64K Limit in Rich Text Fields / Too Many File Attachments

You may have come across this situation before: you try to place a large number of file attachments into a rich text field and, at some non-deterministic count, you get an error message stating that a 64 KByte limit has been reached. This is the 64K limit.

You often read about this 64K limit, and people tend to overlook the fact that it does NOT refer to the maximum size of a rich text field — and certainly not with regard to the file attachments it contains. For example, you can attach ONE file of 100 MB to a rich text field without any problem. But if there are a lot of files, the issue shows up — without being easy to pinpoint exactly.

The 64K limit exists within a rich text field for a single "paragraph". A paragraph in Notes is defined the same way as in a word processor: it starts after a "hard return" and ends at the next "hard return".

When you select a very large number of files and Notes starts attaching them to the rich text field, an icon including the file name and management information is written into the rich text field for each file — not the actual file content itself, which usually ends up in the $FILE fields (you can inspect this via the document properties after saving the document).

And all of this goes into the SAME paragraph — WITHOUT any "hard line break" (@NewLine) being inserted. I can't say exactly how much space each attached file occupies (icon + file name + internal management information), but at some point the 64K limit for that paragraph is reached. And that is what causes the error message described above.

You can easily test this yourself: attach files in "batches" of, say, 25 at a time. Then press Return (which ends the paragraph) and attach the next 25 files, and so on.

This way you can fit several hundred files into a single rich text field without any problems.