Optimization

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.

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 <head>:

import { buildPrefetchScript } from 'c15t';

const script = buildPrefetchScript({
  backendURL: '/api/c15t',
});
// Inject `script` into a <script> tag in your HTML <head>

Then create the store normally. Matching prefetched data is consumed automatically by the runtime during first store initialization:

import { createConsentManagerStore } from 'c15t';

const store = createConsentManagerStore({
  mode: 'hosted',
  backendURL: '/api/c15t',
});

Info

If overrides.gpc conflicts with the browser's ambient GPC signal, the prefetched entry is not reused and c15t falls back to a normal client /init.

Animation Performance

The default motion tokens are tuned for speed-first product UI:

Token	Duration	Used for
`fast`	80ms	Banner slide + overlay, card scale, button hover, widget entry/exit
`normal`	150ms	Accordion, switch toggle
`slow`	200ms	Dialog trigger snap, tab indicator

These defaults follow the principle that product UI should be fast and purposeful — animations exist for spatial continuity, not decoration. In benchmarks, animation duration contributes a constant floor to "data fetched → banner visible" timing. The default tokens sit at the lower end of standard UI ranges (80-200ms) to minimize that floor.

Reduce Network Overhead

If you must use a cross-origin backend URL, add preconnect so the browser starts DNS/TLS early:

<head>
  <link rel="preconnect" href="https://your-instance.c15t.dev" crossorigin />
</head>