Creating a Compliant Cookie Consent Banner for SvelteKit and GTM

· 32 min read

Table of Contents


    With regulations such as GDPR and CCPA setting the standard, website owners are compelled to ensure that visitors' consent is obtained before any cookies are used that track personal information.

    For those unfamiliar, SvelteKit is an application framework built on top of the innovative Svelte library, offering enhanced capabilities for building dynamic and reactive web applications. Google Tag Manager (GTM), on the other hand, is a powerful tag management solution that simplifies deployment and management of tracking codes and related analytics scripts.

    Find out more about SvelteKit

    We have created a full guide on understanding the basics, setting up your first project and moving on towards some advanced aspects of this powerful framework.

    When it comes to integrating a cookie consent banner into SvelteKit applications, developers must navigate a solution that is not only responsive and non-intrusive but also adheres to the stringent guidelines of data protection laws.

    The implementation of a cookie consent banner in SvelteKit, coupled with the analytics insights afforded by GTM, presents unique challenges. The consent banner should be customizable to reflect the specific categories of cookies used by a website, providing clear options for users to give or withdraw consent. Moreover, it needs to integrate seamlessly with GTM to ensure that tags are fired only after obtaining the necessary permissions, thereby remaining compliant while tracking valuable user interactions effectively.

    Whether you're a web developer seeking a technical implementation guide, a SvelteKit enthusiast looking for best practices, or a digital marketer aiming to align your strategies with legal standards, understanding how to craft a compliant cookie consent banner is essential. In the following sections, we will explore practical steps, recommended libraries, and the nuances of integrating consent banners with SvelteKit and GTM, ensuring that you can uphold user trust and meet the requirements of the digital age.

    At the heart of any discussion on cookie consent banners lies the pivotal question: why are they necessary? To comprehend the gravity of cookie consent, one must consider the legal frameworks that govern online privacy—GDPR in the European Union, CCPA in California, and other regional legislations worldwide.

    GDPR, or the General Data Protection Regulation, revolutionized privacy standards by enforcing the principle of informed consent. Under GDPR, cookies that identify an individual directly or indirectly are considered personal data. This regulation mandates that before such cookies are placed on a user's device, clear and explicit consent must be obtained, save for those strictly necessary for the function of the website.

    Similarly, CCPA, or the California Consumer Privacy Act, empowers Californians with the right to know what personal information is collected about them, denying or approving the sale of this information. While not as stringent as GDPR when it comes to cookies, it still necessitates a level of transparency and user control over their personal data.

    Failure to comply with these regulations not only risks hefty fines but can also damage brand reputation and user trust—critical aspects in a digitally connected world. Users are now more aware of their data rights, and their confidence in a platform often hinges on how well it respects and protects their privacy.

    With these regulations in place, a cookie consent banner acts as the first line of communication between a website and its user—informing them about the type of cookies used, their purposes, and seeking their agreement to proceed. It's an interaction that must be clear, unambiguous, and documented as evidence of consent. This consent must also be as easy to withdraw as it is to give, offering users control over their data after their initial decision.

    This level of granularity in user consent puts a spotlight on GTM's functionality. GTM integrations must be crafted such that analytical and marketing tags are triggered only if the user consents to the respective cookie categories. Without such consent, GTM should remain inactive, ensuring no personal data is processed unlawfully.

    A well-implemented cookie consent mechanism within SvelteKit applications not only meets legal obligations but is also a testament to a business’s commitment to transparency and user-centric values. It's a delicate balance between compliance and usability—one that can be achieved with the right tools and guidance.

    When faced with the task of incorporating a cookie consent banner into a SvelteKit application, developers have a bevy of libraries and plugins at their disposal. However, choosing one that aligns with both the technical architecture of SvelteKit and the legal intricacies of privacy regulations is paramount.

    To begin with, it's worth exploring the @beyonk/gdpr-cookie-consent-banner which stands out for its Svelte/Kit compatibility. This banner is GDPR compliant and is renowned for its simplicity and customization options. With this library, developers can craft a consent banner that not only adheres to the requisite legal standards but also complements the overall design of the website. From a technical standpoint, it is easily integrated into the SvelteKit project through NPM or a CDN, facilitating quick deployment.

