Companies Using Partytown

Mostly small sites built with Astro or WordPress: in a random 40 we loaded on 14 November 2026, 14 were Astro sites and 8 used WordPress's Web Worker Offloading plugin. Larger users include Brazilian retailers on VTEX FastStore, such as Americanas and Fast Shop, plus EA's help centre, Mahindra's auto site and Unacademy.

Our November 2026 crawl counts 11,370 domains running Partytown, after removing for-sale and gambling pages, alias and duplicate domains, and marketplace placeholder pages, 5.2% of the raw count. 6,652 match a company. They are domains, not customers: Partytown is free. Since tracking began on 16 March 2026, 3,010 domains dropped it from every hostname we saw.

0.08% of Performance Optimization at TechnologyChecker.io, 14th of 45 rows, with 11,370 domains. Priority Hints (91.95%) is a browser attribute rather than a product. Among tools, Autoptimize (1.76%) and WP Fastest Cache (1.55%) lead. Cloudflare Zaraz, the nearest match to Partytown's job, is 10th at 0.2%.

Cloudflare Zaraz, which runs third-party tools from Cloudflare's servers (26,318 domains in our crawl), and server-side tagging, which moves tag work off the browser altogether. Lighter options delay scripts rather than move them, such as Cloudflare Rocket Loader (152,136 domains), which defers a page's JavaScript until after rendering, per Cloudflare's docs.

By matched companies: the United States (2,431), Brazil (718), India (344), the United Kingdom (318) and Canada (206). Brazil's place is partly one platform: six of the top 25 companies on our list run Brazilian online stores on VTEX FastStore, which ships Partytown.

Small, mostly. 59.74% of matched companies with a known size have 1 to 10 employees and 25.67% have 11 to 50. 135 have more than 1,000 staff; those usually run it on a storefront, help centre or customer area, such as Americanas, EA's help centre and Safaricom's customer portal.

Young, mostly: 37.09% of matched companies with a founding year started in the 2010s and 28.77% in the 2020s. 14.29% date from the 2000s and 19.85% predate 2000, including Mahindra & Mahindra, founded in 1945, which runs Partytown on its auto site.

On our data, a company with 1 to 10 staff in the US, Brazil, India or the UK, founded in the 2010s, in retail, construction or software, whose site is built with Astro, Next.js or WordPress and uses Partytown to run Google's tag in a web worker; 87.45% of these domains have Google Tag Manager.

It moves resource-heavy third-party scripts, such as analytics and ad tags, into a web worker so they don't compete with your own code on the main thread, per its docs at partytown.qwik.dev. You mark each script with type="text/partytown", and Partytown runs it in the worker, relaying its calls to the page.

It started at Builder.io, whose npm package @builder.io/partytown last updated to version 0.10.3 in December 2024. Development now happens in the QwikDev organisation on GitHub, which publishes @qwik.dev/partytown; version 1.0.5 came out on 7 November 2026. The licence is MIT, per the repository.

Partytown's docs list integration guides for Angular, Astro, Drupal, Gatsby, Magento 2, Next.js, Nuxt, Qwik, React, Remix, Shopify Hydrogen, Shopify OS 2.0, Solid, SvelteKit, TanStack Start and WordPress. In our random 40, Astro (14 sites) and WordPress's Web Worker Offloading plugin (8) were the most common routes, then Next.js (4).

Yes, and it's the most common use in our data: Google Tag Manager shows on 87.45% of Partytown domains, and at least 16 of 33 running sites in our sample sent gtag.js to the worker. Partytown's docs have a Google Tag Manager guide. Its trade-offs page warns that some behaviour, such as calling preventDefault on events, won't work from the worker.

It depends on the scripts. Partytown's docs say it isn't guaranteed to work in every scenario, Next.js calls its worker strategy experimental, and WordPress's Web Worker Offloading plugin says its feature is intended to be sunset. Large sites run it anyway: Americanas, EA's help centre and Unacademy all loaded it on 14 November 2026.

Look in the page source for scripts with type="text/partytown" and a small inline config that sets partytown, then for files under /~partytown/, such as partytown-sw.js. WordPress sites with the Web Worker Offloading plugin show an inline script with the id web-worker-offloading-js-before, and Next.js adds a data-partytown-config script.