Tested 2026-07-30 19:02:05 using Chrome (runtime settings)
The top lists point out the specific files to fix first: the largest and slowest assets across all tested pages, and the assets returning visitors have to download again.
Every JavaScript byte is downloaded, parsed and executed on the main thread, so trimming the biggest bundles pays off twice.
| url | time since last modified | cache time | transfer | size |
|---|---|---|---|---|
| https://www.sitespeed.io/js/copy.js → run | -1 second | 1 year | 785 B | |
| https://www.sitespee...-timing-footer.js → run | -1 second | 1 year | 289 B | |
| https://www.sitespee...-timing-header.js → run | -1 second | 1 year | 196 B |
CSS blocks rendering until it is downloaded and parsed, so the biggest files delay first paint the most.
| url | time since last modified | cache time | transfer | size |
|---|---|---|---|---|
| https://www.sitespee...ss/NpD8aMgW5S.css → run | -1 second | 1 year | 5.8 KB |
Images are usually the easiest bytes to win back: resize them, compress harder or switch to a modern format like AVIF or WebP.
| url | time since last modified | cache time | transfer | size |
|---|---|---|---|---|
| https://www.sitespee...8bRaVGAJ-500.avif → run | -1 second | 1 year | 34.4 KB | |
| https://www.sitespee...5LbaEznK-180.avif → run | -1 second | 1 year | 6.9 KB | |
| https://www.sitespee...W60XTv4C-200.avif → run | -1 second | 1 year | 2.3 KB |
The HTML document is the first byte of everything: nothing starts rendering before it arrives.
| url | time since last modified | cache time | transfer | size |
|---|---|---|---|---|
| https://www.sitespeed.io/ → run | -1 second | 0 seconds | 6.1 KB |
The largest favicon files across the tested pages.
| url | time since last modified | cache time | transfer | size |
|---|---|---|---|---|
| https://www.sitespee.../sitespeed.io.ico → run | -1 second | 1 year | 2.9 KB |
These assets took the longest time to download. Everything that waits for them (rendering, other requests on the same connection) is held up too.
| url | type | time since last modified | cache time | transfer | size | timing |
|---|---|---|---|---|---|---|
| https://www.sitespeed.io/ → run | html | -1 second | 0 seconds | 6.1 KB | 519 ms | |
| https://www.sitespee...8bRaVGAJ-500.avif → run | image | -1 second | 1 year | 34.4 KB | 434 ms | |
| https://www.sitespee...5LbaEznK-180.avif → run | image | -1 second | 1 year | 6.9 KB | 381 ms | |
| https://www.sitespee...-timing-footer.js → run | javascript | -1 second | 1 year | 289 B | 345 ms | |
| https://www.sitespee...-timing-header.js → run | javascript | -1 second | 1 year | 196 B | 344 ms | |
| https://www.sitespee...W60XTv4C-200.avif → run | image | -1 second | 1 year | 2.3 KB | 341 ms | |
| https://www.sitespee...ss/NpD8aMgW5S.css → run | css | -1 second | 1 year | 5.8 KB | 287 ms | |
| https://www.sitespeed.io/js/copy.js → run | javascript | -1 second | 1 year | 785 B | 278 ms | |
| https://www.sitespee.../sitespeed.io.ico → run | favicon | -1 second | 1 year | 2.9 KB | 65 ms |
