Why do marketers confuse Google Tag Manager and Google Analytics?
To clear the air let me draw your attention to the fact that Google Analytics is the tracking tool, while Google tag manager is the mediator between your website and tracking tool. Google Analytics collects, stores, and analyses data while Google Tag Manager sends the data from your website to Google Analytics or other tools in the form of tags.
They are both Google products and they’re both free. But the confusion extremely lies within the implementation of Google Analytics. As many marketers install Google analytics through Google tag manager, you can also install Google analytics directly.
If Google Analytics is your only tracking tool, it makes excellent sense to put the code directly on your website. You only need to fuse with one interface, and the configuration is very simple. But if you’re using multiple tracking tools you can install Google tag manager on your website, they connect your Google tag manager account to your Google Analytics account.
The setup is a little exhausting, but it gives you more advanced tracking options and is more flexible with multiple tools.
So you can have both of them installed but this would result in poor implementation and erroneous data.
The main reason you would go with Tag Manager is if you plan to use other tool tags like Facebook Pixel, and Google ads in the future, and also it allows you to add many tags to your website in an organized way.
Are there alternatives to both of them? There are so many but the problem is they are not free and it may take a lot of time to train the entire team about the tools they are not familiar with.
So if we compare both of them:
• Google tag manager does not replace Google analytics instead it helps users to add Google Analytics tracking codes to their websites.
• Google tag manager and Google analytics are both independent of one another. Developers can hard-code Google analytics codes directly to the website but if you constantly need to publish changes only developers can help you. But with Google tag manager you can add, edit, and remove your Google Analytics tracking codes all by yourself

• Google Analytics supports only some Google products like gtaj.s while Google tag manager supports way more platforms not only Google tools like a hot jar, Microsoft ads conversion tracking, and more.
• Google tag manager events are used as triggering conditions that define where a certain must be fired. Google Analytics in this context is a tag.
(Trigger: they are a way to fire the tags you set up, they tell the tag manager when, where, or how to do what you want it to do. Pageviews, Links Clicks, Form Submissions. Scroll Depth, Custom Events are some examples
Tags: they are snippets of code or tracking pixels from third-party tools. They tell Google tag manager what to do. Google Analytics universal tracking code, Adwords remarketing code, Adwords Conversion Tracking Code, Heatmap tracking code. Custom HTML scripts, Cookiebot, and other GDPR data privacy scripts are some examples)
• You cannot create Google analytics goals and conversions in Google tag manager. Google tag manager sends events to Google analytics. Goals and conversions are then configured inside of Google analytics where you instruct Google Analytics to turn some regular interactions into more valuable goals
You could install your Google Analytics through Google tag manager if you also use other tags like the Facebook pixel or adobe analytics tag.
BUT AS A REMINDER USE ONE IMPLEMENTATION OR THE OTHER –not both
Eventually, Google tag manager acts as a middleman between the implementation on your website and Google Analytics, where the data gets sent
I would recommend using both tools because they are both free and they can help your business in different ways but personally Google tag manager is a more powerful and flexible option as it does not restrict only to Google products