Answer

Can PWAs read and write files?

Short answer

Yes on Chromium browsers (Chrome, Edge, Opera). The File System Access API lets a PWA open, read, edit and save files with the user’s permission — Figma, VS Code Web and Excalidraw use it in production. iOS Safari and Firefox fall back to the standard `<input type="file">` and downloads.

By InstantPWA engineering·Reviewed July 22, 2026

What Chromium supports

File System Access API: showOpenFilePicker, showSaveFilePicker, showDirectoryPicker. Handles persist across sessions with IndexedDB.

What everyone supports

File input (`<input type="file">`) for reads, Blob + anchor download for writes. Works everywhere but requires user interaction each time.

Feature-detect and degrade

Check `'showOpenFilePicker' in window` and fall back to the classic pattern on iOS Safari and Firefox.

Sources

Related

Can a PWA access the camera?

Yes. A PWA can access the camera, microphone, geolocation and file system through the same Web APIs a regular website uses (getUserMedia, showOpenFilePicker, Geolocation). Every capability requires explicit user permission and works cross-platform, though a few APIs (Bluetooth, USB, NFC) are still Chromium-only.

Do PWAs work offline?

PWAs can work offline, but only for content their service worker has explicitly cached. Registering a service worker does not automatically make a site offline-capable — you decide what to cache (app shell, API responses, images) and what strategy to use (cache-first, network-first, stale-while-revalidate).

Can PWAs use Bluetooth?

Partially. The Web Bluetooth API works on Chrome, Edge, Opera (desktop and Android) and Samsung Internet — enough to connect to BLE peripherals like heart-rate monitors, printers and IoT devices. iOS Safari and Firefox do not support it, and Apple has stated no intent to ship it.

What is a Web App Manifest?

A Web App Manifest is a JSON file — usually manifest.webmanifest — that declares your app’s name, icons, start URL, theme colour and display mode. Browsers read it to decide whether to offer the install prompt and what icon and name to show on the home screen.

How do you add a PWA to the home screen on Android?

On Android, open the site in Chrome, tap the three-dot menu, and choose "Install app" (or "Add to Home screen" on some versions). If the site meets installability criteria, Chrome may also show an automatic install banner or mini-infobar without you having to open the menu.