BeamUsUp is a free Java-based crawler which quickly scans a website and reports on common SEO issues: status error codes, description/ title too long or missing, missing headings, duplicate content and more.
The program really is free. There's no cost, no stupid restrictions unless you upgrade, no adware, no flashing "Donate" button, no browser windows popping up at the developer's site. You don't even have to install anyway (as long as you've got Java, anyway) - just download the executable and run it.
The interface looks dull, but it's straightforward in operation, and you'll immediately see how to use it. Type your starting domain, press Enter; that's it.
After parsing robots.txt and sitemaps.xml, BeamUsUp starts scanning the URL and any subfolders. By default it doesn't scan subdomains or external URLs, but you can change that from the settings.
The program uses 10 crawler threads by default, so performance is reasonable. Results begin to appear in real time, too, with a sidebar listing individual problems and the number of pages where they've been found ("WARNING: title.too_long(43)"). Clicking any of these problem types displays their associated links, and you can view more details about them in a click or two.
When you've finished, the results of the scan may be saved as a local CSV file, an XLS, or directly to a Google Drive spreadsheet.