Firefox desktop · Research guidance. Instructions are based on publisher guidance; a UK IPTV account was not tested on this platform.
Confirm the text in the page first
Start the video in its ordinary webpage and enable the supplied captions or subtitles there. Make sure the desired text actually appears before moving the picture into another window. If the page has no suitable track, picture-in-picture cannot be assumed to invent an official transcript or another language option.
Use the documented video control
Mozilla describes a picture-in-picture toggle on eligible videos and other entry points, including the address-bar action on suitable single-video pages. Enter the floating window only after the in-page caption state is established. Keep the original tab open so its full programme and language controls remain available.
Check actual website support
Mozilla documents caption handoff for supported websites and compatible contexts; it does not promise every custom player behaves identically. If the text disappears only in the floating window, compare that result with the working in-page state. That is a more useful observation than reporting that subtitles are universally absent from the programme.
Arrange a readable presentation
Resize and position the floating window for the text and video you need to follow. Do not keep shrinking it merely to clear another application if captions become unreadable. The useful result is an accessible viewing arrangement, not simply confirmation that the browser can open a second window.
Return to the working mode when necessary
If this combination does not carry the captions you need, continue in the original page and record the browser, site and specific transition. Avoid installing an unrelated extension or changing account settings just to reproduce a feature another website happens to support. The procedure checks browser presentation; it does not test an IPTV service’s entitlement.
Questions, answered
Should captions be enabled before entering the floating window?
Mozilla’s documented handoff starts with captions enabled in the in-page player.
Does picture-in-picture guarantee captions on every site?
No. Support depends on the actual website/player context.