demo · v138

Speculation Rules moderate (mobile-improved)

Pick an eagerness level. The page injects a real <script type="speculationrules">, then logs which links the browser pre-warmed. On mobile in 138, "moderate" now fires on touchstart and on viewport intersection — much closer to "conservative" timing than before, when it was too eager.

checking support…

change eagerness / hover or tap a link, then watch the log

Mobile improvement: moderate now fires on touchstart and IntersectionObserver visibility, instead of immediate hover-equivalent that wasted bandwidth.

the code

{
  "prefetch": [{
    "source": "document",
    "where": { "href_matches": "/v*/*" },
    "eagerness": "moderate"
  }]
}

see also