There are a few big draws for Google Docs, which is Google’s online word processing software. As with most Google products, Google offers a lot of storage for free (15 GB at last check), which is likely to be the best option you can find with any product on this list.
Google Doc Alternatives

Proton Docs (and Drive)
Free tier storage: 2 GB
Proton is a Swiss privacy-focused company that has a handful of software offerings competitive to Google. Expect to see their name crop up throughout similar lists with Google alternatives.
Proton Docs offer end-to-end encrypted storage of documents, which means only you can view the data on the files. The editing capability is fairly minimal at the moment, but you can write basic documents fairly easily. If you’re looking for a Microsoft Word replacement, this might not be the product for you. For example, you can’t change the spacing between lines or the size of the margins on your document. They also only have a limited number of text fonts and colours for text & highlighting. But as far as a bare-bones document editor goes, Proton Docs seems really simple to use.
Alongside Proton Docs, you’re given access to Proton Drive, which is their Google Drive competitor. The same deal applies for Drive: namely, files are end-to-end encrypted, so Proton (and anyone sitting along the way to Proton’s servers) can’t see what you’re storing.

Microsoft Word Online
Free tier storage: 5 GB
Another juggernaut in the document editing space, Microsoft Word has moved to be cloud-native software. This means collaboration and the ability to access a file anywhere comes naturally. Since Microsoft is one of the original word document companies, there are tons of features available in Word. The main downside I’ve found with Word online is that it is online-only, often becoming completely unusable if you’re on spotty WiFi or don’t have internet access.
Connectivity aside, this is the closest alternative in terms of features offered, often giving you even more ways to customize your documents than even Google Docs offers. And with 5GB of free storage available, there’s actually a lot going for Microsoft Word here.

LibreOffice Writer
Free tier storage: N/A
LibreOffice Writer is a powerful alternative to Google Docs or Microsoft Word, as long as you don’t need online access. This is software that you run from your computer, like Microsoft Word back in the olden days, so if you want to share your documents with someone else, you have to use some old-school methods like email attachments. It is fully open-source software, meaning you can go look up the code yourself (and even change it if you really want to). LibreOffice also offers their whole suite of office productivity tools (think Microsoft365 competitors) free for download on their website.
Because this is software that you run on your computer, there’s no need for an account and the only way you run out of storage is if your computer is full. There also isn’t a concern around who has access to your data, as long as your computer is kept reasonably up-to-date.
While it’s not a direct one-to-one Google Docs competitor, it’s worth considering which features you actually need for your Google alternatives. Online access means your document needs to be stored somewhere that’s accessible via the internet, which introduces a whole slew of considerations by itself. Sometimes, offline-only is a great solution to this type of problem.

Etherpad
Free tier storage: N/A*
On the note of open-source competitors with online access, Etherpad offers simple document editing without offering the hosting/storage of those documents. Similar to peer-to-peer platforms, Etherpad simply supplies the software you need to run somewhere. They do offer a list of public servers that can host your data, but keep in mind that this means your documents will be on someone else’s computer. Maybe keep that list of passwords on your computer instead…
If you’re feeling confident or want to bump up the learning curve, you can always host Etherpad yourself. Then you decide the access and storage yourself. Think of this as slightly more complicated than hosting your own website.
*Storage limits likely depend on the server you’re using.

CryptPad
Free tier storage: 1 GB
Last but not least, CryptPad is a free document writing program that offers end-to-end encryption without an account. This means that even if you’re storing a document on someone else’s computer, they won’t be able to see your data. There are some obvious limitations if you don’t have an account, but this is one of the only options I found that performed decently well and doesn’t throw a login screen in your face.
The UI is reminiscent of Microsoft Word a decade ago, but it seems to get the job done fairly well. If you’re feeling bold, you can also run/host CryptPad yourself for the added benefit of owning your own document storage.