Optimizely
Run Optimizely Web experiments only after visitors allow experience. A withdrawal reloads the page, and Optimizely stops.
Inth keeps the consent record of each choice, with the visitor’s country and the policy that applied.
pnpm add @c15t/integrationsThe snippet does not load. The optimizely global, Optimizely cookies and optimizely_data$$ keys are absent.
Before you start
You need an Inth project that connects to your app, c15t in that app and your Optimizely project number. Find it before .js in the snippet URL under Settings > Implementation.
New to c15t? Complete the quickstart for your framework first. Keep its Inth endpoint, policy, styles and consent UI.
Open the quickstart for your frameworkHow consent works with Optimizely
Before experience has permission, the c15t optimizelyWeb helper creates no Optimizely global and sends no Optimizely request.
After permission, c15t adds the snippet to the head with async: false. Optimizely starts its experiments when the snippet runs.
The SDK cannot unload after it starts. So on withdrawal, c15t removes the snippet and reloads the page. The new page blocks the snippet until the next grant.
Visitors can see the original page before Optimizely applies a variation. Plan your experiments for this flicker and for visitors who do not give consent.
Read the Optimizely snippet guideInstallation
Optimizely has one load mode in c15t. The helper waits for experience permission.
Wait for permission. No request goes to Optimizely until the visitor accepts experience. On withdrawal, c15t reloads the page.
optimizelyWeb({ projectId })An opt-out policy or no policy gives optional categories permission before a choice. Then Optimizely loads on the first page. This guide uses an opt-in policy.
Setup steps
Install the integration package
Add the helpers next to c15t. An import alone does not start Optimizely.
Add your project number
The helper loads https://cdn.optimizely.com/js/<projectId>.js. Use a category condition such as { and: ['experience', 'measurement'] } if your policy needs both.
src/consent-scripts.ts A blank or non-numeric project number logs an error, and the snippet does not load. Use one Optimizely snippet per page.
Register it with your existing setup
Add scripts to the c15t configuration that you have now. Keep your Inth endpoint, mode, policy, styles and consent UI.
Add scripts to c15t.config.ts, next to next.config.ts. Keep the rest of your config, such as mode, in the same call. App Router, Pages Router and static export read the same file.
c15t.config.ts Pass scripts to the ConsentRoot in your root route. Import helpers in the route module, not in a server function: script configurations carry callbacks.
src/routes/__root.tsx Add scripts to the options of your ConsentProvider, next to mode. Keep the banner, dialog and preferences link inside the provider.
src/consent.tsx Register scripts under the c15t key in app.config.ts. Keep them out of nuxt.config.ts, which reaches the browser as JSON and drops the helper callbacks.
app/app.config.ts Pass scripts to the c15tVue plugin call you have now. The plugin starts one script loader when the app mounts.
src/main.ts Add scripts to the client entrypoint, which the integration finds on its own. Keep helpers out of astro.config.mjs: its options are serialized into the page.
src/c15t.client.ts Pass scripts as a prop to the ConsentProvider you have now. The provider owns the loader and disposes it on unmount.
src/App.svelte Add scripts to the ConsentRoot in the root layout. Import helpers in the layout component, not in +layout.server.ts: a server load cannot send functions to the browser.
src/routes/+layout.svelte Paste the vendor’s snippet behind consent
The helpers need a bundler. On a page with the c15t script tag, paste the vendor’s own snippet instead and keep it inert until visitors allow its category. Helper options, such as loadMode, do not apply.
index.html Pass scripts to init() from @c15t/browser, next to your mode. With createConsentRuntime, pass scripts to it instead.
src/consent.ts
Remove the original Optimizely snippet and each tag manager copy. For an opt-out that stays, call optOutOptimizely(). It sets a ten year optimizelyOptOut cookie that a later grant does not clear.
Verify your setup
Use your own test project and a clean browser profile with an opt-in policy. Open DevTools Network and filter by optimizely.com. Then test the three states.
Before a choice
The snippet does not load. The optimizely global, Optimizely cookies and optimizely_data$$ keys are absent.
After you allow experience
The project .js request appears, and window.optimizely.get is a function. Check experiment behavior in your test project.
After you withdraw experience
Save your choice. c15t reloads the page, and the snippet stays blocked. Allow experience again and make sure that experiments come back.
A reload keeps cookies and localStorage. Use the clear on revocation setting of your framework to remove the storage that your site uses.
Open the full Optimizely guide