This page provides an overview of the tagging options you can use to measure activity on your site and send the data to Google Analytics. The Google tag is designed for measurement across many Google products, including Google Ads. We recommend using Tag Manager to get started.
For details on the Google tag, Tag Manager and gtag.js products, see the Tag platform documentation.
The Google tag
The Google tag is a single tag you can add to your website to measure organic and ad performance. You can configure a Google tag for Google Analytics, and send the data from that tag to other products, like Google Ads, by adding destinations to your tag.
To send data from a Google tag to your Google Analytics account, you need to accept the Google Analytics Terms of Service (ToS).
To get started with the Google tag for Google Analytics, we recommend using Google Tag Manager.
Google Tag Manager
Google Tag Manager is a web-based tag management system, that lets you create Google tags and install them on your website, without manually adding JavaScript snippets to your site. You can also update the settings for tags that are already in use on your site in Tag Manager, without needing to re-deploy your site each time.
Google Tag Manager supports the Google tag you need for Google Analytics, a wide array of third-party tags, and even custom tags.
Set up and install Tag Manager
gtag.js
If you already use Google Tag Manager, you don't need to use gtag.js.
gtag.js is a JavaScript framework you can use to add Google tags to web pages. To use gtag.js effectively, you need to be proficient in HTML, CSS, and JavaScript.
You can migrate your tags to Google Tag Manager from gtag.js if needed.
gtag.js cookie usage
For the latest information on cookie usage in Google Analytics, see Cookie usage on websites.
The gtag.js JavaScript library uses first-party cookies to do the following:
- Distinguish unique users.
- Distinguish sessions for a user.
When using the recommended JavaScript snippet, cookies are set at the highest
possible domain level. For example, if your website address is
blog.example.co.uk, gtag.js sets the cookie domain to .example.co.uk.
Setting cookies on the highest level domain possible lets measurement occur
across subdomains without extra configuration.
gtag.js sets the following cookies:
| Cookie name | Default expiration time | Description |
|---|---|---|
_ga |
2 years | Used to distinguish users. |
_ga_<container-id> |
2 years | Used to persist session state. |
Customization
To learn how you can customize the default cookie settings using gtag.js, see Cookies and user identification guide.
Google Tag Manager versus gtag.js
Here's an overview of the differences between gtag.js and Tag Manager for Google Analytics.
The following table highlights the differences between gtag.js and Tag Manager for Google Analytics.
|
|
Google Tag Manager (Tag Management System) |
|---|---|
|
You need to write code to deploy tags and customize your web collection |
Deploy and modify both tags from Google and third-parties on the fly without editing code. |
|
Can only send data for Google products. |
Can send data for Google tags, third party tags, and custom tags. |
|
You need to manage your tags from within your code, and may need to duplicate code for different outlets, for example, web and app. |
Manage tags for your website and apps all from tagmanager.google.com |
|
Version control depends on how you manage your code. |
Collaborate with others using workspaces, and version control tags. |
|
Server-side tagging is possible. You still need to use Google Tag Manager to deploy and interact with your server container. |
Tag Manager helps you deploy tags on a server. If you are exploring this option, read Client-side and server-side tagging. |
|
Compatible with static-site generators, CMSs, website builders or manually authored HTML pages that support JavaScript. |
Compatible with many CMSs and website builders. If your system doesn't
support Tag Manager, use the Google tag ( |
|
Cost: Free |
Cost: Free |