www.ucar.edu speed test — 20 Oct 2026

What these numbers mean

• The first byte arrived in 312 ms. That is workable, and the cheapest win left is caching or a warmer connection.
• The page transfers 1.59 MB over 23 request(s). Images files are 79% of it, so resize and recompress the largest images before anything else.
• The HTML itself arrives gzip-compressed.
• It runs over HTTP/3, so the assets share a connection instead of opening one each.
• The largest element painted at 812 ms, inside the 2.5 s Google calls good.
• Layout stayed still (CLS 0.014), so nothing jumps under the reader's cursor.
• The main thread was blocked for 78 ms in total, which is not enough to feel.

Fix first: Image delivery and format - Serve WebP or AVIF with a JPEG fallback, size images to the space they occupy, and lazy-load anything below the fold. Images are usually more than half of a slow page.

Read on one shared server, not a visitor's phone: use it to compare pages against each other, not as a promise about every connection. We fix what these tests find.