Fixed? macOS Monterey Slow Upload Speeds? It Might Not Be your Imagination! [update #4]

macOS Monterey (12.0.1) may have a networking bug. This article details the Monterey slow upload speeds bug that slows your upload speeds dramatically.

Written By
Michael Sheehan
Published On
December 10, 2021

I always recommend upgrading to the latest and greatest Operating System whenever possible. From new features to enhanced security to bug fixes, an OS upgrade is typically a smart choice…until it isn’t. I recently upgraded two MacBook Pros I use (one for work and one for home) to macOS Monterey (12.0.1). I love many of the new features. But I started noticing something strange after a while – macOS Monterey slow upload speeds. Initially, I didn’t realize that the problem was isolated to Monterey. But, after some research and my own testing and troubleshooting, I realized I wasn’t the only one experiencing this AND that it probably was a “Monterey slow upload speed” bug.

As more of us get used to working (or studying) from home, having fast broadband Internet access is crucial. It’s especially important when having to stream video (classes or calls). But an important factor to remember is, it’s not just your download speed but also your upload speed that should be fast. When you are on a conference call, you are uploading your video stream.

At the beginning of the pandemic and the shelter-at-home initiative, I did an article and video talking about the importance of upload speeds, particularly when it comes to video conferencing. And this is part of the reason why I continue to pay for the top fiber tier from my provider (1Gbps download and 1Gbps upload).

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Update #1 (12/13/21): macOS 12.1 does NOT resolve the issue described in this article.

Update #2 (12/16/21): Added a section with more information in this article discussing additional testing.

Update #3 (1/27/22): Latest Apple Developer beta (12.3) may have resolved.

Update #4 (3/25/22): macOS 12.3 released – seems to have resolved on my machines.

My macOS Monterey slow upload speeds troubleshooting journey

Well, recently, I suddenly started noticing that my Webex calls were not as good as they used to be, and I was getting warnings from the software that there were network issues. I thought it was general network congestion until I ran some network speed tests. And then I noticed something very odd.

The speed tests showed fast download speeds but not so fast upload speeds (907 down & 187 up).

Slow Monterey upload speeds - HightTechDad

I started to think that perhaps I was having a network issue within my house. My laptop was hard-wired into the Ethernet network. I was not using WiFi to ensure I had the fastest network connection possible.

I decided to do another speed test using my non-work MacBook Pro. And, while it too was hard-wired (both using USB-C hubs with Ethernet ports), my upload speeds were quite slow as well.

So, I started thinking I should rewire my home network.

But then I tested my wife’s Windows desktop. Hers is hard-wired as well. And she had blazing-fast download AND upload speeds. Hmmm…

Again, I was back to something being wrong in my home office. I restarted computers, replugged in switches, unplugged non-essential devices, and changed some Ethernet cables in my office. Nothing helped.

Then I restarted my Nest WiFi Router and did a test. Same slow upload speed issue. I restarted my fiber modem. No change. I prioritized one of my MacBook Pros using the Nest WiFi interface. Any change was barely perceptible.

And, I ran a speed test on my Nest WiFi Router. It showed things being pretty darn quick (748 down & 802 up).

Nest Wifi Router Speed Test - HighTechDad

I ran a similar test on my ISP Fiber Modem. Same result – fast upload and download speeds (999 down and 915 up).

Fiber Modem upload & download speed test - HighTechDad

So, the modem was fast, and the main network router was fast. Something else was going on.

I started thinking about my wife’s PC working just fine, so I plugged a Windows laptop into the same USB-C hub (with the Ethernet port) that I was having issues with on my MBP. Interestingly, it had fast upload speeds (852 down & 802 up).

Windows PC speed test - HighTechDad

I then decided I probably didn’t have to rewire my under-the-house Ethernet.

So, through the process of elimination, I found a common denominator. Upload speeds were fast on Windows but slow on Macs.

But was it all Macs? I had tested on a 2019 MacBook Pro and a 2021 MacBook Pro M1. Then I decided to try my daughter’s MacBook Pro (a 2020). First, I did a WiFi test. Both upload and download speeds were quick (for WiFi) and equal. Then I tried plugging her MBP into my USB-C hub with the networking. She had fast upload and download speeds (840 down & 723 up).

