If your NextJS App Router app is throwing this error:

UND_ERR_REQ_CONTENT_LENGTH_MISMATCH 

Then it’s likely that you are using fetch which is the standard option for making HTTP requests. There was an open issue for using Fetch within NextJS since NextJS wraps the default fetch with their own implementation. To help isolate this issue, we replaced fetch with axios, and it resolved the errors!

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janac

Most of my writing is about software. I enjoy summarizing and analyzing books and self-help videos. I am senior software consultant at LazerTechnologies.com.