Resolution: SD, HD, Full HD and 4K
Resolution is the number of pixels in the picture. Standard definition (SD) is the lowest, followed by HD, Full HD and 4K (Ultra HD), which has four times the pixels of Full HD. Higher resolution looks sharper, especially on large screens, but needs more data.
Frame rate
Frame rate is how many pictures are shown each second. Higher frame rates make fast movement — such as sport — look smoother. Many broadcasts use 50 or 60 frames per second for live events, while films are usually shown at 24.
HDR
HDR (high dynamic range) adds brighter highlights, deeper shadows and richer colour. You only see it when the programme is made in HDR and your TV and streaming device both support it.
Why quality varies between channels
- Each channel is broadcast at its own resolution and frame rate — not every channel is available in 4K.
- Some channels have several versions, such as SD, HD and 4K, listed separately.
- Fast-moving programmes need more data, so they show limits sooner than a studio programme.
What your internet connection needs
Higher resolution, higher frame rate and HDR all need more bandwidth. The connection that matters is the one at your screen, at the time you watch — and it is shared with everything else using your internet at that moment. Rather than relying on a single number, test your speed on the device you watch on, in the evening, and compare HD and 4K versions of the same channel.
How to tell if your connection is the limit
- Step 1: Play a 4K channel and its HD version, if both are available.
- Step 2: If HD plays smoothly but 4K pauses, your connection or Wi-Fi is the limit.
- Step 3: If both pause, try the network fixes in our home network guide.
What limits picture quality
| Part | What to check |
|---|---|
| The channel | Whether it is broadcast in HD or 4K — not every channel is |
| Streaming device | Whether it can output 4K and HDR |
| TV | Its resolution, HDR support and HDMI input settings |
| HDMI cable and any soundbar | Whether they pass through 4K and HDR |
| Internet connection | Your speed on that device, at the time you watch |
Your equipment matters too
To see 4K or HDR, the TV, the streaming device, the HDMI cable and any soundbar or receiver in between all need to support it. Check your TV's settings to make sure the HDMI input is set to its enhanced or full-bandwidth mode if it has one.
In short
Picture quality depends on the channel, your equipment and your connection together. Check each one in turn, and use the channel directory to see the channel lists available in your region.
Want to check a particular channel before you order? Ask our team on WhatsApp.
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