About SiteWitness
Preserving the web's history with cryptographic proof
What is SiteWitness?
SiteWitness is a tool that lets users capture a permanent, verifiable snapshot of a webpage at a specific moment in time. This service is used by journalists, researchers, and everyday users who need proof that a webpage existed in a particular state.
Unlike traditional screenshots or archives, SiteWitness provides cryptographic proof that the content was captured at a specific time and has not been altered since.
When you capture a snapshot with SiteWitness:
Full HTML Capture
We fetch the webpage and capture its complete HTML content, preserving all text, links, and metadata.
Visual Screenshot
We take a high-resolution screenshot that shows exactly how the page appeared at the time of capture.
Cryptographic Hashing
We generate a SHA-256 hash of all the data, creating a unique fingerprint that proves the content hasn't been altered.
Blockchain Timestamping
Using OpenTimestamps, we anchor your snapshot to the Bitcoin blockchain, providing indisputable proof of when it was captured.
Secure Storage
All snapshots are securely stored with redundant backups, ensuring your evidence is always available when you need it.
The result is a tamper-proof record that can be independently verified by anyone, even if SiteWitness were to shut down in the future.
Journalism
Preserve evidence of online statements before they're deleted or changed
Legal
Document online content for potential legal proceedings
Research
Create verifiable citations of web content
Personal
Keep records of important online information
Business
Document competitor websites, terms of service changes, etc.
Compliance
Maintain records of website content for regulatory requirements