why does my MacBook Pro work on my home Wi-Fi, but no other Wi-Fi, public or private?

I’ll assume none of these other Wi-Fi networks require either a RADIUS or 802.1X or MAC-based login security, nor access to a web portal login to access the network; that these are all using WPA2 AES or better security and a pre-shared key.

If so…

Create a new network location in System Preferences > Network, and add the new Wi-Fi network there, and see if you have a corrupt location entry.

we can't really debug "no others work".

If you wanted to go try to connect to a specific network, readers would be happy to work with you.

The first question I would ask is whether a login page is required by the network you are connecting to, like at Airports and Hotels.

If yes, and you never get the form to fill out, try entering this strictly numeric address in Browser SearchBar:

1.1.1.1

If you get the CloudFlare splash page, you have accessed the Internet to get it. If you get the login page from the Network, you can proceed to log in and get something done. if that works, but nothing else does, you may have a Domain Name Server (DNS) issue such as specifying 0.0.0.0 as your DNS server.

Note: CloudFlare is NOT part of the solution -- they just have the absolute easiest to remember numeric IP address.

what does:

system preferences > Network

say as the Wi-Fi status?

if "connected", try the 1.1.1.1 in the Browser test, as you may have a DNS issue.

what shows as your DNS when you have an acceptable connection?

Are you using any third-party anti-Virus software? That has been know to wreak havoc on your ability to make connections. On an already well-protected MacBook Pro, it adds nothing -- only using up resources and making your Mac unstable.

Are you using any third-party VPN software? these are sold as a way to increase security of your Mac. They do nothing of the kind, and you security was not substantially at risk to begin with.

The "litmus test" to determine whether added software is to Blame is to restart in Safe Mode.

Safe Mode does a number of different things. Hold shift at startup, but have your userid and password at the ready.

A parade of unusual things happens.

• Your Mac loads just enough of the kernel to do a disk check. Then it proceeds to do a disk check. This can take an extra about five minutes.

• your userid and password are required, even if you normally auto-login. So have them handy.

• Your Mac adds ONLY a minimal set of Apple-Only extensions, Not including graphics acceleration extensions. Screen updates will therefore be wonky and slow, and the screen may re-draw multiple times, but it ultimately should be accurate.

• Your Mac assumes defaults for as many settings as possible. This is the key for re-setting the screen, but there is a little more to it: Resolution is likely to be lower and settings ordinary. Use this as a starting point to customize settings to your liking.

Any changes you make in Safe Mode will "stick" in regular mode after you restart.

• after restart in normal mode, your Mac will take slightly longer to start up [once] because it rebuilds some system caches.

"Works in Safe mode, fails in regular mode" implies "It's something you added".

Farles1 wrote:

You sir have just solved the issue that I have been plagued with for the past year! I can’t thank you enough! If you feel like explaining, I would love a better understanding of how/why this worked and what the underlying problem was.

The location entries can sometimes become corrupt, and few (none?) of us here have had the necessary access to a corrupted entry and to the underlying Wi-Fi configuration code to analyze and determine why, but we do know that weird networking problems on macOS can sometimes be cured through creating a new location entry and trashing the old. Probably not the answer you want, but…

what model-year MacBook Pro and screen size? what version MacOS?

Some possible things to try here:

https://appletoolbox.com/solved-macbook-connects-to-wi-fi-but-has-no-internet-connection/

Is it possible there is a proxy set in System Preferences -> Network -> WiFi -> Advanced -> Proxies ???