How do I run an HTML file as an app on Android or iPhone?

Install Kapsula, tap “Add project”, then paste the code, pick the .html file or enter a URL. The page opens as a project with its own storage and alarms.

Can a web page set an alarm that fires when the app is closed?

In a browser — no. In Kapsula — yes: kapsula.notify.schedule() creates a real system alarm that the OS delivers even if the app was killed.

Both. Kapsula is on Google Play and the App Store, and the same HTML file works on either.

Do you see my code or my data?

No. There is no Kapsula server. Everything stays on your phone — see the privacy policy.

Single-file pages work best. The page runs in a sandbox, so requests to outside servers are blocked for now.

Yes. Free includes one project of your own plus the demo; Kapsula Pro with unlimited projects is coming later.

Kapsula

Turn ChatGPT code into a real phone app.

Kapsula is a free app for Android and iOS that runs a single HTML file as a real app. Paste code from ChatGPT or Claude, drop an .html file, or point at a URL — your page gets exact alarms, sound, vibration and storage. No Android Studio, no account, no cloud.

GET IT ONGoogle Play DOWNLOAD ON THEApp Store See how it works

Android & iOS · free · no account · no cloud · works offline · 13 languages

09:41▲ ▂▄▆ ▮

Kapsula

Shift 45/45demo · alarms on

Water trackerpaused

+ Add project

tea.htmlRun ▸

🍵

03:00

Start

kapsula.notify.schedule()

09:44

Friday, August 28

K Kapsula · now

Tea is ready 🍵

Even though the app is closed.

paste code from an AI chat → a real app

How it works

Get the code

Ask ChatGPT or Claude for a single-file HTML tool — a timer, a routine, a tracker. Or write it yourself. There is a ready-made prompt.

Drop it into Kapsula

Paste the code, pick the file, or give a URL. It becomes a project in your list — with its own name, storage and notification channel.

It behaves like an app

Your page can schedule real OS alarms. They fire on time even if the app is closed or swiped away — something a browser tab can never do.

What your code gets

Exact alarms

kapsula.notify.schedule()
Second-accurate, survive the app being killed.

Storage

kapsula.storage.get/set
Per project, stays after you update the code.

Sound & vibration

kapsula.sound.play() · kapsula.haptics

A sandbox, not your phone

Code runs isolated. It only gets what the bridge gives it — nothing else on the device.

The same file works in a browser and in Kapsula:

// alarm in 25 minutes — the OS remembers it, not the page
if (window.kapsula) {
  await kapsula.notify.schedule({
    at: Date.now() + 25*60*1000,
    title: 'Break time',
    body: 'Stand up, look away from the screen'
  });
}

Full bridge API reference →

Why not just a browser tab

Alarms actually fire. A background tab gets throttled and killed; an OS alarm doesn't.
Opens where you left it. State lives in the project's storage, not in a tab that may be gone tomorrow.
No server, no sign-up. The code and its data live on your device.
Not a website builder. Kapsula doesn't host or generate anything — it runs what you already have.

Status

Kapsula 0.1 is out on Google Play and the App Store. Version 0.2 with 13 interface languages is in review. Questions, bugs, ideas — hello@kapsula.app.

Free plan: one project of your own, plus the built-in demo. Unlimited projects will come with Kapsula Pro.

FAQ

How do I run an HTML file as an app on Android or iPhone?: Install Kapsula, tap “Add project”, then paste the code, pick the .html file or enter a URL. The page opens as a project with its own storage and alarms.
Can a web page set an alarm that fires when the app is closed?: In a browser — no. In Kapsula — yes: kapsula.notify.schedule() creates a real system alarm that the OS delivers even if the app was killed.
Android or iPhone?: Both. Kapsula is on Google Play and the App Store, and the same HTML file works on either.
Do you see my code or my data?: No. There is no Kapsula server. Everything stays on your phone — see the privacy policy.
Can it run any HTML?: Single-file pages work best. The page runs in a sandbox, so requests to outside servers are blocked for now.
Is it free?: Yes. Free includes one project of your own plus the demo; Kapsula Pro with unlimited projects is coming later.