I have an Azure SQL Elastic Pool with 800 eDTUs and 400GB of Storage.
In past, I used to have 400 eDTUs, and when I scale to 800 eDTUs I had a small downtime in the website (~15-30 seconds), so before making any changes to the storage, I'd like to check if I should expect downtime as well.
Does anyone know?
We do scaling real-time in eDTU's and DTU's and no downtime observed. URL :https://learn.microsoft.com/en-us/azure/azure-sql/database/scale-resources

I don't think don't need downtime when you Increase DTU's. Definitely, there is certain impact which you can read from here
Regardless, the switch can result in a brief service interruption when databases are unavailable generally for less than 30 seconds and often for only a few seconds
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