Compression Dictionary Transport (RFC 9842) on Fastly Compute. Step 1 downloads d3 v7.8.5, which the browser stores as a dictionary. Step 2 downloads d3 v7.9.0, and the server sends only the delta.
| Asset | Wire bytes | Decoded bytes | Content-Encoding | Server decision |
|---|
Needs Chrome/Edge 130+ over HTTPS. After step 1, fully reload only if step 2 shows br fallback: the dictionary must be stored first.