From Urchin to GA4: The Complete History of Google Analytics

Updated: December 18, 2025

Google Analytics originated from a product that Google acquired rather than developed entirely in-house.

Urchin: The Beginning

Quantified Systems（the predecessor of Urchin Software Corporation） was founded in 1995 in San Diego, initially providing website development and server hosting services.

The founding team—Brett Crosby, Scott Crosby, Paul Muret, and Jack Ancone—soon identified a common challenge: clients often needed a full day or more to process website data.

To solve this, they envisioned an analytics tool capable of processing one day of data in just 15 minutes. This idea led Paul Muret to develop the first version of Urchin in 1997, which was released in 1998，originally as a supporting feature for their services. 

In 1999, Quantified Systems rebranded as Urchin Software Corporation, marking a strategic shift toward web analytics as its core focus, with Urchin positioned as its flagship product.

The following outlines Urchin’s version history and key feature updates:

GA1：Google Analytics（urchin.js)

In April 2005, Google acquired Urchin Software Corp., and the Urchin was rebranded as “Urchin from Google.”

In November 2005, Google launched Google Analytics（GA1）based on Urchin 7. The main JavaScript file urchin.js, was retained in this initial release. Due to overwhelming demand, new sign-ups were suspended just one week after launch. As the system capacity expanded, Google adopted a lottery-style invitation system to manage access. The tracking code at this time looked like this:

<script src=”http://www.google-analytics.com/urchin.js” type=”text/javascript”></script>
<script type=”text/javascript”>
   _uacct=”UA-123456-1″;
   _userv=2;
   urchinTracker();
</script>

By August 2006, the invitation system was discontinued, and Google Analytics became fully available to all users.

GA2：Google Analytics Classic（ga.js）

In April 2007, Google Analytics launched the Synchronous Code, which used the ga.js library.

In June 2009, Event Tracking became available.

In December 2009, Google Analytics released Asynchronous Code, designed to reduce ga.js latency on webpages. 

In October 2012, Google Tag Manager were released.

In December 2012, Google Analytics with Display Advertising was introduced. This update improved remarketing capabilities for display ads and added Enhanced Link Attribution,

GA3：Google Analytics Universal (analytics.js)

In October 2012, Google introduced Universal Analytics（UA、GA3）,  which used the analytics.js library. the tracking code at this time is as follows:

<!-- Google Analytics -->
<script>
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
ga('create', 'UA-XXXXX-Y', 'auto');
ga('send', 'pageview');
</script>
<!-- End Google Analytics -->

In 2013, Google released Ecommerce Code, using the plugin:

ga('require', 'ecommerce');

In Mar 2013, Google releases Measurement Protocol.

In Jun 2013, Google releases Attribution Models.

In September 2013, with all Google searches moving to HTTPS, organic keyword data became unavailable in Analytics, causing the familiar “(not provided)” entries to appear in keyword reports.

In May 2014, Google released Enhanced Ecommerce, using the plugin:

ga（'require'，'ec'）

GA4：Google Analytics 4 (gtag.js)

In October 2017, Google introduced the Global Site Tag (gtag.js), unifying tagging across Google Ads, DoubleClick, and Google Analytics to simplify implementation. The tracking code at this time is as follows:

<!-- Global site tag (gtag.js) - Google Analytics -->
<script src="https://www.googletagmanager.com/gtag/js?id=UA-XXXXX-X" async=""></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'UA-69988360-20');
</script>

In September 2019, Google introduced App + Web, enabling unified tracking for apps and websites. The tracking code at this time is as follows:

<!-- Google tag (gtag.js) -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-HZ4RDGTX66"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'G-HZ4RDGTX66');
</script>

In October 2020, App + Web was rebranded as Google Analytics 4 (GA4), marking the next generation of Google Analytics.

In September 2021, Server-Side Tagging moved from beta to general availability, supporting multiple Google products—including GA4—while offering improved privacy controls and performance optimizations.

In July 2023, all free Universal Analytics (UA) properties stopped processing new hits, completing the phase-out of data collection.

In July 2024, all GA360 properties based on Universal Analytics also stopped processing new hits.

In July 2024, First-Party Mode (FPM)—later rebranded as Google Tag Gateway—was introduced to support first-party data collection and improve data durability.

In May 2025, First-Party Mode was officially renamed Google Tag Gateway, reinforcing Google’s focus on first-party measurement and privacy-centric tracking.