Fast download & upload speeds on Big Sur - Monterey Slow Upload speeds - HighTechDad

I was on to something. Only my macOS Monterey Macs running 12.0.1 were affected by what I’m now calling the Monterey Slow Upload Speed bug.

Long story short, I did some more testing. I plugged my Monterey MBP into my fiber modem router directly and still had slow upload speeds.

And I did some quick online research and found a few threads on Apple Support Forums and Reddit talking about these slow speeds (but everyone had different theories from it being a hardware issue to a problem with their ISP).

With all of this testing and research completed, I decided to reach out to Apple Support on Twitter.

And, I will cut to the chase here. I had a great Twitter exchange with the awesome Apple Support folks who walked me through various things to test and try. I have outlined below a few things you can also try as they may help with other network slowdown issues.

They couldn’t resolve the issue, so they escalated it to a more senior Apple support person who I worked with to provide all sorts of diagnostics compiled and sent over for the Apple networking engineers to review.

But…the bottom line…my macOS Monterey slow upload speeds bug still exists as of this writing!

I’m sure this issue will be resolved shortly (and by the time you read this, it might already be fixed). BUT, if you are encountering these same issues, contact Apple Support! That is what they recommend. The more people who report this, the faster it will become resolved!

Update #1 (12/13/21) – macOS 12.1 does NOT resolve

I eagerly awaited macOS 12.1 with the hopes of it resolving the issue. I updated on my two MBPs and the issue remains.

Update #2 (12/16/21) – further troubleshooting & more results

I had another followup call with Apple Support. We worked through some additional questions and I submitted more diagnostics (e.g., Wireless Diagnostics even though I am NOT connecting via WiFi – only using Ethernet). One of the recommendations was to try a completely different network which is what I did. My neighbor also has fiber internet with 1Gbps upload and download speeds.

macOS Monterey slow upload speed

TL;DR – same issues persist on this other network AND we confirmed with other MBPs running Monterey (note: second Big Sur MBP does NOT show the slow upload speeds on this network).

To summarize all of the things I have tested:

  • Windows machines connected via Ethernet do NOT show slow upload
  • macOS Big Sur connected via Ethernet do NOT show slow upload
  • macOS Monterey (12.0.1 & 12.1) connected via Ethernet DO show slow upload on TWO distinct networks
  • Tested in Safe Mode w/ Ethernet – SLOW upload speeds
  • Tested with a temporary administrator w/ Ethernet – SLOW upload speeds
  • Tested with a new network location w/ Ethernet – SLOW upload speeds
  • Tested with 3 MBPs running Monterey w/ Ethernet – SLOW upload speeds
  • Tested with 2 Macs running Big Sur w/ Ethernet – FAST upload speeds
  • Tested with 2 Windows machines w/ Ethernet – FAST upload speeds

Note: I have tested using WiFi as well on all devices. Monterey Macs do show a perceived slowdown but it is not as evident as with Ethernet.

Another reason why this might not be as apparent “in the real world” is because many broadband providers have plans that have FAST download speeds but SLOWER upload speeds by default. So, any “perceived” upload slowdown may be harder to detect due to the nature of upload speeds being slower anyway.

I have NOT installed a developer or public beta nor have I rolled back to Big Sur.

Please leave a comment if you are experiencing this issue AND/OR open a support ticket with Apple.

Update #3 (1/27/22) – A light at the end of the “tunnel”?

First, I would like to thank all of the commenters on the thread. It is great getting additional reports “from the field” and being able to test other environments and scenarios! Thank you!

I haven’t posted an update as I didn’t feel like there was “good news.” There are a lot of things that need to be tested with each release. And the comments below outlined some great ideas and things to try (e.g., VPN, removing profiles, creating locations, etc.). I did try many of those things but still was having issues.

I did notice, as I continued to test, that sometimes the “poorer” results were browser-specific and that typically it was Safari that was performing less well. I did test the Safari Technology Preview as well but still ran into issues.

