The BBC is to screen Doctor Who’s Christmas special in 4K resolution and high dynamic range (HDR) colour via iPlayer.
When the programme is broadcast, viewers will be prompted to switch to the higher quality streamed version by pressing the red button.
US video platforms including Disney+, Netflix, Apple TV+ and Amazon Prime Video commonly offer content in this format.
But it is more rare on the BBC and Sky.
To take advantage of the facility, households will need a compatible TV and a relatively fast internet connection.
Ultra-High Definition (UHD) – the other name given to 4K – delivers four times as many pixels as regular 1080p high-definition (HD) video.
The benefits are that images can appear sharper and more detailed, although this is not always apparent if the screen is not large enough or viewers are sitting too far away.
For many people it is HDR that delivers the most notable difference.
Pictures typically appear to be more vivid and colourful.
It takes advantage of the fact screens can go brighter and/or darker than they used to be able to, providing a greater dynamic range.
As a result, the shadows of an image can be made less murky while the highlights – including sparks from special effects – can have more impact.
The BBC first publicly tested 4K HDR on iPlayer in 2016 when it offered four minutes from its Planet Earth II series.
It has subsequently offered a limited range of full-length programmes including Dynasties; His Dark Materials; and Dracula, as well as sport including Wimbledon and Fifa World Cup 2018 matches.
But despite pioneering related technologies – such as developing the hybrid-log gamma format used to stream live action simultaneously in both HDR and normal TV – it has been resistant to deploy it widely.
This had led to odd situations such as Peaky Blinders being offered in HDR on the UK’s Netflix service but only Standard Dynamic Range (SDR) on iPlayer.
The BBC is, however, also providing further shows in 4K HDR over the coming days including:
A spokesman for the corporation added that there would be further content in the new year.
The announcement comes a month after Sky announced it was boosting its library of 4K HDR movies for Christmas, including adding all the Harry Potter films in the format.
However, at present it is limiting this to its Sky Q satellite service and not its Now TV streaming platform, which is still broadcast in 1080p.