# Deep link validator for Android and iOS

Source: https://saastostore.com/tools/deep-link-validator

Enter your domain to check the two files that make links open your app: `assetlinks.json` for Android and `apple-app-site-association` for iOS. The check is free and needs no account. We fetch both files from your site, the way a phone would.

## What it checks

| Check | Android | iOS |
| --- | --- | --- |
| Found at the right address, with no redirect | Yes | Yes, at both accepted addresses |
| Served as `application/json` | Yes | Yes |
| Valid structure | Array with the right relation | `applinks.details` is filled in |
| App identity | `package_name`, SHA-256 format | `appID` or `appIDs`, format |
| Pages covered | Not applicable | `paths` or `components` is present |

## What it can't check

- Whether the fingerprint is the one of your published app. Only you can compare it with your project page and the Play Console.
- Whether the Apple team is the one that signed your app. A wrong one looks valid and fails in silence.
- Apple's own copy of your file. iOS reads it through Apple's servers, which can lag behind.

## Fix what it finds

- **HTTP 404:** the file isn't at that exact address. See [how to host the files](https://saastostore.com/docs/deep-links#hosting).
- **A redirect:** often `example.com` to `www.example.com`. Each domain must serve the file directly.
- **A wrong type:** set `application/json` in your server or hosting settings.
- **A wrong format:** download the file again from your project page rather than editing it by hand.

For the whole setup, read [Deep links: open your app from a link](https://saastostore.com/docs/deep-links).

## Frequently asked questions

### Do you store the domain I enter?

The check fetches the two public files and returns a verdict. We don't save the result.

### Do these files work with apps not made with SaasToStore?

Yes. They're Google and Apple standards, so you can use this tool for any app.

### Everything passes but links still open the browser. Why?

Reinstall the app, then tap a link from another app. Then compare the fingerprint or the Apple team with those of the installed build.