Blogspot addresses, country redirects and custom domains
Blogger blogs live at yourname.blogspot.com by default, and that address is what most people still share. It's a good thing to encode: it's short, it's stable for as long as the blog exists, and it works whether someone scans it on a phone or a desktop.
One quirk worth knowing: Blogspot sometimes redirects visitors to a country-specific domain, so the address in a scanner's preview may not match exactly what you encoded. That's normal and the blog still loads — it's also why availability checks on blogspot names have to ignore redirects.
If you've connected a custom domain, encode that instead through "Any link". A domain you own is the most durable destination for anything printed, because you keep it even if you move the blog to a different platform later.
Everything happens in your browser. The QR encoder is built into this page, so your username is never sent to a server, nothing is logged, and there's no daily limit. The code is static — the link lives in the pattern itself, with no redirect service in the middle that can expire, start charging or go down.