Скачать или смотреть What is Google Tag Manager and why need to use it ? | Marf Digital

A Tag Manager is a free tool from Google that acts like a "toolbox" or a central container for all the little snippets of code (called "tags" or "pixels") you need to put on your website.
Think about all the different services you might use:
Google Analytics to see your traffic.
Google Ads to track conversions.
Facebook Pixel for remarketing.
Heatmap tools like Hotjar.
Each of these services gives you a piece of JavaScript code to add to your website's pages.
Why use a Tag Manager instead of adding them all directly to your site?
Speed and Agility: Marketers can add, update, or remove tags themselves through the GTM interface. You don't have to wait for a developer to manually edit the website's code, which can save a lot of time and let you launch campaigns faster.
Centralized Management: All your tracking tags are organized in one dashboard. This makes it easy to see what's running on your site, who added it, and when it was last updated.
Improved Website Performance: Instead of having many different code snippets slowing down your site, you just have one GTM snippet. GTM loads these tags asynchronously, meaning it doesn't stop your page from loading while it works in the background.
Error Reduction: GTM has a built-in "Preview Mode" that lets you test your changes on your own computer before you publish them to your live website. This helps you catch mistakes before your users do.
Simplicity: Once the main GTM code is installed, most future tracking can be set up with just a few clicks, without ever touching the website's code again.