Drupal can support a progressive web app, but “can” is not the useful question. The useful question is whether the product needs behavior that an ordinary responsive website cannot provide cleanly.
Start with the user situation. A field team that loses connectivity may need an offline queue and local data. A customer portal may benefit from installation and repeat visits. A public information site may need excellent mobile performance but gain little from service-worker complexity.
Choose the smallest architecture that meets the need
For many projects, keep Drupal’s rendered frontend and add only the browser features that have a clear use case. A web app manifest can describe an installable experience. A carefully scoped service worker can cache static assets or a small set of read-only pages. This preserves Drupal’s routing, access controls, previews, and editorial workflow.
A decoupled frontend is a larger decision. Drupal’s JSON:API can provide content to a JavaScript application, but the team then owns frontend routing, rendering, authentication, caching, previews, error states, accessibility, and SEO behavior. Choose that architecture because the interaction model requires it, not because “PWA” appears on a feature list.
Offline is a data-consistency problem
Caching a logo is easy. Letting someone read and update data while disconnected is not. The application needs rules for stale data, queued writes, conflicts, failed synchronization, device storage, and logout. Sensitive content should not remain available on a shared device merely because a service worker cached it.
Define exactly what works offline. A useful first release might cache the application shell and a user-selected set of read-only records while requiring a connection for edits. That is easier to explain and test than an ambiguous promise that the whole site works offline.
Push notifications require restraint
Push is appropriate when the information is timely, expected, and useful outside an active session. It also requires explicit permission, subscription storage, opt-out handling, expiry and failure cleanup, and a clear reason for each message. Do not ask for permission on the first page view. Ask in context, after the user understands the benefit.
Measure the constraint before adding machinery
If the problem is slow mobile performance, first measure payload size, image delivery, caching headers, backend response time, and third-party scripts. Drupal page caching, a CDN, responsive images, and less JavaScript may solve the problem without a service worker or separate frontend.
The right result is not the maximum number of PWA features. It is a product that behaves predictably under the network, device, security, and maintenance constraints its users actually have.