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Next 16.3 Regression: HtmlLimitedBots Matching Browser UAs Forces Cacheable PPR Pages To Private/No-Store

In Next.js 16.3, when cacheComponents is enabled and htmlLimitedBots is configured as a broad regex (e.g. /.*/), ordinary browser user agents matching the pattern are treated as limited bots, causing shouldForceDynamicPPRRender to become true. This disables SSG/cacheable PPR responses and emits private, no-cache, no-store, max-age=0, must-revalidate for all such requests, even though the route metadata is compatible with streaming. In 16.2.11 the same configuration kept browser requests cacheable. This regresses CDN cache hit rates and increases origin load.

highConfidence 85%Next.js Affected V16.3.0 Affected V16.3.1-Canary.0

Origin Analysis

Changes in PRs #96364 and #96367 converted htmlLimitedBots into an unconditional experimentalBypassFor rule and made shouldForceDynamicPPRRender = isRoutePPREnabled && !serveStreamingMetadata. For any non-empty user agent matched by the regex, serveStreamingMetadata is false, so all PPR requests are forced into dynamic rendering, bypassing SSG/prerender cache eligibility. The condition does not check whether the route's metadata is actually postponed or incompatible with the streaming shape, so even routes with compatible metadata lose their public cache policy.

1. Clone https://github.com/mdotk/next-163-html-limited-cache-repro 2. npm install 3. npm run build 4. npm start 5. npm run check 6. Observe that Chrome user-agent requests receive private/no-store in 16.3.0 while in 16.2.11 they were cacheable.

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

This change relies on accurate metadata flags in the prerender manifest. If those flags are missing or incorrectly set in certain PPR routes, the original metadata mismatch may reappear. Test extensively with real bot UAs (Googlebot, Bingbot) and with narrow vs broad htmlLimitedBots patterns before deploying. If any metadata-boundary or hydration error occurs, roll back to Next.js 16.2.11 or temporarily set a more restrictive htmlLimitedBots regex. Avoid using /.*/ in production as it intentionally matches all UAs.