The four main delay components
Propagation is travel time; serialization is time to place bits on a link; processing is work done by devices; queueing is time waiting behind other traffic.
PHYSICS EXPLAINER
Is 0 ms Ping Possible? Why Tests Show Zero
Exactly zero elapsed time is not possible across a real network. A displayed 0 ms can be a rounded sub-millisecond response, limited timer resolution or an unstarted test. Check the destination, precision and completed samples before interpreting it.
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What a displayed 0 ms can mean
For example, 0.4 ms rounded to the nearest whole millisecond becomes 0 ms. The elapsed time is still 0.4 ms. Some tools truncate instead of rounding; inspect their precision rather than assuming every zero has the same cause.
| Reading | Possible explanation | What to check |
|---|---|---|
| 0 ms after a completed test | A response was rounded or the timer could not resolve the duration. | Check decimal precision and the timing method. |
| 0.2 ms to localhost | The operating system responded locally. | This does not test your router or internet path. |
| 1 ms to your router | The local network path is short. | Compare with an external destination separately. |
| 0 ms before starting | The interface may show a placeholder. | Check completed and valid samples. |
How to verify a zero reading
- Confirm the test finished. Missing or failed samples are unavailable, not zero.
- Identify the responding endpoint. Localhost, your router and an external server are different paths.
- Repeat to the same destination and record method, precision and successful sample count.
- Compare idle and busy conditions separately. A low minimum does not describe typical delay or stability.
ICMP ping, HTTP request timing and WebSocket echo timing include different work. Browser timers can also have reduced precision for privacy. A displayed zero is not evidence of instant packet delivery.
References: IETF round-trip delay metric and MDN browser timer precision.
Measure response timing to a real destinationCompare the distance-based propagation floor. If games or calls lag despite low idle timing, check timing under load.
Why tools sometimes display 0 ms
A rounded display may show 0 ms for a sub-millisecond local response. That is a measurement and formatting result, not literally zero elapsed time.
QUESTIONS
Common questions
Can a gaming connection have 0 ping?
A real round trip to a remote game server takes time. A displayed zero may be rounded, a placeholder or an application-specific indicator. More Mbps cannot remove the propagation time to that server.
Can localhost ping be 0 ms?
It may be displayed as 0 ms after rounding, although computation and scheduling still take time.
What is the lowest possible internet ping?
It depends on physical path length, medium and equipment; there is no single global minimum.
Does 0 ms in a speed test prove instant internet?
No. Check whether the number is a placeholder, a rounded reading or a response from a nearby endpoint. A completed result must identify its measurement method and destination.
Why does my speed test show 0 ms ping?
A displayed zero can reflect rounding, limited timer precision, a nearby endpoint or a placeholder before completed samples. For example, 0.4 ms rounds to 0 ms at whole-millisecond precision; it is not instantaneous.
Is zero ping possible in online games?
A real exchange with a remote game server takes positive time. The game can display 0 because of rounding or its timing method, but that does not remove propagation and processing delay.
Can ping be lower than 1 ms?
Yes, to a nearby local endpoint under suitable conditions. Sub-millisecond response timing remains positive and does not establish the ping to a distant game server.
Formula and limitations
Values use transparent approximations described in the article.
Reference constants: NIST speed of light in vacuum. Fiber propagation uses a disclosed engineering approximation of 204,000 km/s; actual group velocity varies with the fiber.