Friday, February 26, 2016

8 things you may not know about Google Tag (Assistant) Recordings

Many people know Google Tag Assistant and use it as a tool to quickly look at their Google Analytics (and other) tags on their website. A few months ago we launched a new product: Google Tag Recordings which we integrated with Google Tag Assistant.

The idea behind Tag Recordings is that you as a GA user can record a journey through your website and then look at how GA would process the GA hits. This lets you validate that your site works correctly with GA. If there's an issue, you can troubleshoot it on the spot, make changes --for instance to the GA configuration-- and instantly see the effect of your changes.

Here is a 2 minute demo:

Here are 8 things you perhaps didn't know about Google Tag (Assistant) Recordings:

1. It’s a service!

Although integrated with Tag Assistant, Tag Recordings is a standalone service. It lives at this URL: It being a separate service instead of javascript in the browser, lets it use some of the same GA parsing and processing code that GA normally uses.

To use Tag Recordings, you need to have a recording of a journey through your website. The recording is in the form of a HAR. The easiest way to record is to use Google Tag Assistant: just hit the record button. But you can also use the record functionality in the Chrome Devtools. You can also use Firefox or IE or construct your own HAR.

2. Dropped hits? Check hit parse errors!

If you make an error in --for example-- the number format of an event sent from your web page, the hit will be rejected when it arrives at because the hit cannot be parsed. Example:
  ga('send', 'event', 'cat', 'act', 'lab', 5.2);
This fails to parse in the GA server because the last parameter must be an integer. The parse error does not make it back to your web browser, so you don't know that your hit will never make it into any reports.

While Tag Assistant does not show the error (it only does a small set of validations in the browser itself), Tag Recordings however does show the parse error: it uses the same code that the Google Analytics server uses.

3. No hits? Find the filter that is to blame

If you see no hits at all in a GA View, a filter may be to blame. Views often have lots of different filters, making it difficult to quickly see which filter is to blame. In Tag Recordings you can see if a hit is dropped for a View, and if so, which filter is responsible.

4. Mutating filters

Filters may change attributes of a hit. Also View settings may mutate hits, for example for query parameter stripping. Tag Recordings shows exactly how a hit changes after it is sent.

5. Find session breaks

Going from one domain to another domain may cause GA to start a new session. This of course will have a big impact on your GA reports. Because Tag Recordings looks at all the hits in a recording, it can figure out where GA would create a new boundary. See for an example the video above or this example report.

6. Verify your goals, filters, etc

When you create a new goal or filter, Google Analytics allows you to preview how the goal or filter will work using hits that were received and processed previously. For this to work the View already must have data, obviously. How the actual filter or goal will work, can only be seen after a day or so when new hits have come in and have been processed.

A powerful feature of Tag Recordings is that it operates on the current configuration of your property and view. So you can get instant feedback on what happens to hits if you change the configuration. That allows you to instantly validate changes to filters, goals, etc.

7. Pretend to be elsewhere

Once you have a recording, you can pretend that the recording was made from a different specific IP address, or you can pretend that the IP address belongs to a different geo. This makes for a quick approach to verify that your IP-specific or geo-specific filters work as you would expect them to work.

8. Troubleshoot GCLID problems

If you click on an ad in Google Search and you have setup autotagging, the GCLID needs to be propagated from all the way to the the ads landing page. If you have redirects in between, for instance because all traffic for mobile devices is redirected to a different sub domain, the GCLID may be mangled or dropped. This results in seeing fewer sessions in your GA report than ad clicks.
Tag Recordings reports all redirects and warns you if a GCLID gets dropped or mangled in a redirect. Example report

A demo site for Tag Recordings

If you want to try out Tag Recordings yourself, you can record a journey through a sample site at This site will send various types of hits and show several different problems.
Before you go there, first create a new GA property. Next, enter the UA-string on the site so that the hits will be sent to this new property. This allows Tag Recordings to use the configuration of your property and display all the information associated with the hits. It also allows you to make changes to the GA configuration of the property so that you can see what happens due to the configuration change.

More information