Q: Wifi is incredibly slow on OS X El Capitan

Is it the same even though you're close to your router? I had the same problem when I was connected to my 5Ghz band and being a bit far from the router. But when I started using a repeater/extender to get a stronger signal closer to me, I never got the problem again. Like I mentioned in my earlier post, there must be something wrong with the OS that makes the download speed slower when the wifi signal is not the strongest.

* I never had the problem when connected to 2.4Ghz band.

** My repeater extends my 5Ghz to 5Ghz band.

Even after going all the way up to Mac OS 10.11.2 El Capitan, I spent a half day trouble shooting wifi connectivity issue. I finally powered up my old laptop and realized the wifi network was up and running well just not with Mac OS 10.11.2 El Capitan. I found an excellent youtube video on how to fix the issue. Worked for me. video at youtube  https://www.youtube.com/watch?v=-eCxgPiTb5s

Actually, after some success it turned out that my wi-fi problem was not fixed by a tech.  It did return.

However, after updating to the latest OS X release, 10.11.2, the problem went away.  There were reports of a wi-fi fix and it seems that was true.  Happy with my 12" MacBook now. 

I was struggling with slow wifi since El Capitan update (honestly, it can be that this was the case already before that update! Cannot really say for sure!). I was extremely happy to see that last OSx update was including fix for Wifi issue finally, unfortunately that was NOT the case with my mac!

It seems that now I FINALLY found solution and wanted to share it with you all, hopefully it can help someone else.

First, some details of my setup:

I use MacBook Pro (Retina, 13-inch, Early 2015) with El Capitan 10.11.2

Wifi router is Buffalo Air station 125, 2.4GHz, i use AES encryption with PKI.

I have docking station and two external displays connected via thunderbolt adapters plus magic mouse.

Symptoms:

Wifi was very very very slow, like 0,7Mbps (mainly I used speedtest.net for testing). Using iPhone with same router showed correct speeds, so issue seem to be only in my mac. In some point I noticed that if I take my mac out from docking station and use it with out external displays, connection speed will be back to normal.

What I have tried?

I browsed a lot information via google and it seems that there is lot of same kind of issues with solutions (deleting settings, manually configuring DNS & MTU settings etc...), none of those fixes where helpful for me, absolutely no difference at all.

If found one discussion where someone have had some help by disabling bluetooth. For me this was not fixing anything, but also noticed that bluetooth frequency can be around 2,4Ghz, same as my wifi router uses. This lead me to try out something what finally was solution.

Solution

Simply, I logged into my wifi router setup and changed channel from Auto (it showed channel 11 at that time) to 1. After reboot my Wifi router, speed was back to normal!  

The recent update which allegedly included a wifi fix did nothing for me, in fact the problem seemed to get worse. My internet will become unusable every 5-10 minutes and I need to turn wifi off and on (on the mac) and it instantly re-connects.

I have tried a few fixes thus far (DNS and proxy settings, resetting PRAM, deleting the saved wifi network and re-adding it, and of course a million reboots of the router and machine at first, before I realized this was a problem with the **** OS) .

I couldn't access my router settings via wifi so I will try jsaa29882's suggestion later after I bring home an ethernet cable.

I just bought the machine in September... I've always been a PC user and this was my first Mac purchase. Ha. Feels like the joke's on me now that I see that some people had this problem throughout Yosemite's life span? Ridiculous. I didn't even realize such glaringly defective products were possible from such a giant?!

Hi everyone – just wanna share. I’ve had the same issue/problem for the longest time with my El Capitan. I had to use my Windows laptop for Wifi connectivity. However, the recent update really fixed this issue. I found it really fast. Hopefully this is true to everyone.

Cheers,
Giusseppe

Spent a lot of time yesterday with an Apple Tech Supervisor ... and in a 3-way call with my internet provider, Comcast.  The solution was Comcast updating the firmware in the modem/router they provide.  Rebooting one's router does not mean updating firmware.  In my case, the router was no longer fully compatible with El Capitan.  Those who own their own routers may have to chase down a firmware upgrade.  This is not my guess, but the opinion of the Apple tech ... and whether it involved a huge firmware update or simply a reconfiguration, the ROUTER was my problem.  Smarter guys than me on this forum can fine tune my findings.

