page speed – Lighthouse API – Total Blocking Time

I am using the Lighthouse API to get page load metrics for my site. I’m getting some huge outliers for my Total Blocking Time metrics.

Since the results are a little different with each request, I’m taking the average of 5, so I’m making 5 requests per URL I’m testing.

All other metrics differ slightly with each request, except for TBT. Usually it ranges from 0 to about 80, but then sometimes it comes back appx 800. See screenshot below, where TBT is third column of data, and the rows are 5 requests for one URL. The last row is the average.

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