Clearing the Cache. Have you ever edited a blog post, like the title for example, and then notice that when you test the Facebook share button the data popping up is old? After any link is shared, Facebook caches the data. So if you didn’t know this already, you need to clear Facebook’s cache. So how do you do this? And where do you go?
Facebook has a debugger. You can find it here. If you’re not logged into Facebook you will need to do so. In the space provided, add the URL for the blog post, then click the blue button “Debug”.
On this next screen click on “Show existing scrape information”, then click “Fetch new scrape information”.
You’re done! It’s that simple. If the post hasn’t been shared on Facebook yet, you don’t even need to worry about this. But if it has, you would need to clear the cache. While you’re at it, you might be interested in checking out what’s on those debug pages. It will show you what the Facebook post will look like among other things.
September 20, 2015 Update on Facebook Image Thumbnails
I’d like to add that recently I had a problem with a share not posting as previewed after clicking on the Facebook share button. Instead, the picture used for the Facebook image thumbnail that posted on Facebook was all blown up and looked nothing at all as expected. I ran the debugger, and the preview of what it would look like on Facebook was not how it looked in reality! How frustrating!!
I have since learned that for the Facebook image thumbnail, an image’s aspect ratio of height and width cannot be greater than 3. That just means that the width of the image cannot be 3 times greater than its height and vice versa.
Also keep in mind that the image used must be at least 200 x 200 pixels in size.
For a Facebook image thumbnail, WordPress looks for a featured image. If there is none, then they look inside the post. If there is an image inside the post, it will try and use that. If there is none, WordPress will look elsewhere. I’ve had them use the butterfly image located in the righthand column of my blog. And yet again, another image tried was my header image. The butterfly image works great, but trying the header image proved troublesome. My guess is because it is way too wide. So my word of advice? Test the Facebook button after you publish each post to be sure it posts correctly. The debugger comes in really handy for testing purposes. Good luck.