176x176 but we noticed that it still trims the pictures and that the best setting for a profile picture is 170x170. The minimal actual dimension of a profile picture is 200x200.851x315 pixels with the actual minimal width of 399 pixels wide.Facebook uses meta-tags to render previews of webpages. The following tool can be used to check what a page will look like when posted in a textbox on Dacebook.
Facebook's Lint Object Debugger: https://developers.facebook.com/tools/debug
Anything that can be searched in facebook and has a public picture can also be referenced anywhere. For example, if you look for Wizardry and Steamworks:
https://www.facebook.com/wizardry.steamworks
You can capture the mini icon in a text chat by typing:
[[wizardry.steamworks]]
Similarly, if a page, group or image with a profile icon has a facebook id, for example:
https://www.facebook.com/photo.php?fbid=274265749347502&set=a.274265732680837.60003.274263839347693&type=1&theater
The code after the fbid parameter can be used in the same way and will render a small icon of that picture:
[[274265749347502]]
Every asset on Facebook is referenced with a given ID. Whenver you want to refer to some asset, the name is usually secondary since two assets can have the same name but different IDs.
Go to the following URL:
https://graph.facebook.com/username
where username can be the name of a page or your personal username. The result be similar to the following:
{
"id": "1456183517929484",
"about": "Virtual Islands for Better Education is a community of virtual worlds users and educators.",
...
and shows the ID.
Whenever you upload photos to an album on Facebook, after tagging the photos, adding a date and so on, you will get a blue Post button. If you want the new photos to not show up on your timeline, simply do not press the Post button. Instead, just close the window as if you have changed your mind.
You will most likely get a popup saying that you have not completed posting the images (technically, the browser is telling you that some parts of the form have not been submitted) and ignore the popup. If you go back to check your album, the photos will be there however they will not show up in the news feed.