Short answer: upload 2560 × 1440 px (max 6 MB) and keep all text inside the central 1546 × 423 px.
What each device shows
| Device | Visible area (px) |
|---|---|
| TV | 2560 × 1440 (everything) |
| Desktop | about 2560 × 423 |
| Tablet | about 1855 × 423 |
| Mobile | 1546 × 423 (safe area) |
Tips
- Channel name, tagline and schedule go in the safe area.
- Fill the rest with color or a background image that can be cropped.
- Use the ⇹ and ⇕ buttons in the editor to centre elements exactly.