Many cloud storage providers require your full trust that they will not look at your files. The alternatives listed below eliminate the need for trust by either putting you in control of your data or by implementing E2EE.
If these alternatives do not fit your needs, we suggest you look into Encryption Software.
Cryptee is a web-based E2EE data storage service. It primarily focuses on photo and video storage as well document editing. Cryptee is a PWA, which means that it works seamlessly across all modern devices without requiring native apps for each respective platform.
Cryptee offers 100MB of storage for free, with paid options if you need more. Sign-up doesn't require an e-mail or other personally identifiable information.
Proton Drive is an E2EE general file storage service by the popular encrypted email provider Proton Mail.
Proton Drive is currently only available through a web client and an Android app.
Nextcloud is a suite of free and open-source client-server software for creating your own file hosting services on a private server you control.
We don't recommend using the E2EE App for Nextcloud as it may lead to data loss; it is highly experimental and not production quality.