SharePoint Online / Office 365 search engine can't index Excel files bigger than 3 MB !!!
I recently discover a huge limitation on SharePoint Online Search engine.
Please take a seat : SharePoint Online Search engine can't index content of excel files if files are bigger than 3 MB !!!! (not 30MB, nor 300MB, but yes 3 MB !!!!!!!)
For example if your excel workbook is a 4Mb file, the only things which will be crawled are metadata : Title, File name .....
This limitation is very strange : note that this limit is only on excel file, if your document is a Word (.docx) PDF (.pdf) , ... content is crawled until 64 MB which is honnestly a good size for an office file.
How to fix it ? Sadly i had to suggest to my customer to cut his workbooks in separated files smaller than 3MB ..... and wow it's magic, content is crawled :'(
Search limits for SharePoint Online [ Official Office Support ]
https://support.office.com/en-au/article/Search-limits-for-SharePoint-Online-7c06e9ed-98b6-4304-a900-14773a8fa32f