I had the problem with Yosemite, tried some of the various fixes, nothing worked. Apple tech help said I needed to use Capitan. Upgraded. Problem worse than ever. Using new Air is incredibly frustrating, have to turn off/on wifi to print to wireless printer, to send email, etc. Does Apple care about this problem?

johnettpdx wrote:

 

I had the problem with Yosemite, tried some of the various fixes, nothing worked. Apple tech help said I needed to use Capitan. Upgraded. Problem worse than ever. Using new Air is incredibly frustrating, have to turn off/on wifi to print to wireless printer, to send email, etc. Does Apple care about this problem?

Changing the wireless chanel, updating router firmware... all to no avail?

Did you do a clean install or just updated from Yosemite?

I'm the author of several books, have written for major publications, and I am wondering if I should be required to have a degree in computer science in order to use my Airbook? I don't know much of what you are speaking of here, and I'm not sure I should be required to repair/fix a machine that should be working. In the 1980's an article was done on how I installed Macs into a newspaper business, so I've been loyal to Apple for a long time. I think the expectation that the machine work, without my knowing how to do something with "firmware" isn't unreasonable.

Hi all,

Not sure if this solution has already been mentioned, if it has my apologies.

Internet/wifi was running extremely slow on my iMac (2011) running El Capitan 10.11.2. Tried a few things suggested on this thread and also from the internet and made no difference.

Then I simply turned wifi off on my iPhone and then turned it back on and the internet on the iMac was back to full speed..... go figure?

Edit.... Internet on the iMac suddenly went slow again. Turned wifi off on the iPhone and it speeded back up. Looks like this isn't a great solution, can't really keep turning the wifi off and on the iPhone. Never had this problem before and everything was fine with Mavericks and even El Capitan 10.11.1

I have the same issue. I've a 70Mb/s fibre broadband service at home. It felt slow on my Mac so I ran some tests. My three year old Windows 7 PC that was £300 when new managed 55Mb/s down and 18Mb/s up on Speedtest.net in Chrome. My Android Nexus 6 phone managed 68Mb/s down and 19Mb/s up using the Speedtest.net app. My £2000 Mac managed barely 6Mb/s down, whether running Speedtest.net in Chrome, Safari or Firefox. I've tried all the technical tips in this thread - nothing works. Someone else had noticed it speeds up the closer you get to the access point and I've seen this too. Randomly it will speed up into the mid teens but then revert to single figure speeds, which is the norm. If I use it wired I get similar results to the Nexus. This looks very much like a driver issue to me, something in El Capitan's core workings. This is my first Mac and I can't tell you how peed off I am. I've grounds to take the thing back and get a full refund, which I will be doing if they don't fix this soon.

I've done more fiddling and it seems my Mac's WiFi is more sensitive to signal levels and WiFi congestion than my other devices. I live in a block of flats with fairly heavily congested spectrum. My other devices happily deliver full bandwidth but in the same location just a few meters from the access point the Mac has dropped its WiFi down to single digit Mb/s. I've already tweaked my WiFi to get the most out of it (picked the quietest channel) so there's nothing I can do about this but other users could see improvements if they optimise their coverage and/or channel selection as others have advised further up this thread. This could be an antenna sensitivity issue or a driver. Having never tested my Mac on Yosemite I've no idea if El Capitan made it worse or better. I'm not at all optimistic it'll be fixed and it's a shockingly poor performance from a premium product.

I was struggling and went through this and my house mate suggested I change my DNS settings which I had done before but to no avail. Either way his suggestion worked.
System Preferences > Network > Advanced > DNS > Add new DNS (8.8.8.8) > Remove old DNS.

Hope this works for everyone as before that fix this page took 10 minutes to load whereas now it took under 5 seconds.

Has Apple responded anywhere on this post? I am not happy.  My modem/router combo is new enough that there are no firmware updates. I have tried every random suggestion I can find on this thread and the internet in general, and I am completely up to date in my Yosemite version. I have to turn wifi off and on ALL DAY long.  I work via VPN connection frequently - this has become impossible. My first Mac, and I am full of regret.

I'm at a loss as to what to do/try next...?