    Another noteworthy option is the sveltekit-cookie-manager, a package tailored specifically for SvelteKit that assists in controlling visitors' cookie consent. This plugin offers a customizable popup to accept or reject cookies, a feature crucial for ensuring that users are informed about their choices in a clear and concise manner.

    While choosing a library, it is important to consider the user experience. A consent banner that disrupts the user's journey with cumbersome interfaces or convoluted language is likely to drive visitors away. The chosen solution should offer clarity and ease-of-use, allowing users to make informed decisions without feeling overwhelmed.

    Interoperability with GTM is also an important consideration. The selected library should have the capability to work in tandem with GTM to trigger tags based on the user's consent status. This ensures that your website remains compliant, while still benefiting from the rich analytics insights GTM provides.

    It is also advisable to seek libraries that support asynchronous loading. By doing so, you prevent any potential impact on your website’s performance and loading speeds—a critical factor in user retention and SEO performance.

    Developers must ensure that the implementation of the cookie consent library is in sync with SvelteKit's server-side rendering and hydration processes. The library's ability to maintain state across both client and server will guarantee a consistent experience regardless of the entry point.

    Lastly, take a moment to verify the ongoing support and maintenance of the library. A library with active maintenance and a vibrant community can be a goldmine of resources and support, ensuring that any issues encountered during development or deployment can be swiftly addressed.

    In summary, selecting the right cookie consent library for your SvelteKit application involves a careful evaluation of compatibility, user experience, compliance with legal standards, and concerted integration with GTM. Once the right tool is selected, developers can then focus their energy on creating engaging user experiences, safe in the knowledge that their privacy mechanisms are robust and fully compliant.

    Integrating a cookie consent banner into a SvelteKit application requires a systematic approach. Adhering to a step-by-step process will ensure that both the compliance and user experience aspects are properly addressed. Let's walk through the integration process.

    Step 1: Choose Your Consent Banner Library

    After evaluating options such as the @beyonk/gdpr-cookie-consent-banner or sveltekit-cookie-manager, select the library that best fits your requirements. Consider aspects like GDPR compliance, ease of customization, and GTM compatibility.

    Step 2: Install the Library

    Using your terminal, navigate to your project directory and install your chosen cookie consent library using npm or yarn. If you opt for `@beyonk/gdpr-cookie-consent-banner`, the command will be as follows:

    npm install --save-dev @beyonk/gdpr-cookie-consent-banner


    yarn add @beyonk/gdpr-cookie-consent-banner

    Step 3: Add the Banner Component to Your Project

    Import the consent banner component at the top level of your application, typically in your `__layout.svelte` file, to ensure it renders on every page. Insert the component into the markup as directed by the library's documentation.

    import CookieConsent from '@beyonk/gdpr-cookie-consent-banner';
    <CookieConsent />

    Step 4: Configure the Banner

    Customize the banner's appearance and behavior by setting the appropriate props, such as the cookie categories, expiration dates, and callbacks for when users consent to cookie categories. Documentation from your library of choice will guide you through setting these options.

    buttonText="I agree"
    description="This website uses cookies to ensure you get the best experience on our website."

    Step 5: Integrate with GTM

    Once the banner is configured, link it with your GTM setup.

    More about Integrating GTM & SvelteKit

    You'll need to consider SvelteKit's SSR capabilities and find the optimal way to include the GTM script, so it executes correctly for both client-side and server-side rendered pages. Find out more in out full guide.

    Customize your banner's callbacks to listen to consent changes and push events to GTM's dataLayer. This will control the firing of tags based on the user's consent.

    function handleConsentUpdate(categories) {
    event: 'cookie_consent_update',
    cookieConsent: categories
    <CookieConsent on:consentUpdate={handleConsentUpdate} />

    Step 6: Testing the Implementation

    After integrating the banner into your application, test thoroughly across different browsers and devices. Ensure that the banner displays correctly, the user's preferences are saved and respected on subsequent visits, and that GTM tags are not firing without consent.

