Decentralized cloud storage you own

Pithos itself — the control panel, the Theseus add-on, the desktop app — is 100% free and open source. There is no paid tier, no feature paywall, no ads. What you pay for is the Sia storage underneath, charged by your Sia indexer (for example sia.storage) at a few cents per GB per month, pay-as-you-use with no monthly subscription. No credit card is required to try Pithos — you only connect a Sia account when you want to actually store files.

Sia is radically cheaper for large storage: roughly $1–$2 per TB per month, versus $10/mo for Dropbox's 2 TB plan and $10/mo for Google One's 2 TB plan. Downloads cost a cent or two per GB (included free in Dropbox and Google). You only pay for exactly what you store, not for a quota tier. For a 500 GB personal backup, Pithos + Sia runs about $0.50–$1/mo; the Dropbox or Google equivalent is $10/mo. Full side-by-side on the comparison page.

Yes. Every file is split, encrypted and spread across many independent Sia hosts before it leaves your machine. No single host sees your file, no host knows who you are, and nobody — including Silent Mode and the Sia Foundation — holds a key that could decrypt your data. The encryption key is derived from your Sia account and never leaves your computer.

Yes if you want sovereignty and cheap storage, with trade-offs. You get: your own data, no corporate account tracking you, prices 5–10× cheaper for large storage, S3-compatible access so every S3 app works. You give up: sync-across-many-devices (today Pithos is single-machine; a sync client is on the roadmap) and collaborative real-time editing. For backup, personal archive, media libraries, website hosting, or anything you'd put on an external drive — Pithos is a direct upgrade.

No. Pithos itself installs with no account at all. The Sia storage underneath is paid through a Sia indexer; several indexers accept crypto only and ask for no personal information. If you prefer, some accept cards — but it's not a requirement for using the software.

No. Pithos is a control panel. Your data goes from s3d on your machine straight to Sia hosts, paid through your indexer account. Silent Mode never sees or holds your files.

v0.2.0 or newer. Pithos offers to install the right one for you and tells you when yours is too old.

Yes. Pithos uses the same config file a hand-run s3d uses. If s3d is already running, Pithos shows it as external, reads its stats and leaves the process alone.

The Sia account (for example on sia.storage) pays for the space; your s3d is connected to one. S3 users are logins on your own s3d, each with its own access keys, so you can give an app its own key and revoke it alone. A drive is top-level storage owned by one user, like a disk on your computer; S3 apps call it a bucket. Folders and files go inside drives.

Yes, under Sia connection › Switch Sia account. s3d connects to the new account and starts empty. The previous account keeps its files, and its users, keys and drives are set aside on your computer so you can restore them later. Pithos warns you first if uploads are still on their way to Sia.

After three wrong tries Theseus asks for your master password, which always works. You can set a new PIN any time in Theseus Settings › Passwords.

Not yet. s3d can make a whole drive public for reading, but not one folder, and it cannot give other people rights to add or change files. Keep public files on a drive of their own, and send a share link for a single file.

Uploads from the Pithos window are capped at 5 GiB per file for now. S3 clients such as aws and rclone use multipart uploads and go well beyond that.

A pithos was the great storage jar of the ancient Greek world, where a household kept what it could not afford to lose.