Does Prime Video support 4K? How many devices can stream at once?

Yes — 4K UHD and HDR content is included with the membership at no extra charge (unlike Netflix, where 4K requires the Premium plan). There's no hard cap on signed-in devices, but the account supports up to 3 simultaneous streams.

What it takes to actually get 4K

All three conditions must be met:

1. The title supports it — look for the "UHD" badge on the detail page; many titles also offer HDR10+ or Dolby Vision.
2. The device supports it — a 4K TV, Fire TV 4K, Apple TV 4K, PS5, and similar. Web browsers generally top out at 1080p or even 720p due to DRM, so use a TV or streaming-box app for real 4K.
3. Enough bandwidth — a stable 15 Mbps or more for 4K; about 5 Mbps for 1080p.

If playback starts soft, give the adaptive stream a minute or two to ramp up, or set Streaming quality to Best in the player or app settings.

Streams and device limits

• The whole account can run at most 3 streams at once. Seats are planned around this, so collisions are rare in normal use.
• The same title can play on at most 2 devices simultaneously.
• If you see "Too many devices are streaming," the account is momentarily at its 3-stream cap — wait a few minutes. Don't change account settings or sign out other devices over it.

Offline downloads

The mobile apps support downloading for offline viewing. Downloads carry limits (typically watch within 30 days of downloading, and within 48 hours once started); reconnecting and refreshing renews expired items.