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DNS does not change your game ping

A DNS server answers one question before your game connects: which address belongs to a name. The round trip your game measures starts after that answer, on a path the DNS server is not part of.

Updated

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What DNS does

Your device knows a game service by its name; the internet delivers packets by address. A DNS server translates the one into the other. The DNS standard, RFC 1034, has resolvers keep each answer for a time the name's owner sets, the time to live, so your device does not ask again for every packet.

1. Once, before the match: name to addressDNS serverYour deviceGame server2. Every game packet, the whole match:straight to the address, no DNS on the pathYour ping is the round trip of step 2
One lookup before the match, then every game packet goes straight to the server address. The ping is the round trip on that second path.

Why your ping does not include it

Once the game has the server's address, its packets travel from your device through your router and your provider to that address and back. The DNS server sits off to the side of that path, so a faster DNS server has no way to shorten it. Distance, routing and your home network decide the round trip.

Our test works the same way. Its first request to each test point covers the DNS lookup and the opening of the connection, and the test throws that request away. Only the 10 requests after it count, so a change of DNS server cannot move a figure in your result either.

Where DNS does play a part

  • Connecting. A DNS server that fails or answers slowly can delay a login or a server list, or stop a connection from opening. That happens before the match, not during it.
  • Old answers. Flushing the DNS cache makes your device ask again. It fixes a stored answer that went stale; it does not shorten a round trip.
  • Publisher advice. Riot suggests a public DNS server for the stability and reliability of a League of Legends connection. The page does not say it lowers in-game latency, and Riot's main troubleshooting guide names physical distance to its servers as the largest factor in latency.

What to change instead

Run the test and let the verdict pick the fix. Each one points at a part of the path DNS never touches.

The verdict of the ping test and the change that fits it
VerdictWhat to change
Close and stableNothing at home. If the game still lags, check its own ping display and status page.
Close but unstableThe home network: a cable, the 5 GHz band, background downloads, router QoS.
Far from the serversThe route from your provider to the region: when the route is the problem.
Cross regionThe region you play on, if your game, friends and account allow a nearer one. If not, see VPN or game booster.

Questions about DNS and ping

Does a public DNS server lower ping?
Not the round trip of a match. The DNS server answers before the game connects; after that, game packets go straight to the server address. Run the test before and after the change: the medians move no more than they do between any two runs.
Why do some guides say to flush DNS?
Flushing clears the answers your device has stored, so it asks again. That helps when a stored answer points somewhere that no longer works, which shows as a failed connection, not as a high ping.
Can DNS cause lag spikes in a match?
A lookup happens when a connection opens, not for every game packet. Spikes during a match come from the home network or the route. The spread in the test shows which: high on every region points at home, high on one region at the route to it.

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