    Step 7: Deploy and Monitor

    Deploy your changes and monitor the banner's performance. Gather feedback from users about their interaction with the banner, and make any necessary adjustments to improve user experience or compliance.

    By following these steps, you integrate a cookie consent banner into your SvelteKit application that not only complies with legal standards but also aligns with GTM's consent-tracking requirements. This ensures your banners are both functional and legally compliant, providing a transparent and respectful user experience. Remember, maintaining user trust is paramount, and a well-executed cookie consent strategy is a significant step towards that goal.

    Creating a cookie consent banner is not just about fulfilling legal obligations; it's also about engaging users and respecting their preferences. A banner that feels intrusive or confusing can deter users from interacting with your site. Tailoring the cookie consent banner to align with your website's aesthetic and user experience is crucial in fostering user trust and maintaining engagement.

    Emphasizing Clarity and Transparency

    The primary goal of your cookie consent banner should be to provide clarity and transparency. Users should easily understand the purpose of the cookies and what they're consenting to. Use plain language and avoid technical jargon to ensure that your message is accessible to a broader audience.

    description="We use cookies to personalize content and ads, to provide social media features, and to analyze our traffic. By clicking 'Accept', you consent to the use of these cookies."

    Employ clear and concise descriptions, as well as straightforward calls to action. For instance, instead of a vague "Accept" button, you might use "Yes, I agree to cookies" to leave no doubt about the action being taken.

    Leveraging Design for Better User Experience

    Your banner's design should reflect the look and feel of your site to provide a cohesive user experience. Customizing the colors, fonts, and button styles to match your branding can make the banner feel like a natural part of your website rather than an afterthought.

    Consider the banner's placement and how it interacts with your site's content. A banner that obstructs essential elements or disrupts the user's journey may create frustration. Opt for a design that is noticeable without being obstructive, such as a discreet footer or a slide-in panel.

    Enhancing Interactivity

    Interactive elements can improve the user experience of your cookie consent banner. Provide clear options for users to adjust their cookie preferences. Libraries like the `@beyonk/gdpr-cookie-consent-banner` often allow for granular control, where users can toggle individual cookie categories on or off.

    categories={['analytics', 'marketing', 'functional']}

    By involving users in the decision-making process, you empower them to take control of their data. This interactivity can increase trust and potentially improve the likelihood of users consenting to cookie use.

    Providing Easy Access to Information

    Users may wish to learn more about your cookie policies before giving consent. Include links to your privacy policy or cookie declaration within the banner, making it easy for users to find more information if they desire. This transparency is not only good practice for user engagement but also a requirement for GDPR compliance.


    By crafting a cookie consent banner that marries compliance with user engagement, you strike a balance between fulfilling legal requirements and providing a positive user experience. Customizing your banner to be clear, transparent, and interactive demonstrates respect for your users' data privacy rights, which is integral to building and maintaining trust in your digital presence.

    Integrating a cookie consent banner with Google Tag Manager (GTM) is a critical aspect of ensuring your website adheres to privacy regulations. The goal is to make certain that GTM triggers tags only after obtaining user consent, particularly for tags that handle personal data or track user behavior.

    Understanding GTM and User Consent Flow

    Before delving into the technicalities, it's important to understand how GTM interacts with user consent. GTM serves as a central platform from which you can deploy various tags for analytics, marketing campaigns, and other services. Given its pivotal role, GTM must only execute tags that align with the user's consent choices.

    Setting Up a Consent-Triggered Tag Configuration

    To begin aligning your cookie consent banner with GTM, you'll need to set up a tag configuration that's triggered by user consent events. Utilize the dataLayer in GTM to push consent-related events that correspond with the user's choices on your cookie consent banner.

    window.dataLayer = window.dataLayer || [];
    function gtmConsentUpdate(consent) {
    'event': 'consent_given',
    'consent': consent // Object detailing consent per category

    When a user interacts with the cookie consent banner—accepting, rejecting, or updating their preferences—invoke this function to update the dataLayer. GTM can use these events to decide whether to fire specific tags.

