ProtonURL is a zero-knowledge secret sharing service. You paste sensitive text (passwords, API keys, private notes), it gets encrypted in your browser with AES-256-GCM, and you get a one-time link. When the link is opened once, the content is permanently destroyed.
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.
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.
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.
Free plan: unlimited encrypted links via web. API Starter ($4.99/mo): 100 API-created links/month. API Pro ($10.99/mo): 300 API-created links/month. API Business ($24.99/mo): 1,000 API-created links/month.
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. See our API documentation for details.
Log in and go to Settings or Profile, then click "Cancel my subscription". Your plan stays active until the end of the current billing period. No further charges will be made.
Due to the immediate digital delivery nature of our service, subscription fees are generally non-refundable except in specific circumstances. Please see our Refund Policy for full details.
The encrypted content is permanently deleted immediately after the first read. We generate a cryptographically signed deletion proof (ECDSA) that anyone can verify to confirm the content was truly destroyed and not retained.
Yes. When creating a link, you can add an optional passphrase. Recipients need both the link URL and the passphrase to view the content. The passphrase is also never sent to our servers.
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.
ProtonURL uses standard AES-256-GCM encryption implemented in well-established cryptographic libraries. Key derivation uses PBKDF2 with 310,000 iterations per OWASP recommendations. Contact us if you have specific security questions.