How to Fix Slow Internet Problems After macOS Sierra‎ Update

How to Fix Slow Internet Problems After macOS Sierra‎ Update

It’s hard to stay away from upgrading your Mac computer to the latest version of macOS Sierra. There are so many cool features and a redesigned interface that every Mac users should experience.

Just like most people, I decided to give it a try and my Macbook Air upgraded to the new version without any problem.

While other blogs have reported a handful of challenges with macOS Sierra, I only saw one, and it has to do with the internet speed on my Mac. After getting the upgrade, I tried to browse the web using Google Chrome, but the internet speed was very slow. General fixes like rebooting the modem didn’t do the trick.

It was evident that my Wi-Fi was slower than usual and updating to macOS Sierra definitely caused this problem. Even some static pages take forever to load.


How to Fix Slow Wi-Fi after macOS Sierra upgrade

After doing some research, I found a solution to the slowness of my Wi-Fi. If this happens to you in macOS Sierra, try the following.

  1. Turn off your Wi-Fi completely
  2. Create a new folder on your desktop and name it
  3. Open your Finder (the smiley face icon on the dock) and press Command + Shift + G. All three keys at the same time
  4. This will pull up Go To Folder. From there type in: /Library/Preferences/SystemConfiguration/
  5. Look for the following files:,,, NetworkInterfaces.plist, preferences.plist
  6. Copy and paste them to the folder you created in Step 2
  7. Then delete those .plist from the SystemConfiguration


One more step before you’re done. Restart your Mac computer. Once it’s rebooted, connect to your Wi-Fi again. My internet connection went back smoothly. I can feel it’s much faster than before. If you continue to encounter slow Wi-Fi connection, visit a nearby Apple Store for further assistant.

Disable Automatic Download in macOS Sierra

Did you know that Apple will automatically download and install macOS Sierra on your Mac computer? Well, now you know, and it will be executed starting today (Oct. 3). Luckily, users are allowed to turn this feature off.


Here are a few reasons why:

  • Background downloading can effect overall internet speed
  • It’s at least a few GBs in storage space

To disable macOS Sierra automatic download, go to System Preferences > App Store. Uncheck the option for “Download newly available updates in the background.”

From now on, if you want to check for new updates or get the update just go to the App Store and perform it manually.

HSTS/SSL Certificate Error

So here’s what happened earlier.

I opened up my MacBook Air and tried to take advantage of the free Wi-Fi at one of my local Starbucks. After that, I launched Google Chrome and boom, an error message popup.

Your connection is not private or secure…This site uses HTTP Strict Transport Security (HSTS)…normally uses encryption (SSL) to protect your information.

Although this particular problem do not deal with your Wi-Fi being slow it’s possible for some users to get the same issue after upgrading to macOS Sierra.

How to Fix SSL certificate problem

  1. Click on the Wi-Fi icon on your Mac’s menu bar
  2. Select Open Network Preferences..
  3. Click Advanced and then choose the current network that you’re connecting to
  4. Select the Subtract sign next to the addition sign and click Ok
  5. Stay on the same Network Preferences… page and click on Wi-Fi on the left side
  6. And click the subtract sign at the bottom > Apply
  7. Now, click the addition sign and choose Wi-Fi under Interface and Service name
  8. Click Apply to save all your changes

Re-connect to the Wi-Fi network that you were having trouble with earlier. This will help you fix the SSL error in Google Chrome.


I don’t know if there is any better solution than the method I instructed above. If you found any, please let us know using the comment section below.

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Bin Nguyen
Bin Nguyen
Passionate tech writer, I been a geek all my life. Love to write and explore new tech