Continuing from Your free and standby Microsoft Office alternative: Office Online to start go to https://www.office.com/ , login to your MS account (if not already logged in).
Click on the buttons for Word Online, Excel Online, PowerPoint Online or OneNote Online. Also, a link to OneDrive where all the Office Online documents are saved. Scroll down the web page to see a list of recently opened documents.
Or go to https://OneDrive.com to directly get into OneDrive and the available documents.
Microsoft wants people to put all their documents in their OneDrive service and has designed Office Online (and other Office apps) to prefer OneDrive. But that doesn’t mean you have to do what Microsoft wants.
You have to upload into your OneDrive storage then open the document from there into Office Online. It’s not possible to simply upload a document directly into Office Online.
From your computer
Here’s how to use Office Online with documents saved on your computer. In short, upload the document to OneDrive, switch to Word/Excel/PowerPoint Online to open the document, then save back to your computer when finished. If you wish, delete the OneDrive copy.
This is easier if you have the OneDrive program/app running on your Windows/Mac computer. OneDrive apps can synchronize files or folders between your computer and the OneDrive online storage. For this example, we’ll assume there’s no synchronization available (i.e. you’re using someone else’s computer or a public terminal).
Go to your OneDrive account https://onedrive.live.com/ and upload your document using, surprise, surprise, the Upload button. Choose a folder or use the main/root folder.
Once the document is uploaded, find it in OneDrive, click the little menu icon then ‘Open in Word Online’.
Or choose ‘Open in Word’ to use Word software on your computer.
All Office compatible documents saved in your OneDrive account can be opened in Office Online. PDF files can be viewed, but not converted/edited (that requires Word software).
Save to your computer
When you’ve finished editing, go to File | Save As to save/ download a copy of the document to your computer.
The original document is saved on OneDrive (Office Online auto-saves, there’s no Save button). Of course, you can download any file/document from OneDrive.com too.
You can Save As to PDF on your computer but, strangely, can’t save a PDF copy direct to OneDrive.