Screen resolution vs Browser resolution

I'm a bit of an amateur when it comes to all this, but having recently started posting photos online again I noticed a distinct lack of sharpness in my browser (this forum) vs what I was seeing after re-sizing in lightroom.

After further inspection, it seems whenever I post images online, they are blown up or enlarged, but with the same resolution obviously. This leads to a much less sharper version appearing....I can make them the same by changing my browser magnification to 50%, but that then makes the font almost unreadably small. I'm guessing this also means all other users are seeing the blown up image, rather than what I see in lightroom (or anything that's just on my mac, and not in the browser).

Is there any way around this? I'm guessing it's something to do with different native resolutions, but i'm not very tech savvy and really am not sure how to make sense of it.

Thanks for any help!

What are the pixel dimensions of the photos you are uploading?

I have heard that many sites will botch up the sharpness of photos if they have to resize them.
So maybe look for the recommended photo sizes (pixel dimensions) for a particular site, upload a photo of that size and see if that makes a difference.

Changing the browser magnification is NOT the solution.

You say you are using a Mac, does it have a Retina type screen by any chance? With the retina screens they do some clever tricks with most programs to make them readable. Effectively they double up the pixels to reduce the effective resolution. They would need to do this with images in web browsers too, otherwise they would break the page layout. If you then reduce the zoom to 50% in the browser, that will mean that the pixel binning is effectively removed, and you get a true 100% view of the image.

When you are using LR though, although the textual parts of the application also undergo pixel binning to make the text readable, the actual images are not, so a 1:1 LR view will show the image at a true 1:1 on screen.

I have a friend who went out and got a 27" iMac as he thought he needed that to be able to post some (unedited) videos to youtube and update his website. He finds that the 2500 odd pixel resolution of the screen to produce text etc that is hard for him to see. To "fix" that he runs the display at a lower non native resolution. The screen looks pretty bad set up like that.It kind of put me off the idea of a iMac until I had realised what he had done, and I now reset the screen when I have to do work on it for him. He and his wife bought the thing because they fell for the Apple hype, they ended up spending nearly £1500 on a system they won't even run at optimum settings, to do a job that could have been done on a system costing £300.

Alan

Wow, thank you Alan, I think you have absolutely pinpointed my problem and explained it very well. I do indeed have the retina display.