Getting Started
Quickstart
Sign up, set your passphrase, connect a storage platform you already use, and upload your first encrypted file, in a few minutes.
Free, open source, and yours
zcrypt has no paid tiers, no credit card, and no storage to sell you. You bring your own backend: your encrypted files live in a GitHub, GitLab, Hugging Face, or Telegram account you already have, so your capacity is whatever free space those platforms give you. New accounts also get 1 GiB of shared starter space to try things before connecting anything.Create a free account
Sign up at zcrypt.cloud with your email and a strong account password. If email is set up on the instance, you also get a verification link; verifying it proves the address is yours.
This account password only logs you in. It is not what encrypts your files. That is the passphrase you set next, and the two are intentionally different.
Understand your passphrase
On your first sign-in you create a passphrase. zcrypt uses it to derive your encryption key locally, in your browser. The passphrase and the key it derives never leave your device and are never sent to our servers. That is what makes zcrypt zero-knowledge.
Use at least 10 characters (the app enforces this for new vaults). Choose something strong and memorable, and store it in a password manager. For the full picture of how your key is derived and held, see Core concepts.
There is no passphrase recovery
Because your passphrase never touches our servers, we cannot reset it for you. If you lose it, your files cannot be decrypted by anyone, including us. Save it somewhere safe.Connect a storage platform
zcrypt does not run a storage farm. Your encrypted data lives in a platform account you connect: GitHub, GitLab, Hugging Face, or Telegram. Open Settings and add an access token (or a bot token and channel for Telegram). zcrypt then creates private repositories, or a private channel: on your behalf and stores your encrypted chunks there.
Want more room? Connect more than one platform. For per-platform setup and how tokens are kept, see Connect your storage.
Upload your first file
Open your vault and drag a file onto the explorer, or click to browse. Before anything leaves your device, zcrypt does all of the following in your browser:
- •Splits it into chunks (4, 8, 10 or 16 MiB, tuned to your device).
- •Compresses each chunk with zstd, client-side, so the savings happen before encryption.
- •Encrypts each chunk with AES-256-GCM under a key wrapped by your passphrase, then uploads it to your connected platform.
You see real-time progress as each chunk completes. Only ciphertext ever reaches your storage platform.
Preview or download it
Click the file to open it in the full-screen viewer, images, video, audio, PDFs, documents, and text are decrypted on the fly and rendered locally, with no plaintext leaving your device. Or download it: zcrypt fetches the chunks, reassembles, decrypts, and decompresses them back into the original file on your device.
If your vault is locked, you will be asked for your passphrase once; it then unlocks everything for the rest of your session.