns-cache

Page reviewed: 2026-09-12

A DNS cache stores answers to earlier name lookups so they can be reused. Caches can exist in the browser, operating system and recursive resolver.

## Why an old answer can remain

DNS records have a time-to-live value, commonly called TTL. A resolver can reuse a cached answer during its remaining lifetime instead of asking for the record again each time.

For example, if a website operator moves a service to a new address, one resolver may already have the new answer while another still holds an earlier one. Two users can see different results without either user having mistyped the domain.

## What clearing a cache changes

Clearing your device’s cache removes its locally stored answers. It does not edit the domain’s authoritative records or force every upstream resolver to forget its own cache.

That distinction matters when troubleshooting. Repeatedly clearing a laptop cache will not fix a wrong record published by the domain owner.

## A useful comparison

Ask [the DNS lookup tool](https://zenshield.com/tools/dns-lookup) for the domain and record type. Note the answer and TTL from that public resolver. Compare them with the domain owner’s intended configuration if you manage the domain.

If the issue is confined to Windows using an old answer, try [flushing Windows DNS](https://zenshield.com/help/flush-dns-windows) once. If the domain fails on several networks, investigate its authoritative configuration or contact the site owner.

A DNS cache is separate from browser history, page cache and account cookies. Clear the item relevant to the problem instead of deleting unrelated browsing data.

## Sources
- https://www.rfc-editor.org/rfc/rfc1034