I check my url because facebook don't use the image that I set on og:image
My image is: 639x649px 486kb But fb use this picture: 300x443px 97kb
The warning said:
og:image should be larger: Provided og:image is not big enough. Please use an image that's at least 200x200 and preferably 1500x1500. (Maximum image size is 5MB.) Image 'url from image, size: 300x443px 97kb' will be used instead.
But when I try to create an image 1500x1500px, upload to server, refresh, and check again the link on top, the results are the same.
My experience with Facebook made me doubt that computers are deterministic machines :)
Sometimes it will accept image of any size (between 200 and 1500px), sometimes complain that image is too small (og:image should be larger) even if image is squared and bigger than minimum size (e.g. 400x400px). I had situations where the same link showed all 3 og:images in linter and in FB status field, then suddenly 2 weeks later stopped working and started showing only one image while trying to share it in FB status field (linter still showed all 3 images), and vice versa. Sometimes FB seems to have problems with different domains (e.g. page is on www.example.com and og:image on www.picdumpexamplesite.com), sometimes it doesn't mind...
IMHO it's heavily broken, and the best you can do is:
- make images squared, rounded to "hundreds", e.g. size 300x300px
- host them on the same server (same domain name)
- use jpg
- avoid any "strange" chars in filename (I use only letters and numbers)
- pray that something of the above works :)