Here’s what happens if you change the URL of a story that’s going viral on Facebook

On Sunday afternoon reported that a Republican Party headquarters in North Carolina was firebombed the night before.

Kaleida showed that their story was moving really fast on Facebook earning over 40 engagements per minute. The article had 18,000 engagements and climbing and then, suddenly, it fell off a cliff.

Data from

Engagements hit zero at 5:45 am GMT (12:45 am Eastern Time) and instead of climbing at 40 engagements per minute and reaching for 20k or more in total, the article started from zero again and earned about 2 or 3 per minute for the next several hours.

Now it has about 5,000 engagements in total.

What happened?

At some point during this article’s life Fox News changed the URL. When it launched Sunday afternoon (8:36pm GMT/3:35 Eastern) the URL was:

The URL probably changed at 12:09 am Eastern Time and became the following:

Fox News changed the day in the URL, presumably for enhanced positioning in Google News.

Interestingly, Facebook knows the original URL as you can see from their debugger tools. But it appears that when the ‘canonical’ URL was changed they must have zero’d the engagement count. It’s also interesting to note that Facebook still recognized the old URL for about 30 to 40 minutes before changing the way they were dealing with it.

Why did the momentum crash so suddenly? Just because the URL changed shouldn’t mean people would share it any less, right?

We have to assume that it was moving quickly because the story was hot and people were sharing it on Facebook a lot. But when it suddenly registered zero engagements the Facebook algorithm must have reprioritized other stories in front of it.

The new URL meant that Facebook thought it was a new article with no engagement instead of the highly active article that was flying across their network only moments before.

All those shares coming from within the world of Facebook, particularly URLs being viewed via the mobile browser or as instant articles, disappeared behind the news feed algorithm.

The lesson here is to be careful about changing URLs, particularly the <link rel=”canonical”> tag in your HTML. It seems Facebook will consider it a new page and rescan for engagement counts on the new page. All your engagements will be lost.

This is a case where what works in search may actually do damage in social.

Originally published at on October 17, 2016.