Zaraz is now part of Cloudflare!

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Make your website 40% faster

Zaraz loads your third-party tools without slowing down your pages. Allow your team to add all the tools they need without worrying about damaging your performance.

Key Benefits

Improve performance and user experience by making your website faster

Save engineering hours; focus on your own code while we deal with your third-parties

Stop pasting obscure <script> snippets into your pages. Let us integrate those tools wisely

Juan Biltes

Sr. Software engineer at Mercado Libre

“Third-party tools have a severe impact on web performance, which hurts revenue. Even large companies with dedicated web performance teams tend to lose track of what tools they're loading. Having the capability to manage and optimize third-party tools is a dream come true.”

Case Study: Loading the Facebook Pixel

Every tool added to the Zaraz library has gone through extensive research to figure out the most efficient way it could be loaded. We conclude what parts of it we can run on our backend, what must happen in the browser, when, and more. We choose from our variety of loading techniques and we often mix them. See below to learn how we’re loading the Facebook Pixel.

  1. User loads a website with the Zaraz script.
  2. The script notifies the Zaraz backend about the different properties of the visit: page, browser, device, relevant cookies and more.
  3. The Zaraz backend evaluates the information, and looks for the Facebook Pixel cookie.
  4. If the Facebook Pixel cookie is included, the Zaraz backend contacts Facebook through the Server-Side API, and registers the page view event with the cookie value. In this scenario, the browser does not load any Facebook script or connect to any Facebook server at all.
  5. If the Facebook Pixel cookie does not exist, Zaraz bundles the original Facebook Pixel in the response it sends to the browser. It will include all other third-party scripts Zaraz needs to load on the client side – each with their unique settings.
  6. To prevent the Facebook Pixel from slowing down the page, Zaraz waits until the website reaches interactivity before executing it. Once the Facebook Pixel is loaded for the first time, a cookie will be created, which Zaraz picks up and uses to avoid loading the script again in all future events.
  7. If the user leaves the website before the Facebook Pixel was loaded, Zaraz uses its Load On Exit technique to still send the page view event to Facebook. It does so by constructing all the request parameters on the backend and attaching a simple fetch call to the page unload event. No data is lost and all page views are recorded.
Zaraz loads the Facebook Pixel in a smart way

Novel Architecture

A multitude of unique features to free your end users’ browser from downloading and executing countless excessive scripts.

Cloud Load

Zaraz allows most tools to send their information through the Zaraz backend, replacing multiple network requests with a single request. The request is then adjusted to the tool data structure and forwarded to their server without running any scripts on the user's browser at all.

Cloud Render

For the majority of popular conversion pixels, Zaraz mimics the script behavior on its backend and then makes the browser fire the already constructed request, meaning no third-party JavaScript is ever delivered or evaluated on the browser.


Zaraz replaces heavy third-party widgets with a lighter-weight version that loads first so that the full-featured tool loads only when the browser reaches interactivity or upon user interaction.

Selective Load

Since some tools work only on a sample set of your visitors (e.g., session recording tools), Zaraz prevents the delivery and parsing of their JavaScript by the user’s browser when it’s not needed.

Smart Defer

Zaraz delays loading of specific tools until after the website reaches interactivity so they won’t compete with the website for the same resources. To ensure data collection is working properly, Zaraz prebuilds the necessary outgoing requests and fires them if the page was closed before the delay window finished.

Request Bundling

For session recording tools, Zaraz creates one bundled script by prefetching required assets, saving the browser from making hundreds of separate HTTP requests. It also takes care of updating the main script when those external resources are updated.

Script Inlining

For tools that need to be loaded as early as possible (e.g., A/B testing tools), Zaraz fetches third-party scripts and inlines them in the website HTML as part of your CI/CD process.

Zaraz is easy to implement

Effortless Integration

Zaraz loads your third-parties

Just add the Zaraz script to your page, and it will load everything else as needed. All further configuration can be done through the Zaraz Dashboard. It’s as easy as adding the simplest third-party tool, and it’s the last tool you’ll ever need to add.

Send data using our Events API

Zaraz provides you with a unified and simple set of functions to send data programmatically to your third-parties. Regardless of the tool, zaraz.track() will send your data wherever you choose, without even loading the tool’s script.

Seamless migration

Automatically migrate all your existing third-party stack from your current codebase, tag management software, or customer data platform. No need to reconfigure your events and triggers. Zaraz even comes with optional dataLayer support.

Improve Your Website’s Speed Today

See for yourself how Zaraz improves your website speed and helps you manage your third parties.