It's typically not a good idea in general to have two tag managers deployed on the same site. Can I ask why you're trying to install both on the same site? If you are just testing both tag managers, could you use them on different sites or different sections of the same site?
Deploying one tag manager using another won't ever be supported and can lead to unreliable deployments
Success rates of having one tag manager interact with another will be unreliable at best
The more you have running/loading on your page, the slower it will load. If you're loading two tag managers, you're doing everything twice.
Data will likely not match since different tools and tag management systems will have different methods of collecting and sending data
Is there a specific reason you want to deploy both on the same site? DTM is able to deploy any pixel/code you'd like. Almost all limitations of DTM are being addressed with Adobe's newest tag management offering Launch, by Adobe
Sounds like a great opportunity for someone to write a "perfect" extension in launch for the integration.
Launch is being built as an open platform where customers and third-party consultants will be able to build their own extension. This will allow for our experts within the community to build integrations with just about any pixel/tag out there. We will no longer be limited by having a single team being responsible for every integration and extension.
Thank you Jantzen. Agreed with everything mentioned here. The main reason for deploying both is related to media tracking and Google Adwords integration. The client wants to continue using AdWords, and I've heard Adobe's integration with it isn't perfect...
Hello! I have a similar question, and would like to fully understand key disadvantages of having both GTM and DTM on the same site. Site speed? Inconsistency in data? Any other reasons not to have both running at the same time? Would appreciate any references to official sources where this can be outlined. Thank you in advance!
My question is just to confirm something. I don't intend to add two TMS in the same site but I need to see other opinions about this topic. DTM is not very popular in Brazil, so I thought I'd better ask.