The Google tag and Tag Manager

This document is for people who are new to tagging and want to know what tagging setup is the best for them.

This document provides an overview of the Google tag (gtag.js) and Tag Manager. If you are setting up Google Analytics on an app, also see the Firebase documentation.


The Google tag is a single tag you can add to your website to measure website and ads performance. The Google tag is needed to send data to Google Ads and Google Analytics 4 (GA4), also called destinations.

What tagging option is best for me? 

You can either use the Google tag on its own or use the Google tag with Tag Manager.

This article explains the different tagging options so you can choose the option that fits your needs.

When to only use the Google tag?

The Google tag is the basis for all measurement use cases. If you currently use Google Ads or GA4, the product auto-generates a Google tag for you. The next step is to update your website code.

The Google tag lets you:

  • Use a single Google tag across your entire website instead of managing multiple tags for different Google product accounts.
  • Automatically measure page views, clicks, scrolls, and more in Google Analytics. Learn more
  • Automatically measure conversions and campaign performance in Google Ads. Learn more
  • Configure these Google tag settings from within your Google products (e.g. Google Ads, Google Analytics, Google Tag Manager), minimizing the need to make code changes to your site.

This tagging option is great for marketers who don't have a web development team readily available or use a content management system (CMS). If you only need the default metrics, such as page views, clicks and scrolls, you can set up the Google tag once and you're all set.

Ready to get started?

Need more control?

Consider adding one of the following tagging options to your Google tag:

  • Google Tag Manager (recommended)
  • gtag.js

What is gtag.js?

The Google tag uses the gtag.js JavaScript framework to add Google tags directly to web pages. To use gtag.js effectively, you need to be proficient in HTML, CSS, and JavaScript.

This tagging option is best for web developers who are in charge of tagging and only need to manage Google tags. gtag.js lets you install tags directly on your web page, without the ramp-up time of setting up a tag management system.

If your tagging needs evolve, you can always migrate your tags to Google Tag Manager at a later date.

What is Google Tag Manager?

Tag Manager is a tag management system that allows you to quickly and easily update tags on your website or mobile app from a web interface. You can use Google Tag Manager to load a Google tag on your website. This method is equal to adding the Google tag code snippet to your site.

Tag Manager supports Google-specific tags, a wide array of third-party tags, and even custom tags. See all supported tags.

This option is best for marketers who are in charge of tagging and need to manage Google and tags from other parties. It's also a good option for tag administrators, and agencies and can be used in conjunction with site code changes.

Google Tag Manager and gtag.js comparison

The following table highlights the differences between Tag Manager and gtag.js.

gtag.js (code deployment)

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.
See all supported tags

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

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 allows you to easily 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 (gtag.js) instead.

Cost: Free

Cost: Free

Ready to use Google Tag Manager?

Set up and install Tag Manager →

If you already use Tag Manager, continue to do so. Tag Manager fully supports Google Ads and Google Marketing Platform tags, and there is no need to deploy additional code using gtag.js on your site if Tag Manager is already in use.

Next steps