I have Roku Express ( 3900X)
I have been powering it from the supplied Switching Adapter, the printing on which shows it has an output of 5V 1.0A.
It would save me a three pin socket & make life easier if I could power it from one of the USB sockets on my wall socket outlets. They show they are 5V 2.1A. The product data sheet is here: https://d2cq9zndfvtoz7.cloudfront.net/VPSS580WH.pdf
I'm not an expert in electricity so could anyone let me know if this is safe to do please?
It's absolutely safe. You can use any 5V source that can supply at least 1A. 2.1A is even better. The 2.1A refers to the most that it can supply. A device will only take what it needs.
You already have an extension strip with a USB socket, which will be fine, even better if surge protected.
Otherwise I would recommend one of the USB power supplies that also allows a 13a UK plug to be plugged in, so you aren't wasting a 13a wall socket. Available from supermarkets or online for about £10, status and masterplug brands.
That's perfect - just what I needed to know. Thanks & merry Christmas.
Thanks for the advice - I think @renojim has given me just what I needed to know.
Merry Christmas!