How to run an HTML file as an app on Android or iPhone

Short answer: install Kapsula (free, Android and iOS), tap Add project, paste your HTML or pick the .html file. It opens as an app with its own storage and real notifications — no app store submission, no build tools, no account.

Why a browser isn't enough

Opening a local HTML file in Chrome or Safari works for a quick look, but the tab has no home-screen presence, loses state, gets throttled in the background and cannot ring an alarm when the phone is locked. "Add to Home Screen" (PWA) gives you an icon, but still no exact alarms on iOS and unreliable background behaviour on Android.

Three ways, compared

Steps

1. Get Kapsula from Google Play or the App Store.
2. Tap Add project. Paste the HTML (for example from a ChatGPT or Claude answer), choose an .html file, or enter a URL.
3. Tap Run. The page now lives in your project list with its own name, storage and notification channel.
4. Optional: use the bridge API — kapsula.notify.schedule() for alarms, kapsula.storage for state — and your page behaves like a native app. See the gallery for ready examples.

Limits to know

Single-file pages work best: the sandbox blocks requests to outside servers for now, and browser storage (localStorage) doesn't persist — use kapsula.storage. Up to 16 pending alarms per project. Free plan: one project of your own plus the built-in demo.

FAQ

Can I run an HTML file as an app on iPhone without Xcode?

Yes. Kapsula on the App Store runs your single HTML file as a project; no Xcode, no developer account.

Does the HTML app work offline?

Yes. Pasted-code and file projects need no network at all.

Do I need to publish it to an app store?

No. The file stays on your phone; nothing is uploaded anywhere.