    Utilizing Consent Initialization in GTM

    GTM's Consent Initialization feature allows you to specify the default consent state for each type of tag. For example, for analytics tags that require consent, you would set the default state to 'denied' until the user has explicitly agreed to analytics cookies.

    As users interact with the consent banner, dispatch events to GTM that change the consent state for each type of cookie. GTM will listen for these events and update the consent state accordingly, ensuring compliance with the user's preferences.

    Implementing a Variable-Based Tag Firing Strategy

    Employ GTM variables to capture and store the user's consent status. Create Consent Mode variables within GTM that mirror the categories on your cookie consent banner, such as 'analytics_consent' or 'marketing_consent'.

    When configuring tags in GTM, use consent-related variables as part of the firing triggers. Tags relevant to analytics, for example, would only fire if the 'analytics_consent' variable reflects that the user has given permission.

    Monitoring Consent with Trigger Exceptions

    Implement exception triggers to prevent certain tags from firing until consent is granted. For instance, if a user opts out of marketing cookies, an exception trigger can block all marketing-related tags from executing.

    'event': 'consent_update',
    'consent_analytics': 'granted' // or 'denied'

    GTM's built-in consent management will respect these exception triggers, ensuring that only compliant tags fire.

    Verifying Compliance Through Testing

    Once you have set up your GTM consent management strategy, it is crucial to thoroughly test it to ensure compliance. Employ GTM's Preview Mode to simulate various consent scenarios and confirm that tags are firing only when appropriate consent is given.

    Once you have integrated a cookie consent banner into your SvelteKit application and linked it with GTM, it is crucial to rigorously test and debug the setup to ensure that it operates as expected. This process helps validate that user consents are correctly captured and that the GTM tags are firing accordingly.

    Simulating User Interactions

    Begin by simulating user interactions with the consent banner across various scenarios. Accept, reject, and modify cookie preferences to assess whether the banner responds appropriately. Tools such as your browser's developer tools can help you monitor network activity and ensure that only the permitted cookies are being set.

    const consentBanner = document.querySelector('.consent-banner');
    consentBanner.dispatchEvent(new Event('consentGiven'));

    Preview and Debug Mode in GTM

    Google Tag Manager offers a Preview and Debug mode, which is invaluable for testing. This feature allows you to see a live version of your site with a debug pane that shows which tags fire on each page and why. You can use this to verify that GTM tags respond to consent updates from the dataLayer.

    'event': 'consent_given',
    'analytics_consent': 'denied'

    Automated Testing

    Automated tests can prove beneficial for verifying the functionality of your cookie consent implementation. Utilize end-to-end testing frameworks such as Cypress or Playwright to create scripts that mimic user behavior and check for correct consent handling.

    cy.get('.consent-banner').should('contain', 'This website uses cookies');
    // Check that the 'analytics' cookie is set
    cy.getCookie('analytics').should('', 'value', 'true');

    Checking Cookie Storage and Retrieval

    Ensure that your application correctly stores and retrieves user preferences. Cookies or local storage should reflect the user's choices, and these preferences should persist across sessions. This persistence guarantees that returning users do not have to consent repeatedly.

    // Example: Checking local storage for user preference
    const userPreference = localStorage.getItem('cookieConsent');
    if (userPreference) {
    // Apply user preferences in the application

    Monitoring Console Logs

    Be attentive to console logs for any errors or warnings that may indicate issues with your consent implementation. Console logs can provide quick insights into problems with script execution or potential conflicts between your consent logic and GTM.

    Cross-Browser Testing

    Different browsers may handle cookies and consent banners differently, so conduct cross-browser testing. Ensure that the banner functions as intended in all major browsers, including Chrome, Firefox, Safari, and Edge.

    Validating Consent Withdrawal

    Test the user's ability to withdraw consent and confirm that the consent banner respects this action. This step is essential for GDPR compliance, as users must have the ability to easily revoke consent once given.

