Page Weight: Why Bytes Still Matter
The HTTP Archive’s long-running data shows that the median web page now ships ~2.4 MB to mobile devices. That weight is paid for by your users — every byte costs them battery, data, and time. Google’s Core Web Vitals don’t directly measure size, but Largest Contentful Paint and Interaction to Next Paint correlate strongly with how heavy your page is.
What this tool measures
We download the HTML, then walk every <link>, <script>, <img>, srcset, <source>, video/audio source, preload, and icon link. For each external resource we send a HEAD request (falling back to GET when servers reject HEAD) and record the response’s actual size. Inline data: URIs are listed but not counted.
Performance budgets that work
For mobile-first sites a useful budget is roughly: HTML ≤ 100 KB, total CSS ≤ 100 KB, total JS ≤ 350 KB (parsed/compressed), images ≤ 1 MB on the initial viewport, and a total weight under 1.5 MB. Heavier pages are still possible to make fast — but they require very deliberate optimisation (HTTP/3, Brotli, lazy-loading, image responsive variants, font subsetting).