Similar feature-set at first glance, but not open-source, not free after beta ends, and created/maintained by an unknown solo developer. Nice site design, but I think the cards are pretty heavily stacked against this one.
The big difference is Checkbot crawls whole websites as opposed to checking a single page at a time. The Checkbot interface is designed around helping you hunt down issues that impact groups of pages and pages you didn't think to check. For example, this lets you find duplicate title/description/content issues and root out pages with broken links and invalid HTML you don't look at often.
That does sound like a key differentiating feature, thanks for clarifying. While I'd probably prefer to hook up an open-source web-crawler to lighthouse (e.g., something like github/lightcrawler [1]), I could see SEO/marketing experts in particular paying for a user-friendly all-in-one solution like this versus cobbling something together from open-source tools.
Yes, so I think the UI is a really important factor here in terms of productivity and ease of use. For example, after Checkbot has scanned your localhost/development site and identified a page has the same title as other pages, you can edit your site, hit the "recrawl" button for that page and confirm your fix worked in a few seconds. Users I've worked with so far have really appreciated this fast and simple workflow.