How does ProtonURL encryption work?

Encryption happens entirely in your browser using AES-256-GCM. The decryption key is stored only in the URL fragment (#k=...), which is never sent to our servers. We only ever receive encrypted ciphertext — we cannot read your content even if we wanted to.

What does one-time read mean?

When the link is opened, the encrypted content is retrieved, decrypted in the browser, displayed once, and then permanently deleted from our servers with a signed ECDSA deletion proof. The link cannot be used again.

Do I need an account to use ProtonURL?

No. Anonymous links work without registration. Creating a free account gives you access to additional features like API access, a link management dashboard, and higher usage limits.

What file sizes are supported?

File attachments are supported on all plans. Free plan: up to 10MB per file. Paid plans: up to 10MB (Starter/Pro) or 30MB (Business) per file. Files are encrypted the same way as text content.

How does the API work?

API plans give you an API key to create and manage encrypted links programmatically. You POST your content to our encryption endpoint, we return a one-time link. The API is REST-based and works with any HTTP client.

Zero-knowledge · One-time read · No account required

Share secrets that self-destruct after one read

ProtonURL encrypts your sensitive information end-to-end and gives you a link that permanently destroys itself the moment it is read. Passwords, API keys, contracts — shared safely over any channel.

AES-256-GCM encryption in your browser — servers can never read your content
One-time read: the link burns itself after the first view
Optional encrypted file attachments up to 10MB
Verifiable ECDSA deletion proof for every burned link

Create a secure link View pricing

Create an encrypted link

AES-256 end-to-end

Secret content Custom passphrase (optional)

The passphrase is never sent to our servers. If you lose it, the content cannot be recovered.

File attachment (optional, max 10MB)

Click or drag a file here to attach

How it works

Enter your secret

Paste the sensitive content, add a passphrase or a file if you like.

Encrypted in-browser

AES-256-GCM encryption happens on your device. We only ever receive ciphertext.

Share the link

Send the one-time link over email or chat. Without the exact link, nobody can decrypt it.

Read once, gone forever

After the first read the content is permanently destroyed with a signed deletion proof.

Simple, honest pricing

Free forever for personal use. API plans when you automate.

Free

End-to-end encrypted sharing for everyone

$0 forever

Unlimited encrypted links
One-time read & auto-destroy
ECDSA deletion proofs
10MB file attachments
No account required

Start for free

API Starter

Automate secret sharing via the REST API

$4.99 /month

100 API-created links / month
REST API access
1 API key
One-time read & auto-destroy
Deletion proofs

Get API Starter

API Pro

For developers and small teams

$10.99 /month

300 API-created links / month
REST API access
5 API keys
10MB file attachments
Deletion proofs
Priority support

Get API Pro

API Business

Maximum volume and larger attachments

$24.99 /month

1,000 API-created links / month
REST API access
Unlimited API keys
30MB file attachments
Deletion proofs
Priority support

Get API Business

Stop sending secrets in plain text

Create your first encrypted, self-destructing link in seconds. No sign-up required.

Create a ProtonURL for free