In general, it’s best to go to each player and watch a programme in the best video quality possible. However, you might want to watch in SD (standard definition) rather than HD (high definition) to reduce data usage or buffering. BBC iPlayer offers this option; the ITV Hub and All 4 will attempt to adjust to the quality of your internet connection*.
*A minimum broadband speed of 2Mbps is required to watch catch up and on demand services – this will count towards any monthly broadband data allowance. Only selected channels provide 7-day catch up.