How do I open a web archive file on my Mac?

You can use Quick Look to view a .webarchive, or double-click it to open that content in a web browser. As already mentioned, you can also open it in TextEdit.

Open with TextEdit.

Choose an app to open a file on Mac

You can select which app you use to open a file. This is useful if you prefer to use a certain app, or if you don’t have the app that was used to create the file.

https://support.apple.com/en-uz/guide/mac-help/mh35597/mac