Speed per 4K stream
- Netflix: 15 Mbps or higher for 4K Ultra HD.
- YouTube: 20 Mbps recommended sustained speed for 4K.
The word that matters is sustained. A 4K stream needs that speed continuously for as long as you watch. A connection that tests at 30 Mbps once, then dips when someone else starts a download, can still drop to HD mid-show.
Planning for several 4K TVs
| 4K streams at once | Minimum for video alone | Comfortable with other use |
|---|---|---|
| 1 | 15–20 Mbps | 50 Mbps |
| 2 | 30–40 Mbps | 100 Mbps |
| 3 | 45–60 Mbps | 150–200 Mbps |
| 4 | 60–80 Mbps | 200–300 Mbps |
The “comfortable” column is our guidance, leaving room for calls, gaming, phones and background updates.
How much data 4K uses
At 15 Mbps, an hour of 4K uses about 6.75 GB. At 25 Mbps it is about 11 GB per hour. Streaming services adjust quality on the fly, so real usage varies. If your home internet or mobile plan has a data cap, a few evenings of 4K can add up quickly.
What else 4K needs besides speed
Fixing 4K buffering
- Test next to the TV. Run the test on a phone or laptop beside the TV to see what reaches it.
- Use a cable or 5 GHz WiFi for the TV or streaming device if you can.
- Pause big downloads while watching, or schedule console updates for overnight.
- Restart the streaming device and check for app updates.
- If wired speeds are above 25 Mbps and 4K still buffers in the evening, it may be congestion. See how to fix slow internet.