Ryu Hi Den, TLS 1.3 and HTTP/3 are related, but they are not the same thing. TLS 1.3 means the HTTPS handshake can use the newer TLS version. HTTP/3 specifically means the site is being served over QUIC/UDP instead of HTTP/1.1 or HTTP/2 over TCP. A quick way to test what your site is actually negotiating is: curl -I --http2 yourdomain.com curl -I --http3 yourdomain.com or in Chrome DevTools: Network tab → right click columns → enable Protocol If you see h2, that is HTTP/2. If HTTP/3 is active, you’d usually see h3. From the current Vercel docs I can find, Vercel explicitly documents TLS 1.2 / TLS
Den.D Hi @ryux1 , thanks fro the reply. You hit the nail on the head. As I mentioned in my post, even though the two things aren't directly connected, I don't understand the logic of supporting only TLS 1.3 and not HTTP/3. This is especially true when even the cheapest shared hosting providers ($10–$20/month) offer HTTP/3 by default. Of course, there's no personal setting for that, being a platform lack... My post was just a rant, hoping that someone in Vercel reads it and acts to solve the gap 🙂
Ryu Hi Den, Yep, fair point. I mostly replied to clarify the TLS 1.3 vs HTTP/3 difference for anyone else reading the thread. I agree there probably isn’t anything to configure at the project level right now. It would be nice to have HTTP/3 support on Vercel too, or at least a clear note in the docs about the current status. Thanks for raising it.
system There's another community post with 404 debugging tips that might be helpful. Please give these solutions a try and let us know how it goes. community.vercel.com/t/debugging-404-errors/437 A human should be around soon to offer more advice. But you can also get helpful information quickly by asking v0.
Amy Egan There are a lot of possible causes. I hope you were already able to solve it using the tips shared by the bot. If not, it would be helpful to see the site and code to get a better understanding of what's going wrong in this case. Are you able to share a minimal reproducible example or a publicly accessible URL for the site?
system There's another community post with 404 debugging tips that might be helpful. Please give these solutions a try and let us know how it goes. community.vercel.com/t/debugging-404-errors/437 A human should be around soon to offer more advice. But you can also get helpful information quickly by asking v0.
Ryu Hi Solomon, The Functions tab only showing /api/auth/[...nextauth] is not necessarily a problem by itself. Static App Router pages will not always show up there as functions. The more important signal is the exact 404 type and which URL is returning it. I’d separate three cases: Unique deployment URL returns 404 Project/production alias returns 404 Only specific app paths like /todo return 404 Can you test the unique deployment URL from the deployment details page, not just the project alias? curl -I https://<deployment-id-or-unique-url>.vercel.app/ curl -I https://<deployment-id-or-unique-url
system The domain troubleshooting guide can help with most custom domain configuration issues. You might be able to use that guide to solve it before a human is available to help you. Then you can come back here and share the answer for bonus points. vercel.com/docs/projects/domains/troubleshooting You can also use v0 to narrow down the possibilities.
Ryu Hi Hero, I’d first separate “Safari is slow to get the document” from “Safari gets the document quickly but renders a blank page for a while.” A quick way to check is to run this in Safari’s console after a slow load, then compare it with Chrome on the same iPhone: const n = performance.getEntriesByType("navigation")[0]; console.table({ dns: Math.round(n.domainLookupEnd - n.domainLookupStart), connect: Math.round(n.connectEnd - n.connectStart), tls: Math.round(n.requestStart - n.secureConnectionStart), ttfb: Math.round(n.responseStart - n.requestStart), download: Math.round(n.responseEnd - n.r
system The domain troubleshooting guide can help with most custom domain configuration issues. You might be able to use that guide to solve it before a human is available to help you. Then you can come back here and share the answer for bonus points. vercel.com/docs/projects/domains/troubleshooting You can also use v0 to narrow down the possibilities.
js I'm seeing the same problem on one of my three projects. I've tried both Chrome, incognito Chrome, and Firefox, all with the same issue. I'm on a mac. Nextjs as well.
js And now it's fixed.