    Performance Impact Assessment

    Assess the impact of your cookie consent implementation on site performance. The consent banner and related scripts should not significantly affect load times or the user experience.

    User Feedback Collection

    After your initial testing, collect user feedback to identify any usability issues. Real-world user interactions can provide valuable insights that may not be apparent during controlled testing.

    By thoroughly testing and debugging your cookie consent implementation, you ensure that your SvelteKit application remains legally compliant while providing a seamless experience for your users. Regular audits and updates of your privacy practices will keep you aligned with evolving legal standards and user expectations.

    Maintaining a cookie consent banner is an ongoing commitment that extends beyond the initial implementation. As data protection laws evolve and user expectations rise, staying abreast of best practices ensures your website remains compliant and user-friendly. Here are key strategies to keep your consent banners effective and up-to-date:

    Regularly Review and Update Your Cookie Policy

    Data protection laws, like the GDPR and CCPA, continue to mature, and regulatory bodies frequently issue new guidance. Regular reviews of your cookie policy are essential. Ensure it accurately reflects the cookies and tracking technologies in use on your site. Update the policy to accommodate new regulations, and align your consent banner accordingly.

    Simplify User Consent Management

    Simplicity is the cornerstone of user-friendly consent management. Users should have an easy way to review and alter their cookie preferences at any time. Consider adding a persistent, accessible control, like a "Manage Cookies" link in the footer of your website, which reopens the consent banner or redirects to a detailed cookie management page (Sanity's Privacy Policy provides a good example).

    Automate Compliance Checks

    With tools like the Klaro Privacy Manager, implement automated checks to monitor and enforce compliance. These tools can scan your site to identify cookies and tracking scripts, ensuring that your consent banner covers all data collection activities. They also facilitate the addition of new cookies to your consent banner as your site evolves.

    Incorporate User Feedback Loops

    User feedback is invaluable in refining the consent experience. Monitor user interactions with your banner and collect feedback through surveys or user testing sessions. Adjust the design and content of your banner based on this feedback to improve clarity and ensure users feel in control of their privacy preferences.

    Ensure Consistency Across Platforms

    If your brand exists across multiple platforms, such as a main website, subdomains, and mobile apps, ensure that your cookie consent practices are consistent across all touchpoints. Users expect a seamless experience, and consistent consent practices help reinforce trust and recognition of your commitment to privacy.

    Provide Multilingual Support

    For websites with a diverse audience, offer the consent banner in multiple languages to cater to all users. The consent banner should detect the user's preferred language and present the information accordingly. This not only enhances usability but also conforms to the multilingual requirements of regulations like GDPR.

    Test Accessibility

    Your consent banner should be fully accessible to all users, including those with disabilities. Follow Web Content Accessibility Guidelines (WCAG) to ensure that screen readers can read the banner content and that users can navigate the banner using keyboard controls.

    Educate Users Through the Banner

    Instead of merely seeking consent, use the banner as an educational tool. Provide concise explanations about the purpose of different types of cookies and how they improve the user experience. Informing users helps build a foundation of trust and transparency.

    Monitor for Third-Party Changes

    Keep an eye on third-party services integrated into your site, as they may change their cookie usage over time. Regularly audit these services to ensure that your consent banner remains accurate and up-to-date with these third-party practices.

    By adhering to these best practices, you can maintain a cookie consent banner that not only complies with legal requirements but also respects user choice and fosters a transparent environment. A well-managed consent banner is a statement of your brand's dedication to privacy, setting the stage for a relationship based on trust and responsibility with your users.

    As digital landscapes continue to prioritize user privacy, the implementation of cookie consent banners has a significant impact on analytics and marketing strategies. The way data is collected, analyzed, and used for targeting, personalization, and reporting is undergoing a fundamental shift, placing greater emphasis on consent-based user data.

    Respecting User Preferences

    Above all, cookie consent banners must respect user preferences, which means analytics and tracking must adapt to a scenario where not all users may consent to their data being used. This adaptation can result in gaps in analytics data, potentially affecting the accuracy and depth of insights. However, this challenge also presents an opportunity to refocus on the quality of user engagement rather than the quantity of data collected.

