Google Tag Manager (GTM) is helpful for code tracking purposes, but does it slow down your website? If you’re unfamiliar with the best practices of GTM performance optimization, it can negatively impact your site performance.
In this article, I will share nine tips to optimize your GTM setup and enhance your website’s speed, ensuring a seamless and efficient user experience.
Let’s begin!
9 GTM Tips for Faster Site Speed
We don’t have to tell you that website speed is paramount for providing an optimal user experience and improving search engine rankings. Google Tag Manager offers a plethora of features that can be harnessed to enhance website performance.
Let’s go through 9 essential GTM optimization tips that can significantly reduce load times and make your site run more efficiently.
1) Minimize the Number of Tags
One of the key factors in improving website speed with Google Tag Manager is to minimize the number of tags. Each tag added to your site comes with its own code and resources, which can contribute to increased page load times.
By carefully reviewing your tag inventory and removing any unnecessary or redundant tags, you can significantly reduce the overall weight of your website and improve its speed.
To minimize the number of tags:
- Start by conducting a thorough audit of your GTM container.
- Identify tags that are no longer needed or serve redundant purposes.
- Consider if any tags can be consolidated or combined into a single tag to reduce the number of network requests.
By streamlining your tag implementation and keeping only the essential tags, you can create a lean and efficient GTM setup that optimizes website performance. Remember, fewer tags mean faster load times and a smoother user experience.
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2) Optimize Tag Firing Triggers
In Google Tag Manager, tags are activated based on a custom event like page loads or clicks. Reviewing and optimizing your tag-firing triggers is important to ensure they are set up efficiently.
Some of the top trigger types are page view triggers, click triggers, custom event triggers, history change triggers, and JavaScript error triggers.
Tag Firing Options
You can find the tag firing options in the Advanced Settings of any tag definition within a web container. Here are the three tag firing options:
- Unlimited: This option is used in conjunction with tag sequencing. Tags will fire whenever triggers indicate they should, without any limitations.
- Once per event: With this option, the tag will fire only once when a specific event occurs.
- Once per page: With this option, the tag will fire just once when the page loads.
Creating a Trigger
You can create a GTM trigger by following the below steps:
- Click Tags > New.
- Click Trigger Configuration.
- Select the trigger type you would like to create.
- Complete the setup for your selected trigger.
3) Utilize Tag Sequencing
GTM tags that have dependencies on one another can affect the speed of your website if they are not sequenced properly.
The good news is that GTM provides a convenient tag sequencing feature that allows you to control the order in which these dependent tags are executed.
With tag sequencing, you can specify tags to be fired immediately before or after a designated “primary” tag. This functionality is available within web containers and can be applied to any tag configuration from Advanced Settings > Tag Sequencing options.

4) Enable Built-in Variables
Google Tag Manager offers a range of built-in variables that provide valuable data without the need for additional tags. These variables allow you to access important information about the user’s browsing context and the website itself.
For instance, the {{Page URL}} variable provides the URL of the current page being viewed. This can be useful for tracking specific pages, analyzing user behavior, or passing the page URL as a parameter to other tags.
Similarly, the {{Referrer}} variable captures the URL of the referring source, which indicates the previous page or source that directed the user to the current page.

For example, if you want to track the page URL and pass it as a parameter to a specific tag, instead of manually extracting it using JavaScript libraries, you can utilize the built-in variable {{Page URL}} provided by GTM.
Using the {{Page URL}} built-in variable eliminates the need to write JavaScript code to extract the page URL manually.
You should use these variables whenever possible as they eliminate the need for extra tags, reducing the overall number on your website.
5) Implement Content Security Policy (CSP)
Content Security Policy is a security mechanism implemented on web servers to protect websites from various security threats.
By implementing a well-defined CSP, you establish a robust barrier that prevents unnecessary third party scripts from loading onto your website. This enhances your website’s security and can positively impact performance.
By reducing the risk of malicious external scripts and unauthorized code, your website can operate more efficiently, resulting in improved speed and a safer user browsing experience.
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6) Avoid Heavy DOM Manipulations (As a Long-Term Solution)
DOM manipulation involves making changes to the structure or content of a web page using JavaScript. While it can be helpful in certain dynamic functionalities, excessive manipulation can cause delays in rendering and affect overall website performance.
Consider whether alternative approaches will achieve the same goal. This might involve utilizing other native browser features or working with your development team to find optimized solutions.
Collaborating with your development team is valuable for implementing long-term strategies to improve website speed. They can help identify areas where heavy DOM manipulation occurs and suggest alternative techniques or optimizations.
7) Explore Server-Side Tagging with Google Tag Manager
Consider implementing server-side tagging with Google Tag Manager, particularly for tags that do not require client-side execution. This implementation can have a substantial positive impact on website performance.
The below figure depicts the working of server side tracking with GTM:

