I'm helping a small business update its website, but the owner has no idea what platform it was built on. The original developer is gone, and they only have access to the hosting account. The site has a blog, product pages, and a few custom features, so I don't want to assume it's WordPress and start making plans around that. Is there a reliable way to identify the CMS without having access to the admin panel?
A public page can still reveal quite a bit about what is running underneath it, even when the login area isn't obvious. Scripts, paths, headers, and generated markup often leave enough clues to narrow down the possibilities. Try this CMS checker: https://pr-cy.io/cms-checker/ . Treat the result as a starting point and compare it with what you find in the hosting account. Some sites hide or modify the usual CMS signatures, so a tool may not always identify the platform correctly.
Hosting access gives you a lot more to work with than the public site alone. Look through the file structure for directories, configuration files, and naming patterns that belong to a particular CMS. WordPress, Joomla, Drupal, and other systems usually leave fairly obvious clues once you're inside the account. That can also help you tell whether the site is mostly running on a known CMS or whether the previous developer built a lot of it around custom code.