Python 3.14 webbrowser regression when launching vscode:// URI on macOS

[skissane-medallia]

Bug report

Bug description:

In Python 3.13.13 on macOS 26.3.1, I run __import__("webbrowser").open("vscode://"): it opens Microsoft VS Code
Same machine, in Python 3.14.2, same code: opens Chrome instead

I observe the same behaviour with Python 3.15.0a8

One line test case (using uv):

uv run --no-project --python=3.14 python3 -c '__import__("webbrowser").open("vscode://")'

In my actual use case, the URI is more complex, something like vscode://vscode-remote/ssh-remote+MYDEVBOX.example.com/workspaces/MYPROJECT.code-workspace – but vscode:// is enough to reproduce it

CPython versions tested on:

3.14

Operating systems tested on:

macOS

[skissane-medallia]

From looking at the code, I believe this was introduced by #130535 – that PR appears to assume you only ever want to open custom URI schemes in an actual web browser. But in reality, for an application-specific URI scheme such as vscode:// or slack://, the browser probably doesn't know how to handle it, the OS-registered application does.

[edvilme]

That is most likely an issue with your browser not knowing how to handle the application-specific URI
When it opens Chrome, what does it show? Also, what happens if you attempt to open the URI from the terminal?

open vscode://vscode-remote/ssh-remote+MYDEVBOX.example.com/workspaces/MYPROJECT.code-workspace