Google’s John Mueller answered whether Chrome-based spam traffic could negatively impact core web vitals scores. John Mueller isn’t on the Chrome or web platform team, so he had to pause a moment to think about that a second before answering.
One of the implications, an underlying question, is if it’s possible to launch a negative SEO attack focused on poisoning Core Web Vitals and thereby affect a known ranking factor.
Chrome User Experience Report
The Core Web Vitals scores that become ranking factors are derived from real users on Chrome browsers.
The browsing information contains the actual web page download data from real devices visiting actual web pages.
This data is what Google calls “field data” and it’s what is used to calculate the Core Web Vitals score that is subsequently used as ranking factors.
Google uses the browsing data from Chrome browser users to create the Chrome User Experience report.
Google’s developer pages describe the process like this:
“The Chrome User Experience Report is powered by real user measurement of key user experience metrics across the public web, aggregated from users who have opted-in to syncing their browsing history, have not set up a Sync passphrase, and have usage statistic reporting enabled.”
Real users on Chrome can have an impact on Core Web Vitals scores.
So the person asking the question had a legitimate concern.
The person asking the question framed it as “spam traffic” that is “using Chrome as a browser.”
The person is unclear as to whether these were actual people using Chrome browsers on slow connections or if these were bots.
John Mueller didn’t ask for clarification, unfortunately.
Bots Spoofing Chrome
There are many kinds of bots that aren’t Chrome, they simply imitate Chrome (this is called spoofing the user agent of Chrome).
For example, a Python-based web scraper can spoof Chrome to trick a website that it’s just a normal site visitor.
Those kinds of bots won’t affect a website’s Web Vitals Scores because they are not Chrome, they’re just scripts.
Headless Chrome Bots
There are other kinds of bots that are based on the real Chrome browser that are called Headless Chrome.
Headless Chrome is the Chrome browser but without user interface of Chrome, which is why it’s called headless.
It’s unlikely the Headless Chrome browser can send back Core Web Vitals information either, since Headless Chrome is designed for testing purposes.
Spam Traffic with Real People Using Chrome
The nightmare scenario is spammers sending actual people on a slow Internet connection to visit a site while using Chrome browsers that are opted in to the Page Experience Report.
How would Google filter out real people using Chrome with bad intentions from negatively impacting Core Web Vitals?
Can Chrome-based Spam Traffic Influence Core Web Vitals?
The person asking the question called it “spam traffic” and didn’t clarify if that meant human spammers or bots.
This is the question asked:
“In the recent week we’ve seen a huge increase in direct spam traffic on some of our websites, coming from all over the world using Chrome as a browser.
This spam traffic is very slow. We’re a bit concerned about Chrome metrics that are used to evaluate page speed and rankings.
Is Google aware of this? Is there something that we can do?”
Google Answers if Chrome Spam Traffic Affects Core Web Vitals
John Mueller answered:
“Uhm… So… I don’t know …we see lots of weird spam traffic on the web over time and we have a fairly good understanding of that.
And the way that, as I understand it, with regards to the core web vitals, what we use… in the Chrome User Experience Report data, there are certain requirements that we watch out for and we almost certainly filter out for the usual spam traffic that’s also out there as well.
From that point of view I wouldn’t expect this to cause any problems.
If you’re really worried about it and you have some data that you can send me then I’m happy to pass that on to the Chrome team so that they can take a look.
But I would not assume that this would cause any problems.
We see all kinds of weird spam traffic all the time and our systems are pretty tuned to avoid that kind of thing.”
Can Google Catch Chrome-based Spammers?
It seems fairly clear that a Headless Chrome bot would not affect core web vitals scores. I couldn’t find documentation that says that explicitly but it just feels like the way it should be. Would be nice for some clarification from Google though.
John Mueller is confident that the Chrome User Experience Report filters out the “usual spam traffic.”
But he also offered to take information back to the Chrome team to review.
How do you feel about it?
Does Chrome-based Spam Traffic Impact Core Web Vitals?
Watch John Mueller answer the question at the 30 minute mark: