64% of the Mobile Web Still Runs jQuery, and Those Sites Are Faster

    jQuery is supposed to be the slow legacy library you should drop. We checked 9.5 million sites: the ones still running it pass Core Web Vitals more often on mobile (44.2% vs 39.0%) than the ones without it, because the sites that dropped it moved to heavier frameworks.

    Core Web Vitals pass rate, jQuery vs no jQuery (mobile)
    With jQuery
    44.2%
    Without jQuery
    39%

    Source: PageSpeed Matters analysis of 9.5 million origins with CrUX field data, May 2026.

    The sites still running the old library pass 5.2 points more often than the ones that moved on.

    Good responsiveness (INP), jQuery vs no jQuery (mobile)
    With jQuery
    89.8%
    Without jQuery
    76.1%

    Source: PageSpeed Matters analysis, mobile 75th-percentile field data, May 2026.

    jQuery sites do not carry the thing that makes pages slow to respond: a heavy client-side JavaScript framework.

    Source: 64% of the Mobile Web Still Runs jQuery, and Those Sites Are Faster - PageSpeed Matters