# Install the browser extension (/docs/using/setup/browser-extension)

The WriteStack extension connects WriteStack to Substack through your browser. You need it to schedule Notes on Substack, post them and sync stats. Install it on a computer from [writestack.io/extension](https://writestack.io/extension), which opens the right store for your browser.

## Steps [#steps]

1. On a computer, open [writestack.io/extension](https://writestack.io/extension).
   - Chrome and other Chromium browsers: [Chrome Web Store](https://chromewebstore.google.com/detail/writestack/emdlbnkhjpfcooclfbodmhkhkohcjaoa)
   - Firefox: [Firefox Add-ons](https://addons.mozilla.org/en-US/firefox/addon/writestack/)
2. Click **Add to Chrome** (or **Add to Firefox**) and accept the permissions.
3. Make sure you're logged in to Substack in the same browser.
4. Go back to WriteStack and refresh the page. During onboarding, click **I have installed the extension** instead.

If WriteStack needs the extension and can't find it, you'll see a **Chrome Extension Required** (or **Firefox Extension Required**) dialog. Click **Install the extension**, then **(Refresh after installation)**.

## What it does [#what-it-does]

The extension runs Substack actions from your own browser, using your Substack login. It is used for:

- Scheduling Notes on Substack. With the extension installed, **Add to Queue** creates the scheduled Note on Substack right away. Once a Note is on Substack, Substack publishes it itself, so your browser doesn't need to be open at send time. See [Sync](/docs/using/concepts/sync).
- Syncing Notes that were scheduled without it (from your phone or an AI assistant, for example).
- Posting Notes now, uploading images, videos and link previews, and adding polls.
- Fetching your Notes stats.
- Actions in the Activity Center, Chats and DMs, such as replies and likes.

## Supported browsers [#supported-browsers]

| Browser | Supported |
| --- | --- |
| Chrome | Yes |
| Brave, Edge, Opera, Arc and other Chromium browsers | Yes, from the Chrome Web Store |
| Firefox (version 140 or newer) | Yes |
| Safari | No |
| Phones and tablets | No. You can use WriteStack on your phone, but scheduled Notes wait in WriteStack until you sync them from a computer. |

## Minimum versions [#minimum-versions]

Some features need a recent version of the extension. If yours is older, the feature is hidden or you see a message such as "You need to have the extension version 1.5.15 installed to add polls".

| Feature | Minimum extension version |
| --- | --- |
| Videos in Notes | 1.4.23 |
| Scheduling Notes on Substack | 1.4.68 |
| Auto-restack | 1.4.77 |
| Welcome DMs | 1.5.8 |
| Polls in Notes | 1.5.15 |
| Video covers | 1.5.21 |

Chrome and Firefox keep the extension up to date on their own. To see which version you have, open `chrome://extensions` (or `about:addons` in Firefox) and find **WriteStack**.


## Custom domains [#custom-domains]

If your newsletter uses a custom domain, some features ask the extension for access to that domain. Click **Grant access** (or **Allow access to** your domain) when WriteStack asks, and accept the browser prompt.

## If it doesn't work [#if-it-doesnt-work]

See [Sync errors](/docs/using/troubleshooting/sync-errors) and [Substack connection problems](/docs/using/troubleshooting/substack-connection).