Before you upload
Enable end-to-end encryption before starting the transfer. Astral encrypts each file in authenticated chunks in your browser; the service stores ciphertext rather than readable file bytes or names.
Note: Encrypted uploads currently support files up to 100 MB each. Keep the upload tab open until every encrypted chunk is complete.
Share the complete link
The decryption key is encoded after the # character in the share URL. Browsers do not send that fragment to Astral, so the recipient needs the complete link to decrypt locally.
- Do not remove or rewrite the URL fragment.
- Use a trusted channel to send the complete link.
- If the fragment is lost, Astral cannot recover the key or decrypt the file.
Understand the tradeoffs
Server-side previews, malware scanning, and restart recovery cannot inspect or reconstruct end-to-end encrypted content. Recipients should still verify the sender and keep operating-system security checks enabled.