    Redefining Data Collection Methods

    The advent of cookie consent requirements necessitates a redefinition of data collection methods. Businesses must now identify which metrics are crucial for their operations and devise methodologies that gather this data in a non-intrusive way. Some analytics platforms are introducing features that allow for data collection in a world accustomed to consent banners, ensuring that essential metrics remain trackable within the bounds of user consent.

    Leveraging First-Party Data

    In response to restricted access to third-party data, there's an increased emphasis on the collection and utilization of first-party data. With user permission, first-party data provides a wealth of actionable insights that can inform personalized marketing efforts and improve customer journeys. This shift encourages brands to foster direct relationships with customers, thus building a more reliable data ecosystem.

    Innovating with Privacy-Friendly Solutions

    Marketers are now prompted to innovate with privacy-friendly solutions, exploring alternatives that do not rely on extensive tracking. Solutions like contextual advertising, which uses the content of a page rather than user behavior to serve relevant ads, are seeing a resurgence. Moreover, the growing field of AI and machine learning offers potential avenues for predictive analytics and customer segmentation without infringing on user privacy.

    Prioritizing Transparency in Marketing

    Transparency in marketing communications is now more crucial than ever. Users want to know how their data is being used and for what purpose. Clear messaging and transparency strengthen user trust, which can translate into higher consent rates and a stronger brand reputation. Marketing strategies must align with this principle, prioritizing trustworthiness and ethical data practices.

    Optimizing Consent Experience to Maximize Opt-ins

    An optimized consent experience can maximize user opt-ins, and consequently, the amount of usable data for analytics and marketing. Customizing the cookie consent banner to reflect the brand's voice, providing clearer options, and explaining the value exchange can encourage more users to consent to cookies. Focusing on the user experience of the consent process itself, therefore, becomes a strategic priority.

    Adapting to a Changing Ecosystem

    Lastly, as regulations and technologies evolve, so must the strategies surrounding them. Staying informed about changes in privacy laws, browser functionalities, and analytics technologies is critical. Businesses must be agile, ready to adapt to a changing ecosystem where user consent plays a central role in determining the scope of digital analytics and marketing initiatives.


    Crafting a compliant cookie consent banner for SvelteKit and GTM is more than a legal necessity; it's a gesture of goodwill towards user privacy in a digital age where trust is paramount. User consent can no longer be an afterthought—it must be the core consideration in how we collect and utilize data. This article has guided developers, marketers, and SvelteKit enthusiasts through the intricacies of integrating a robust consent mechanism, ensuring a seamless user experience while maintaining compliance with privacy regulations such as GDPR and CCPA.

    The selection of the right cookie consent library is crucial, emphasizing user engagement and transparency. The need for careful integration with GTM ensures that analytics and marketing strategies remain effective yet respectful of user choices. Testing and debugging are vital to confirm that the consent implementation behaves as expected, capturing user preferences accurately and integrating flawlessly with analytics tools.

    Maintaining a user-friendly cookie consent banner requires regular updates reflecting current data protection laws, allowing users to easily manage their preferences, and ensuring cross-platform consistency. It should also be accessible to all users and provide educational insights into the use of cookies. First-party data gains prominence as we shift focus towards direct customer relationships, and innovative, privacy-friendly solutions become integral to modern marketing efforts.

    In embracing these best practices, organizations fortify their commitment to user privacy, fostering a trust-based relationship with their audience. As consent-based data collection reshapes the foundations of analytics and marketing, a proactive and considerate approach will not only uphold legal compliance but also reinforce the brand's integrity and customer loyalty. Ultimately, the true measure of success in this consent-driven environment lies in upholding user trust—a responsibility and privilege for every digital platform.

    Richard Lawrence

    About Richard Lawrence

    Constantly looking to evolve and learn, I have have studied in areas as diverse as Philosophy, International Marketing and Data Science. I've been within the tech space, including SEO and development, since 2008.
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