When I run a Lighthouse performance audit on our site, one of the 'Opportunities' it flags is to 'Reduce the impact of third-party code'.

It lists all the third-party code used by our site, however at the top is an entry for 'Research Online', with a size of 689 KB and a Main thread blocking time of 1,040 ms. Interestingly it is the only entry with out its name linked anywhere.

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Who or what is 'Research Online'?

I'm running a production build of the site in an incognito tab, so it isn't anything development-related or something related to a Chrome extension. I've checked network requests and there are none that are to URLs I'm not expecting.

  • One way to figure out would be to go into the network inspector tab for that page, and look through all the scripts that are loaded in order to find it. Jun 4, 2020 at 17:53
  • @MaximillianLaumeister Thanks, but that was the first thing I tried. There are no requests to anything unexpected. Jun 4, 2020 at 18:23
  • I believe you've actually spotted a bug in Google Chrome due one of its upstream packages. This time, it's actually the web browser's fault. Jun 4, 2020 at 18:46

1 Answer 1


Your website is on a .org.uk domain or loads scripts from one, right? How did I guess?

This "Research Online" mis-labeling is due to a bug in the third-party-web dataset, fixed in commit af5bfdb line 7786/7781 in January, and merged into Google Chrome's codebase last month.

Chrome uses this dataset to identify and name third party scripts, and the dataset had mistakenly listed scripts from all .org.uk domains, including the first-party domain, as "Research Online".

I assume that the fix will make its way to the stable version of Chrome in time.

More details in the Google Chrome issue here.

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