Bandwidth

Internet Speed Needed for HD and 4K Streaming

Bandwidth needs depend on stream bitrate, codec, device and simultaneous connections. The figures below are illustrative planning estimates, not measured requirements for every TREX stream or a guarantee of buffer-free playback.

Copy reviewed 17 October 2026. Check playback on your own device and connection.

Illustrative bandwidth estimates

Quality	Estimated per-stream range	Example connection headroom
SD	1–2 Mbps	5 Mbps
HD 720p	3–5 Mbps	10 Mbps
Full HD 1080p	5–8 Mbps	15 Mbps
4K (HEVC)	15–25 Mbps	35 Mbps

Add the bandwidth used by each simultaneous stream and leave headroom for other household activity. Actual bitrates may fall outside these example ranges.

Why the speed test says you are fine

A speed test measures a short burst to a nearby server under ideal conditions. Streaming is a long, steady pull from a specific host. The three things that break streaming while leaving speed tests looking healthy are:

Evening contention

Your local exchange saturates at peak time. Test at the moment it buffers, not the next morning.

Wi-Fi, not the line

The bottleneck is between the router and the device, which no speed test run on a phone next to the router will show.

Packet loss

Packet loss can interrupt playback even when a speed test shows adequate throughput.

How to test properly

Test from the device that buffers
Not from your phone, and not next to the router.
Test while it is buffering
The result five hours later tells you nothing about the moment it failed.
Run it three times
A single result can be an outlier. The lowest of three is the number that matters.
Compare wired and wireless
If Ethernet is stable and Wi-Fi is not, stop looking at your ISP.

More bandwidth may help if your connection cannot sustain the stream bitrate or other devices are competing for capacity. It will not necessarily fix Wi-Fi interference, packet loss, device limitations or a source outage.