[Home](./index.md) > [puppeteer](./puppeteer.md) > [Protocol](./puppeteer.protocol.md) > [ServiceWorker](./puppeteer.protocol.serviceworker.md) > [ServiceWorkerRegistration](./puppeteer.protocol.serviceworker.serviceworkerregistration.md) > [registrationId](./puppeteer.protocol.serviceworker.serviceworkerregistration.registrationid.md) ## Protocol.ServiceWorker.ServiceWorkerRegistration.registrationId property Signature: ```typescript registrationId: RegistrationID; ```