Just upload what you already have — photos, audio, video, notes, or a chat screenshot — and its SHA-256 hash is anchored to the Bitcoin blockchain. We don't vouch for the truth of the content, but we do preserve, in a form anyone can independently verify later, the fact that this exact data existed at this exact moment.
Instead of storing your file's content long-term on a server, we anchor its "trace" into Bitcoin's tamper-proof ledger.
Just pick a file — a photo, recording, video, or note. It's hashed with SHA-256 on the spot and handled separately from the original data.
The hash is submitted to the Bitcoin blockchain via multiple calendar servers to build the proof.
Download the original file, the .ots proof file, and a verification report anytime — anyone can verify them independently.
Not a tool for public shaming or viral call-outs — a record to protect yourself and prevent "he said, she said" disputes later.
Timestamp a screenshot of a verbal or chat agreement at the moment it was made.
Objectively record when a proposal or design was completed, ahead of any later ownership dispute.
Preserve a recording or message thread, unaltered, together with the date and time.
How to document workplace harassment →Prove the state of a deliverable at handoff, ahead of any later "it was never delivered" claim.
Why freelancers should timestamp deliverables →Record a rental unit's condition at move-in, ahead of any later dispute over restoration costs or deposits.
Protect your security deposit →For frontline and service staff: record and preserve abusive complaints or verbal abuse.
Documenting abusive customers →Record when a design or prototype was developed, ahead of any later prior-use-rights dispute.
Proving you had the idea first →Record the condition before and after work, ahead of any "that damage was already there" dispute.
Before-and-after photos protect you →Record a vehicle's condition for accidents, hit-and-runs, rental returns, or used-car sales.
Documenting vehicle condition →Certificate issuance is completely free on the Free plan. Choose based on storage and audio/video support.
This service does not verify or guarantee the truthfulness of any uploaded data's content. It functions as a mechanical timestamping infrastructure that objectively records, in a form independently verifiable by third parties via the Bitcoin blockchain, the fact that a given piece of data existed at a given point in time.