This offloads the processing of tags from the user’s device to a server, which has more resources and can handle the tasks more efficiently. The website can load faster by minimizing the amount of JavaScript code running on the client side, improving performance.
When deciding to implement server-side tagging with GTM, it is essential to identify the tags that do not rely on client-side interaction or user-specific data. These tags, such as those related to internal analytics or server-side events, can be seamlessly transitioned to the server side.
8) Always Keep Your Google Tag Manager Container Lean
Unused tags, variables, or triggers that linger in your GTM container contribute to unnecessary processing and can slow down your website. By taking the time to review your container regularly, you can identify and eliminate these unnecessary components. This maintenance ensures that only essential elements are present, streamlining the overall operation of your GTM setup.
Regular maintenance of your GTM account should be an ongoing practice. Set aside time periodically to assess and clean up any unused or redundant items. This proactive approach helps ensure that your GTM implementation remains efficient, up-to-date, and aligned with your website’s needs.
9) Use a Caching Proxy to Load GTM
Using a caching proxy to load Google Tag Manager involves utilizing a server-side caching mechanism to improve the delivery and loading of GTM resources on a website. When a user visits a webpage with GTM implemented, their browser sends a request to fetch the GTM container and its associated scripts from the server.
However, this process can introduce latency and affect initial page load times, especially if the server is geographically distant or experiencing high traffic. A caching proxy can be implemented between the user’s browser and the GTM server to mitigate these issues. The caching proxy acts as an intermediary, intercepting requests for GTM resources and serving cached versions of those resources instead of fetching them from the GTM server every time.
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Google Tag Manager Performance Optimization Tips
Here’s a quick chart of all the GTM optimization tips we covered here:
Last Word on Google Tag Manager and Website Performance
Google Tag Manager offers a convenient solution for managing multiple tags and tracking codes, but optimizing its implementation is crucial to maximize website performance. Take appropriate time to fine-tune your GTM setup, and reap the rewards of a faster, more efficient website!
If you’re ready to optimize your GTM setup, Single Grain’s Google Tag Manager experts can help!👇
Google Tag Manager Performance Optimization FAQs
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Does GTM Slow Down My Website?
Google Tag Manager does not inherently slow down your website. However, if improperly configured or too many tags are added, it can impact your website’s performance.
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How Can I Improve the Page Speed of My Website?
Start by using fewer tags in Google Tag Manager and optimizing tag-firing triggers. Utilize GTM’s tag sequencing feature and enable built-in variables to streamline the operation. Implement Content Security Policy to enhance security and prevent unnecessary script execution.
Avoid heavy DOM manipulations, explore server-side tagging with GTM, keep your GTM container lean, and consider using a caching proxy to load GTM resources.
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How Do GTM’s Custom JavaScript Variables Impact Page Performance?
Custom JavaScript variables in GTM significantly impact page performance depending on how they are implemented. Poorly optimized or complex JavaScript code within custom variables can slow the page load. It’s important to carefully review and optimize custom JavaScript variables to ensure they execute efficiently and do not have a negative performance impact.
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Can Using Custom HTML Tags Impact GTM Performance?
Yes, using too many HTML codes can negatively impact performance. Avoid using too many marketing tags. Also, you should use a custom HTML tag that is optimized, efficient, and does not introduce unnecessary complexity or delays.
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What Is the Role of Google Analytics Tags in GTM and How Do They Affect Website’s Performance?
A Google Analytics tag in GTM collects and sends data to the GA platform. These universal analytics tags are crucial for tracking and analyzing user interactions, conversions, and other important metrics on your website. When implemented and configured correctly, Google Analytics tags in GTM can provide valuable insights.
However, improper tag configuration, excessive use of tags, or inefficient firing rules can cause performance issues, leading to slower page load times and potential disruptions to the user experience.
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How Can I Ensure That GTM Tags Are Firing in the Desired Order?
GTM offers the tag sequencing feature that allows you to specify the order of tag fires. By configuring to fire tags before or after a primary tag, you can ensure they execute in the desired sequence, considering dependencies or specific order requirements.
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Are There Any Tools or Techniques to Measure the Impact of GTM on Website Performance?
Yes, there are various tools and techniques to measure the impact of GTM on website performance. Performance monitoring tools like Google Lighthouse, PageSpeed Insights, or web browser developer tools (e.g., Chrome DevTools) can help evaluate page load times, network requests and identify potential bottlenecks caused by GTM or other factors.
Additionally, conducting manual testing and comparing page load times with and without GTM can provide insights into its impact on performance. Leverage these tools and apply minor improvements to boost your marketing efforts.
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Is Google Tag Manager Good for SEO?
Google Tag Manager itself does not have a direct impact on SEO. However, it can benefit SEO efforts by providing a centralized platform for managing various tracking codes and tags. It allows for easy implementation of tracking and analytics tools, which can provide valuable data for SEO analysis and optimization.
Additionally, GTM’s flexibility and ease of use can streamline adding and managing SEO-related tags, making it a valuable tool in an SEO strategy.
If you were unable to find the answer you’ve been looking for, do not hesitate to get in touch and ask us directly.