If I go to a website such as https://vercel.com/ it works, but if I go to https://vercel.com./ it doesn’t because of the trailing dot and it happens for every domain on vercel (it’s an edge case I know but the HTTP protocol is able to handle that also)
Hi SkyMesh Dynamics,
This is a real edge case, but I’d frame it as DNS/TLS/host normalization rather than an HTTP routing issue.
A trailing dot is valid in DNS because it represents the fully qualified domain name:
vercel.com.
But for HTTPS there is another layer before HTTP routing: TLS certificate selection via SNI. If the browser/client sends the SNI/host as vercel.com. and the edge does not normalize it to vercel.com before certificate/host matching, the request can fail before the app or redirect logic gets a chance to run.
You can compare both cases with:
echo | openssl s_client -connect vercel.com:443 -servername vercel.com -brief
echo | openssl s_client -connect vercel.com:443 -servername vercel.com. -brief
If the no-dot version succeeds and the trailing-dot SNI version fails, that confirms it is happening at the TLS/edge hostname layer, not inside a Vercel project.
For app owners, I don’t think there is a reliable project-level workaround for https://example.com``./, because a redirect would require the HTTPS request to complete first. The practical workaround is to avoid generating canonical links, redirects, sitemap URLs, or shared URLs with the trailing dot. For Vercel itself, this would likely need edge-level hostname/SNI normalization if the platform chooses to support that form.