iphone 16 network speeds/connectivity

Do you experience the same problem on another network? For example, the wifi network at the Apple Store? Starbucks? McDonalds?

If not, the problem is the configuration of your WiFi network.

There are lots of things that can bork performance with a specific device/chipset/etc.

It's not just a matter of signal strength. I'm currently fighting a battle with a WiFi adapters for windows pc's that use a specific chipset on my corporate Cambrium network with over 200 access points and 6 separate VLANS. Those devices drop connections regularly and experience extremely poor performance. Everything else is fine... And the problem devices work just fine when connected to any other Brand of access point we've been able to find with what should be identical settings for the network.

Mvpmvpmvp wrote:

Thanks! Are you saying the iPhone 14 would have a different client than an iPhone 16? This is the kind of think I suspected was happening: something specific for iPhone model. That fits the data for the differences between speeds of iPhone 14 and iPhone 16 while the same behavior of two iPhone 16s.

Different devices can use different Wi-Fi chipsets and can utilize different features of the Wi-Fi standards and also of IP networking, as well as band steering or WPA3 support or other details.

This for all Wi-Fi stations too, whether clients or routers or access points or bridges, as all parts of the connection involve non-trivial hardware and firmware and related processing.

This absolutely includes the eero and the mesh networking as potentially being flawed here, too.

Your own testing tends to point at the eero or its configuration or local network environment as the common factor here too, and not at the iPhone.

What troubleshooting and diagnostic tests and A-B tests have you run, beyond your reported use of a speed-checking website service?

Local performance tests? Tested whether local network performance is good or bad? At its simplest, timing the transfer of a file near the available capacity of your iPhone, to or from a local storage server.

Tried different online performance testing tools? Different testing websites and different tests can use different network paths, and different ISPs can have different policies or practices around these bandwidth-testing services.

Performance tests performed on different Wi-Fi networks?

Check the capabilities and firmware of the local Wi-Fi network? Maybe band steering?

Checked for local Wi-Fi interference? There are shortcuts that provide basic Wi-Fi info, but a Mac or PC has a better view of potential Wi-Fi issues with a tool such as WiFi Explorer. Getting directed onto congested 2.4 GHz or the ever-popular cascading channel renegotiations will hammer performance.

Your postings are unfortunately lacking in technical or engineering details, so I’m guessing here, and am regrettably quite probably repeating things already considered or tested.

In no particular order…

I prefer to run mostly wired access points with some mesh access points, and performance on the mesh can range from just fine, to bad.

On macOS, I use WiFi Explorer app for troubleshooting, as well as the tools built into the local network.

The local networking gear runs continuous ISP connectivity, and can selectively run ISP speed tests directly. I don’t need apps for that, though I can trigger ISP performance tests from the client apps. Local performance is usually running up a big transfer or a continuous stream (from local or remote) and watching the graphs.

Check what tooling eero offers.

I prefer to avoid making assumptions when troubleshooting too, preferring to create and verify different configurations. Which is what I am suggesting here, and in previous replies. Both for local traffic, and for whatever other traffic may be nearby, as well as reviewing Wi-Fi configurations and settings and firmware.

Too much of the Internet is held together with problematic equipment, corrosion, zip ties, and hope. 😉

But this all reeks of an issue the eero gear (whether hardware, firmware, or configuration) might be having with this particular Wi-Fi client, or with Wi-Fi features this Wi-Fi client is using. And yes, it’s possible this is an issue common to two different iPhone 16 devices, but that’s still a discussion with eero.

I have an iPhone 16 Pro Max and I have Xfinity for my ISP. While I have nodes in other parts of my house, when near my Xfinity router, I get about 450 down and 45 up. The further away from the router, it does go lower, but for the most part never below about 120 down. It seems strange as to why you cannot get better readings for the iPhone 16, but I cannot figure out if it is only getting connections that low that it isn't showing up as a problem when the device is tested.

If you are sitting next to your router and power the iPhone off and back on again, do you still get those bad readings?

Still reeks of Wi-Fi issues; of Wi-Fi compatibility with this particular client, or with some feature this client is using.

Mvpmvpmvp wrote:

I purchased an iPhone 16 in March 2025. It had a lot of issues with internet speeds. I also have an iPhone 14 with Verizon. The iPhone 16 has T mobile as the carrier. I put both phones in airplane mode to remove the cellular differences/effect and used Ookla to check internet speeds on the two phone side by side at the same time. The iPhone 14 got 450 Mbps and the iPhone 16 consistently got 5 Mbps. Apple ran tests on the iPhone 16 at the store and said it was fine but it wasn’t. Finally Apple did an exchange of the iPhone 16 but the the new one is doing the same thing. It is NOT my internet!!! All the other devices report excellent speeds. Is turning off cellular enough to fully eliminate the factor of the cellular provider effect on internet speeds? Is this a known issue with iPhone 16s? If it is I would trade this crappy iPhone 16 in for an iPhone 14. BTW, I have spent many hours on the phone and at the Apple Store with their tech support people who did the regular things like resetting the network, running diagnostics, etc. Please do no just suggest the normal things. I am really looking for insight here into how and why this could happen. I am so fed up with this problem!! Help!!

What else do you want, you've already taken the device to Apple and they did what they could for you.

This is user to user technical forum there is no Apple here.

Mvpmvpmvp wrote:

Well that was a helpful response…..NOT.

I know this is a user to user forum. I am looking for insights with other users who have seen this before. If you have nothing to offer please do not respond.

Yes that the RIGHT attitude, users are now going to flock into this thread and provide you insightful details on how to solve your problem.

I’m going to assume this is a Wi-Fi test, and not a cellular test. Though that’s not entirely clear.

If you don’t tell us all of what was already tried, expect suggestions to be repeated.

Given everything you’ve reported, your local Wi-Fi configuration appears to be having issues with this client. (This guessing that other Wi-Fi networks have been tested, and guessing that those other Wi-Fi networks perform.)

Which Wi-Fi vendor and model is involved here, how complex is the network, how old is the gear, and is the firmware current? Wi-Fi 6 or 6E, with WPA3 enabled?

Any add-on security apps, add-on VPN apps, add-on MDM profiles, network content filters installed or at the router or in your network configuration, or other such apps involved?

Again, what data wasn’t provided will be asked anew.

Apple ran tests on the iPhone 16 at the store and said it was fine but it wasn’t.

When you took the original iPhone 16 to Apple for testing......I am not clear on whether the speed problem was confirmed at that time.

If Apple really did test the phone at that time, I don't think they would say that the iPhone checked out fine.....if it didn't.

Yes, I understand that you later received a replacement phone. Wondering if Apple tested that phone as well.

Can you provide a few more details on this to clarify?