We're sorry Aspose doesn't work properply without JavaScript enabled.

Free Support Forum - aspose.com

Max doc size for doing a mail merge?

Hi - We are a licensed user of Aspose.Words for Java and trying to utilize it to do Word mail merges. Some of these documents being merged are in the range of 5000-6000 pages.

We have done a POC with this size of document and it ended up running out of memory after 2 hours of processing.

Has anyone dealt with a mail merge of this size using Aspose.Words and if yes, what memory configuration did it require and approx how long does it take to complete?

We are still messing with different configurations, but any thoughts or best practices when dealing with his size of document would be much appreciated.


Hi Brian,

Thanks for your request. There is size limit of document you can generate using Aspose.Words. The only limit is the amount of RAM available on your side. Usually Aspose.Words needs few times more memory than document size to build model of the document in memory. For example if your document’s size is 1 MB, Aspose.Words needs 10-20 MB of RAM to build its DOM in memory. Multiplier depends on format also because some formats are more compact than others. For example DOCX format is more compact than DOC and RTF, and DOC is more compact than RTF.

Also, I would like to say that producing huge MS Word documents is not very good practice. MS Word does not like huge documents. Usually it takes a lot of time to open such documents in MS Word and sometimes MS Word just hangs. Normal size of MS Word documents is 100 – 200 pages.

So the only way to work the problem around, I can suggest you, is producing few small documents instead of one huge document.

Best regards.

Thanks for the insight Alexey. We are running some metrics and getting a better idea of how Aspose.Words utilizes memory so making good progress as we get more familiar with it. I hear what you are saying about the file size and that is something we will be addressing with the project team on if it is a possibility to deal with smaller documents and just package them together.


It is perfect you have enough information to move forward. Please feel free to ask if not need more information or assistance, we are always glad to help you.

Best regards,