# Inspecting web app manifests

In this article we will look at inspecting [app manifests](https://developer.mozilla.org/en-US/docs/Web/Manifest) using the Firefox DevTools {doc}`Application panel <../index>`.

When you open the Application panel’s *Manifest* view on a page that doesn't have an app manifest successfully deployed, you'll get the following output shown:

```{image} no-manifest.jpg
:alt: default manifest view saying that you need to add a manifest to inspect it.
:class: border
```

## Deploying a manifest

To get a manifest deployed successfully, you need to include a [\<link>](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/link) element in the [\<head>](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/head) of your document that points to your `.webmanifest` file:

```html
<link rel="manifest" href="/manifest.webmanifest">
```

The `.webmanifest` extension is recommended in the spec, and should be served with an `application/manifest+json` mime type, although browsers generally tend to support manifests with other appropriate extensions like `.json` (mime type: `application/json`).

You also need to make sure the JSON inside the file is of the correct format.

## Inspecting your manifest

If your manifest is deployed successfully, you should end up with a display like the following on the *Manifest* view:

```{image} manifest-deployed.jpg
:alt: manifest view showing a deployed manifest, with identity, presentation, and icon
:  information shown
:class: border
```

From here, you can inspect all the information in the manifest in an easy-to-digest way, making sure that it is all correct. It provides a link to the manifest file at the top which when clicked on brings up the JSON in a new tab.

It also loads all the icon files into the view, so you can see the relative size of them all, and any other information associated with them.

## List of manifest members

We won't provide an exhaustive list of all the members that can appear in a web manifest here; you can already find that in our [web manifest documentation](https://developer.mozilla.org/en-US/docs/Web/Manifest#members).
