Free Support Forum -

Groupdocs Upgrade


We had implemented Groupdocs Annotation and Viewer for one of our client in 2012/13. The version of sdk’s being used is 2.12.164.
The application is in .net 4.0 and we want to upgrade the groupdocs. Can you please provide the latest compatible version available for .net 4.0 and the performance enhancements if any available.
We are providing Annotation and Viewer files from Azure blob storage.



Please note that all GroupDocs next generation APIs (starting from 3.x) support .NET Framework starting from V2.0. Secondly, these are back-end, UI independent APIs and can be integrated in any .NET (existing or new) applications.
You can use both APIs and develop UI on your own. However, we have some open-source showcase projects for your ease. You can explore them in order to get idea, how API is working:

GroupDocs.Annotation for .NET

GroupDocs.Viewer for .NET

GroupDocs next generation APIs are improved and have extended features.
We’d recommend you to explore developer guide and features overview of both APIs:


Thank you for providing the demo annotation link. We ran the code and we have to upload the file into annotation tool. How can we load the file on page load when file are saved on Azure storage.

Also wanted to know if callback function is still provided when an annotation is added to the file?



We are investigating this. It has been logged in GitHub. Please follow this link for further correspondence and updates. However, we’ll also notify you here as we have any update.

No such feature is supported by the back-end API itself. However, you could achieve this at code-level (you can implement such feature in your showcase project).


Hi atirtahir3,

Is their a way to optimise the existing annotation tool implemented in our application?



Please clone/download latest version here. You can set annotation configuration options in configuration.yml file. Set defaultDocument to absolute path to default document that will be loaded automatically.
As far as fetching file from Azure storage is concerned, this feature is not yet implemented. However, please explore this documentation and you will see how API works with data storage.

Can you please tell which application you are talking about?


We are using Viewer and Annotation on



Please note that versions older than 3.0 are obsolete and their support is discontinued.