# Install with Google Tag Manager

> Add Datacenter through Google Tag Manager with a Custom HTML tag on all pages. Use this if Tag Manager is already on your site.

Source: https://datacenter.so/docs/install-google-tag-manager
Section: Start here

If Google Tag Manager is already on your site, you can add Datacenter there. It takes about five minutes.

## Before you start

Copy your tag. In Datacenter, open [Set up your site](https://app.datacenter.so/start), or open your site's **Settings**. Your tag looks like this, with your own address:

```html
<script defer data-site="yoursite.com" src="https://datacenter.so/s.js"></script>
```

## Steps

1. In Tag Manager, open your container. Click **Tags**, then **New**.
2. Name it Datacenter. Click **Tag Configuration** and pick **Custom HTML**.
3. Paste the tag into the **HTML** box.
4. Under **Triggering**, pick **Initialization - All Pages**. Click **Save**.
5. Click **Submit**, then **Publish**.

## Check it works

Tag Manager adds tags after the page loads, so the **Check my site** button cannot see them. Open your site in a new tab instead. On the last setup step in Datacenter, your first visit shows up in a minute or two.

## Good to know

- Nothing is counted until you publish the container.
- If your site has no Tag Manager yet, it is simpler to paste the tag straight into your site. See [Install on any site](https://datacenter.so/docs/install-html).