How it works & FAQ
Capsule is a free anonymous file transfer tool with no logins, no accounts, and no personal information collected. Send any file from your browser or the command line and get a shareable link back in seconds. Files automatically delete after 60 minutes.
Getting started
How do I send a file with curl?
One command. You get a short download link back immediately.
curl -F "f=@photo.jpg" https://send.withcapsule.dev/upload
How do I send a file from the browser?
Go to withcapsule.dev, click the Send tab, choose your file, and hit Send. You'll get a short link and a QR code you can share or scan immediately.
How does the recipient download the file?
Share the link or QR code with them. They open it in a browser (or use curl as shown here) and the file downloads directly, no account needed on their end either.
curl -O https://send.withcapsule.dev/<file-id>
Limits & specs
What is the maximum file size?
100 MB per file.
How long do files stay up?
60 minutes from the time of upload. After that the file is automatically and permanently deleted.
Is there an upload rate limit?
2 GB per hour per uploader. This keeps the service free for everyone.
What file types are supported?
Any file type. There are no restrictions on file format.
Privacy & security
Do I need an account or login?
No. Capsule requires no account, no email, and no personal information of any kind. Just upload and share.
Is my file transfer private?
Files are stored temporarily and deleted automatically after 60 minutes. No personal data is collected. Analytics are only on the web interface, and handled by Plausible, a privacy-friendly tool that does not use cookies or collect personal identifiers.
Does Capsule support encrypted file transfer?
Yes. The web interface has a built-in Encrypt checkbox on the Send tab. When checked, the file is encrypted entirely in your browser before upload using the age v1 format. The server never sees your key or the original file. After upload, you receive a 12-word mnemonic phrase; the recipient enters it on the Receive tab to decrypt.
The CLI's upload-encrypted subcommand
and Android app work the same way. All three clients
produce compatible age v1 ciphertext, so a file
encrypted on the web can be decrypted in the CLI and
vice versa.
CLI & advanced use
Is there a CLI tool?
Yes. The Capsule CLI supports encrypted file transfer, local history, and self-hosting options, more than what the web interface offers.
Can I self-host Capsule?
Yes, the documentation has instructions on how to host the Capsule Server and configure the CLI to point to it.
Is the service down?
Check uptime.withcapsule.dev for live status and incident history.
Who built this?
Capsule was built by Sean Singh. Read about the motivation and design decisions on the blog →