[▲ Vercel Community](/) · [Categories](/categories) · [Latest](/latest) · [Top](/top) · [Live](/live) [Help](/c/help/9) # Large static files fail to download via custom domain but work via .vercel.app 30 views · 0 likes · 4 posts Lumpov (@lumpov) · 2026-01-07 I'm experiencing an issue where large static JavaScript files fail to download when accessed through my custom domain, but work perfectly fine through the .vercel.app domain. **Project details:** * React & Vite * Custom domain: adminas.org * Vercel nameservers: ns1.vercel-dns.com, ns2.vercel-dns.com * Domain IPs: 216.198.79.65, 64.29.17.65 **Issue:** When requesting the main JS bundle through the custom domain, the HTTP headers return successfully (status 200, correct content-length), but the actual file content either: * Times out with 0 bytes received * Times out after receiving only \~10KB of \~1.7MB **Affected URL (custom domain - FAILS):** https://adminas.org/assets/index-BZZFp_s8.js * x-vercel-id: fra1::btchs-1767769066740-7d315e69c4f6 * content-length: 1751057 (1.7MB) * Result: Timeout, 0 bytes received **Working URL (.vercel.app - WORKS):** https://adminas-frontend-git-beta-lumpovs.vercel.app/assets/index-BZZFp_s8.js * x-vercel-id: fra1::rw6vp-1767769075594-be105d0dabeb * content-length: 1751057 (1.7MB) * Result: Downloads successfully in \~1.2 seconds **Additional observations:** * HTML page (https://adminas.org/) loads correctly (965 bytes) * CSS file (https://adminas.org/assets/index-B3tInvv7.css, 2.8KB) loads correctly * Only large files (JS \~1.7MB) fail to download * Browser shows ERR_HTTP2_PING_FAILED error * Issue persists regardless of DNS provider (tested with Cloudflare DNS and Vercel nameservers) * Same edge region (fra1) is used for both domains **Expected behavior:** Static files should download identically whether accessed via custom domain or .vercel.app domain. **Steps to reproduce:** 1. Open browser DevTools → Network tab 1. Navigate to https://adminas.org/ 1. Observe that HTML loads, but JS file stays in "pending" state indefinitely system (@system) · 2026-01-07 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](https://community.vercel.com/t/introducing-the-vercel-leaderboard/1358). https://vercel.com/docs/projects/domains/troubleshooting You can also use [v0](https://v0.dev/) to narrow down the possibilities. Jacob Paris (@jacobparis) · 2026-01-07 Are you using a VPN or any antivirus software? The ERR_HTTP2_PING_FAILED is usually caused by something intercepting the request, like TLS inspection or vpn reconnection Can you reproduce this on other devices or networks? Lumpov (@lumpov) · 2026-01-07 The error ERR_HTTP2_PING_FAILED does not always appear in Dev tools. Most often (failed)net::ERR_TIMED_OUT. **What I've Already Tried:** 1. Removed and re-added the custom domain multiple times 1. Switched nameservers to Vercel DNS (ns1.vercel-dns.com, ns2.vercel-dns.com) 1. Tested with Cloudflare DNS (CNAME to cname.vercel-dns.com, DNS only) 1. Verified SSL certificate is valid 1. Removed all custom headers from vercel.json 1. Tested from multiple networks — issue persists --- **Request:** Could you please investigate why the Vercel Edge servers assigned to custom domains (IP range \*.65) fail to deliver response bodies, while the servers assigned to .vercel.app domains (IP range \*.131) work correctly? **Vercel IDs for reference:** * Custom domain request: x-vercel-id: fra1::\* or arn1::\* * Project: adminas-frontend * Custom domain: adminas.org