During the most recent Google English Google SEO office-hours (from September 10, 2021), Search Advocate John Mueller read and responded to a question:
“We embed YouTube videos on our website. However, these significantly slow down our page loading times according to Page Speed Insights. Embedded mp4 videos do not slow down the page loading time at all; therefore, for SEO, is it better to embed mp4 videos?”
Should You Switch Just for SEO Reasons?
John’s response was, “…at least from…the normal ranking and search crawling indexing ranking point of view, I don’t think it makes sense to…switch to a different video format just because of SEO reasons.”
So, there’s the short answer. But, there’s more:
“If you’re looking at speed, obviously there are different ways of embedding videos, and that can be different formats of videos that can be different ways of embedding the existing videos.”
John went on: “and in particular, when it comes to YouTube, there are ways to embed videos that use a kind of lazy loading where you show, for example, a placeholder image and someone clicks on it, then it activates the video itself, and if you set that up, then I think you should be able to set these pages up so that they actually load pretty quickly.”
But really…who wants to go through all that? Google’s the one that’s been telling everyone to have fast load times/page speeds, yet embedding a video from one of their own properties slows download times.
Well, at least part of John’s response is hopeful for the future: “I also know the YouTube team is working on improving the default embed as well, so maybe over time, that will improve.”
But, until then…?
“…but at least until then, I would look into different ways to just embed the same videos, and if you decide to host these videos yourselves and just to put the .mp4 files directly on your site, that’s also fine, that’s perfectly acceptable–up to you. When it comes to videos, the thing I might watch out for is that Google is able to recognize the video metadata for these things…”
If You Do Choose to Use .mp4 Videos On Your Site…
“…and with normal Youtube embeds, usually we can pull that out fairly well. If you’re embedding these yourself, or using a kind of a custom player to embed the videos, then I would double check that you have the structured data for videos appropriately on your pages as well.”
So, if you have embedded YouTube videos and are concerned about SEO, apparently, it’s not a big deal. If you embed .mp4 videos, be sure to have the appropriate structured data.