--- title: Optimization description: Improve c15t startup performance with prefetching and network tuning. lastModified: 2026-03-17 --- Use this guide when you care about banner visibility speed, route static-ness, and reducing backend round-trip cost. ## 1) Prefer Same-Origin Proxy Proxy c15t requests through your app server so the browser calls your own origin instead of a third-party domain. ```ts const store = createConsentManagerStore({ mode: 'hosted', backendURL: '/api/c15t', // same-origin proxy path }); ``` Why this helps: * Same-origin requests avoid extra DNS/TLS setup in many deployments * Ad blockers are less likely to block your init endpoint * You can change backend infrastructure without touching client code ## 2) Prefetch Init Data Early Use `buildPrefetchScript()` to start the `/init` request as early as possible — before your app JavaScript loads. In production benchmarks with a same-origin rewrite, prefetching strategies show measurable improvement over client-only init: |Strategy|Scripts loaded|Data request starts|Banner visible| |--|--|--|--| |Client-only (no prefetch)|baseline|baseline|baseline| |Browser prefetch|\~1.3x faster|\~2.6x earlier|\~1.25x faster| |Server prefetch|\~2x faster|before page loads|\~1.9x faster| Add the prefetch script to your HTML ``: ```ts import { buildPrefetchScript } from 'c15t'; const script = buildPrefetchScript({ backendURL: '/api/c15t', }); // Inject `script` into a