PostStamper

PostStamper - Blockchain Timestamps for Social Media
Create verifiable proof of when you posted content online. PostStamper generates cryptographic timestamps anchored in the Bitcoin blockchain using the OpenTimestamps protocol.
How It Works

Click the stamp button on any supported post
A SHA-256 hash is created locally in your browser
The hash is submitted to OpenTimestamps calendar servers
Within 2-3 hours, your timestamp is confirmed in a Bitcoin block
Download the .ots proof file to verify anytime

Privacy by Design
Your content never leaves your browser. Only the cryptographic hash is sent to timestamp servers—your actual posts, messages, and conversations stay private.

One-click timestamping from any supported page
Separate stamp (your content) and witness (others' content) options
Downloadable .ots proof files
Automatic upgrade from pending to blockchain-confirmed
Export all timestamps as ZIP
Verify proofs against original content
Keyboard shortcuts for quick access

Built on Open Standards
Uses OpenTimestamps, an open-source protocol. Proof files work with any compatible tool and can be independently verified at opentimestamps.org.
No Account Required
All data stored locally. No registration, no tracking, no data collection.