Facebook has added high resolution photos and full screen photo viewing. From today, the photo viewer will show the highest resolution image available, rather than offering a download link for higher-res images (up to 2048 pixels along each edge). An option to expand the photo to fullscreen has also been added. The changes also include adding a simplified version of the sRGB color profile to each image, increasing its chances of displaying color correctly.

Press Release:

Improving the Photos Experience

Today we’re announcing a few enhancements to our photo viewer, including high-resolution photos and fullscreen viewing.

High-Resolution Photos

Now the photo viewer will automatically display photos in the highest resolution possible. On a large display, this can be up to 4 times bigger than before.

Fullscreen View

Starting today, you can expand the photo viewer to take up your entire computer screen.
If you’re using the latest version of Firefox or Chrome, click the arrows at the top-right corner of a photo to expand to fullscreen.

To read about more photo updates, visit Facebook Engineering.

To learn about the tools you can use to make your photos look better, visit the Help Center.