Archiveror is a browser extension that archives webpages by submitting them to archive.is, archive.org and other archiving services. These archives are publicly available, so you then have a backup that you can refer to in case the original falls prey to link rot.
Archiveror also preserves your bookmarks by automatically archiving them in the background. Its icon changes when you visit a bookmark it has archived, clicking on it shows the archive links. Archiving of bookmarks happens when you make a new bookmark and when you open an old bookmark. This can be disabled.
You can manually archive webpages by clicking on the icon, using the Alt+Shift+Y hotkey (configurable), via the page’s right click context menu, or by right-clicking on links on a page. The URL for the archive is then copied to your clipboard, so you can easily paste the link for references and citations.
Archiveror supports several online archiving service. When clicking on the icon, you’ll see an “Archive Now” button. You can select which archiving services to use when you click this button at the options, there you can also select multiple services to archive a single page at multiple web archives.
Archiveror also makes local copies of webpages. It saves one webpage in a single MHTML file. Save pages manually by either clicking the button or by pressing Ctrl+Shift+S. The filenames end with the UTC date and time of when the archive was made.
To enable local archiving of bookmarks, right click the Archiveror button, go to the options and then select “MHTML” at the “Bookmarks” section. With this option enabled your bookmarks will be saved in your Downloads directory following your bookmark structure. If you move your bookmarks around, Archiveror will mirror your changes and likewise move your local archives. For this to work you need to check “Allow access to file URLs” at the extensions page. Go to your extensions and enable it: https://i.imgur.com/ahrfe3M.png.
Local saving is currently only available for Chromium, vote for this bug if you want this feature on Firefox. Alternatively consider the Save Page WE add-on.