It is roughly 164 KB.
This is my standard web image format.
This is the same photograph, though post-processed at a later date, so the cropping and tones are not identical.
This one is again saved from Affinity 3, this time in .WEBP in its high-quality lossy format.
This one is only 104 KB, so already a decent bandwidth saving.
Here we have another .WEBP image, also exported from Affinity 3, this time in its lossy low-quality format.
It's definitely softer than the high-quality image, but on the other hand it's only 22 KB, which is a pretty massive saving.
I've been resistant to using .WEBP as my default image file format for web display, but I think I'll have to change my mind.
There are a couple of other options coming up: .AVIF and JPEG-XL, both of which are reputed to give benefits over .WEBP, but neither of those formats is in common usage just yet.
I can create JPEG-XL from Affinity, though with a pretty restricted range of options, but I can't create AVIF at all, and even if I could there's a good chance that they wouldn't display in a browser just yet. Soon though.