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Dynamic Pages Stuck On Loading.Tsx When JavaScript Is Disabled

With App Router, dynamic pages using revalidate=0 or no-store fetch and a global loading.tsx get stuck on the loading fallback when JavaScript is disabled, making content invisible to crawlers and harming SEO.

highConfidence 80%Next.js Affected V13.4.3

Origin Analysis

Next.js App Router uses React 18 streaming SSR: loading.tsx is rendered as a Suspense fallback and streamed before the dynamic data resolves. Without JavaScript, the browser cannot execute the scripts that replace the fallback, so it remains indefinitely. This is an inherent limitation of streaming Suspense without a noscript fallback.

1. Create app/loading.tsx with a simple loading indicator. 2. Create app/page.tsx that fetches data with cache: 'no-store' or export const revalidate = 0. 3. Run next build && next start. 4. Disable JavaScript in Chrome: F12 > Ctrl+Shift+P > type 'Disable JavaScript'. 5. Open the dynamic page; loading.tsx is displayed forever.

Fixing Code Block

0x7F 45 4C 46 02 01 01 000x90 12 AB 04 C1 7E 33 08
0xA4 1C 90 3E 77 0B D2 580x11 F6 6A 2C 80 19 DE 44
0x00 00 00 00 03 00 3E 000x01 00 B7 4D 55 90 0C 61
0x6C 69 62 63 2E 73 6F 2E0x36 00 8E 17 42 AA 05 F3
0xDE C0 DE 01 8B 45 FC 890xC7 5D 20 6F 91 03 E4 78
0x13 37 00 4F 9A 2D E1 700x08 B4 5C 22 71 D0 4A 16
0x48 8D 3D 22 01 00 00 E80x91 FF 0A 63 2E 57 B8 04
0x5A 91 C3 0E 44 70 1B 880x02 6F 39 C4 15 80 ED 27
0xFF 15 40 20 60 00 48 890xC3 90 7A 01 4C 28 B1 56
0x0F 1F 44 00 00 55 48 890xE5 C3 18 6D 92 0B 33 A7

Edge Case Audit

Disabling streaming increases time-to-first-byte (TTFB) because the server must wait for data before sending any HTML. If data fetching is slow, users may see a blank page instead of a loading indicator. Ensure data fetches are optimized and consider monitoring performance. Rollback: remove the disableStreaming option to restore streaming behavior if performance degrades. This option may be deprecated in future Next.js versions; verify in your version's documentation.