Wifi or Wired Connection for Videoconferencing?

Short answer, always choose a wired Internet connection if you have the option when you are the HOST of a web conference.  Avoid wireless connections at work, wherever possible, they are often overloaded.  Your home WiFi may be fine but its a good idea to test it first.  One way you can do this is to do an Internet speed test.  The closer you are to the WiFi access point the better your results will be.  Here are two samples from my home:

Wired Connection

Wireless Connection

So if you are the host, and if you are hosting from home, do a few speed tests to make sure you have a good connection.  And kick people off Netflix during your talk so you have plenty of bandwidth to play with.

Still reading and want to know more?  Here's a quick explanation on networking.  When you transmit data it gets broken up into little tiny chunks called packets.  Each packet has a header and a payload.  The best analogy is the mail.  Your computer is the mailbox and the packets are the mail.  The mail has an envelope (the header) containing all the stuff we need to know to get to the letter from sender to the receiver.  The letter inside (the payload) is what we actually care about.  We open the letter and toss the envelope away.

Now our deal Aunt Mildred is worried about us getting bored from the Covid-19 pandemic and thought we could use some reading material.  Aunt Mildred is also a bit of a joker so she sent us Stephen King's "The Stand" to us one page at a time all in separate letters.  Now we need to transport all those letters here.  Hopefully Aunt Mildred is using a wired connection (Ethernet) because it is inherently more stable.  I'm quickly running out of analogies so I will just jump to the tech end.  The network patch cable that you see plugged into your computer uses a series of twisted pairs of copper.  Here is what they look like on the inside:

The twisting is important it helps to reduce electromagnetic induction between wires.  Assuming a 256Mbps connection errors should be less than 0.001% losses, or 1 packet in 100,000.  So chances are you got that entire novel in one go in the right order without any missing pages.  Awesome! 

WiFi on the other hand is an inherently lossy medium as it relies on radio waves on top of already being slower than a wifi connection.  Errors get introduced because of walls, interference from electric motors, and other other wireless access points.  It seems every device out there has a WiFi antenna built into it.  Error rates can be high as 10% and you would never know it as an end user as there is so much error checking and requests for re-sending missing or corrupted packets.  The software on your computer is programmed to handle these errors and may take steps to resolve the problem.  This could be lowering the quality of the feed or dropping bits of data that just got there too late which is why you may see black screens or have the audio cut out.

Now when you are a participant, not a huge deal.  Your bad connection only affects you.  But as the host it is a big deal as a bad connection means that you are dropping out for everyone signed into your talk.  So use a wired connection whenever you can and barring that do whatever you can to improve WiFi including physically moving closer to the access point and cancelling Internet heavy services like online gaming and Netflix until your session is completed.