JavaScript tracker backward compatibility



I wonder if there is backward compatibility guaranteed in JavaScript trackers? The issue is as follows: on our sites we use tracker version 2.6.2 (planning to update soon), but I have found, one of 3rd parties also uses Snowplow and loads tracker version 2.9.0. I have found, that in about 1% cases 3rd party code loads faster and our site uses never tracker. As 2.8 has introduced major change (unstruct event -> self describing event), potentially some issues may be observed. I am trying to estimate if there could be any data loss and potential size.


Hi @grzegorzewald,

The new tracking method for custom events was released in v2.7. The old trackUnstructEvent method is still compatible and will still work.

This change was introduced in the name of avoiding misunderstandings in the nature of custom events - the name ‘unstructured’ is misleading as they are in fact highly structured.

With this:

our site uses never tracker.

I think this is in reference to the respectDoNotTrack method, which should also still function as before. v2.8 also introduced opt out cookies as a different method of providing a similar functionality - it enables you to save an ‘opt-out’ cookie which if enabled prevents tracking. This should be useful in managing consent in relation to GDPR, for example.

I hope that is helpful - any follow up questions let us know!


Thanks for info - I have verified working unstructured events.

i did typo in - i meant up to date tracker version.

respectDoNotTrack was generally not the best idea, as some browsers have it set to true by default.


Agreed - there are always considerations which hamper how we’d ideally like things to work.

I may be projecting my own thoughts onto the below rather than giving a representation of what the product-design thinking was, but I think that’s why respectDoNotTrack defaults to false - in an ideal world it’s set to true so that users don’t inadvertently track users without consent, but that limitation makes this impractical. The opt out cookie gives us more control over consent management though, which I’m hopeful of in terms of the future of ethical data collection.

Bit of a tangent there - happy to help in any case :slight_smile: