PostStamper

Blockchain-verified timestamps for your social media posts using OpenTimestamps

As of June 2026, PostStamper has 2 users in the Productivity category.

Usersup 100.0 percent+100.0%
2
2
Ratingno change0%
— reviews
Reviewsno change0%
Version
1.4.0
Manifest V3

History

5 snapshots

Tracking since Apr 1, 2026.

2.081.50.9199999999999999Apr 1, 2026Jun 9, 2026
View as table
DateUsersRatingReviewsVersion
Apr 1, 202611.4.0
Apr 16, 202621.4.0
Apr 26, 202621.4.0
May 13, 202621.4.0
Jun 9, 20261.4.0
Now21.4.0

Permissions & access

Permissions
storagealarmsactiveTabnotifications
Host access
https://alice.btc.calendar.opentimestamps.org/*, https://bob.btc.calendar.opentimestamps.org/*, https://finney.calendar.eternitywall.com/*, https://twitter.com/*, https://x.com/*, https://claude.ai/*, https://chat.openai.com/*, https://chatgpt.com/*, https://www.youtube.com/*, https://youtube.com/*, https://studio.youtube.com/*, https://www.facebook.com/*, https://facebook.com/*, https://www.instagram.com/*, https://instagram.com/*, https://www.linkedin.com/*, https://linkedin.com/*

Screenshots

PostStamper screenshot 1PostStamper screenshot 2PostStamper screenshot 3

About

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.

Technical

Version
1.4.0
Manifest
V3
Size
63.16KiB
Min Chrome
88
Languages
1
Featured
No

Metadata

ID
eibpfjfbhpfgfineikinhlojgfnddnli
Developer ID
ue9ab211e33f3525b70746faea3ad736c
Developer Email
[email protected]
Created
Jan 11, 2026
Last Updated (Store)
Jan 11, 2026
Last Scraped
Jun 9, 2026

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Data sourced from the Chrome Web Store · last verified Jun 9, 2026.