The easiest way to save a web page is to download it to your computer. In Chrome, open the three-dot menu and select More Tools > Save page as. For Firefox, open the hamburger menu and choose Save Page As. On Safari, go to File > Save as or File > Export as PDF, and in Microsoft Edge, open the three-dot menu and choose More tools > Save page as.
You can also right-click anywhere on the page and select “Save as” with any web browser, or use the keyboard shortcut Ctrl S in Windows, Command S in macOS.
Chrome can save the complete web page, including text and media assets, or just the HTML text. Edge can do the same, but will allow you to download multiple files, all in one file, or HTML only. Firefox, meanwhile, will give you a choice between the complete package, an HTML file, and a simple text file. On Safari, you can pick between Web Archive (all text and media assets) or Page Source (source text only).
Download the file you prefer to your computer and read the page at any time. The web page will load as a local file and can work even if you have no internet connection.