--- 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