I was hoping that macOS 12.2 would fix things. I installed the Developer beta but unfortunately, even after the final version was released, I still had the issue.

I did also notice that how you test your speeds (and I was focusing on the UPLOAD speeds) did create some variance. I tried the Google speed test as well as the Ookla website and standalone app. Bottom line, speeds were inconsistent across test and browser types. I even tried the new Terminal app command of “networkquality -s” (the “-s” flag makes one test run after the other instead of simultaneously). Still inconsistent (but slow upload speed results).

Today, a new Developer beta (macOS 12.3 – build 21E5196i) came out and I rushed to install it. I’m an optimistic guy by nature, and I definitely am encouraged by the results. Here is a nice collage of various results so you be the judge!

HighTechDad speed test results macOS 12.3 (Dev beta)

Remember, I am NOT using WiFi at all. These are all USB-C to Ethernet connections. My provider plan is for 1Gbps UP and DOWN.

If you have access to the Developer Beta and are encountering these similar issues, please leave a comment below letting us know your results! My fingers are crossed!

Update #4 (3/25/22) – better performance for me, what about you?

In my previous update, I mentioned that the Developer Beta seemed to have resolved my issues but I was waiting to install the final production version of 12.3 on my work MBP (which doesn’t allow for betas). I have now been running macOS 12.3 on both computers and my upload speeds are much closer to what I was expecting (pre-Monterey levels).

I still have been receiving some comments on this article of others continuing to have issues. I would love to get more feedback. So, leave a comment if your upload AND download speeds have improved or not after installing macOS 12.3.

Have networking issues like the Monterey slow upload speed bug? Try these possible fixes

I don’t like describing issues without offering some possible solution. (See my How-To and Fix-It content.) So, if you are encountering networking issues like what I described here with macOS Monterey having very slow upload speeds, or just slow networking in general, here are a few tips or ideas you can try to potentially fix. Some of these are Mac-specific, while others are just general best practices.

  • Restart your computer – this is the first thing I tell anyone having computer issues to do. Just do it!
  • Reboot your WiFi router – routers are like computers, they need to be rebooted occasionally as well. I would do this every couple of months regardless of whether you are having issues or not.
  • Reboot your cable/DSL/fiber modem – for the exact same reason as the previous two points, restart your modem if you can.
  • Use wired (Ethernet) connection instead of WiFi – wired connections will ALWAYS be faster than WiFi. If you can, go wired!
  • Change your Ethernet cable – your cable may have gone bad, or the plug is not seated correctly – it’s always good to get a new (or different) cable to test with.
  • Boot in Safe Mode to test (Mac) – booting your Mac in Safe Mode allows you to eliminate 3rd parter applications and processes from interfering with the core OS. Here’s how to do it on a Mac. (You can do this on a PC as well.)
  • Review Apple’s “Recommended settings for Wi-Fi routers and access points” – most of these settings are generic and not Mac-specific.
  • Reinstall the macOS (ugh) – this is a second to last resort, but sometimes it is a good thing to do to “refresh” your macOS install.
  • Roll back to a previous macOS version (double ugh – but I believe that will fix it) – I didn’t try this. I really didn’t want to go backwards. But, I’m almost 100% convinced that if you go back to Big Sur, this slow upload speed bug will go away.

Those are just a few quick ideas on how you might be able to resolve some networking and other issues. Unfortunately, it didn’t help with my Monterey slow upload speed bug. I’m probably going to just wait it out (I even decided against installing the Developer Beta or the Public Beta).

Fast & Slow upload and download speeds - macOS Monterey Slow Upload Speeds - HighTechDad

But I want to know! Are YOU experiencing slow upload speeds on macOS Monterey? What version are you on? 12.0.0 or 12.0.1? Are you having this issue with a different macOS version? PLEASE leave a comment!

HTD says: Every new version of macOS becomes increasingly complicated with new or refined features, bug fixes, and security updates. But sometimes, in the billions of lines of code, a critical bug slips through – this Monterey slow upload speeds bug is one of them!

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