Public proof for file hashes

Timestamp a file. Keep it private.

nStamp calculates a SHA-256 hash in your browser and writes only that fingerprint to NEAR. The public record lets anyone confirm that matching file bytes existed no later than the block time.

nStamp your file See how it works
SHA-256 in browser File never uploaded Public NEAR timestamp Independent checking

Proof receipt

Hash publicly timestamped

SHA-256 fingerprint 7d9f…a42c
  1. Hash in browserFile stays on device
  2. Only hash sentFingerprint, not file
  3. Recorded on NEARPublic, time-bound commitment

Why it matters

Files change. A public timestamp does not.

nStamp creates evidence that particular file bytes existed no later than a recorded block time. It does not prove who created the file, whether its contents are true, or whether it was complete. Those claims still depend on the surrounding evidence.

How it works

Hash. Anchor. Verify.

Three steps from a private file to a public, independently checkable timestamp.

01

Hash in browser

Drag in a PDF, image, dataset, code archive, or creative draft. nStamp calculates the SHA-256 fingerprint locally in your browser, so the file stays on your device.

02

Anchor on NEAR

Sign a transaction that writes only the SHA-256 fingerprint to NEAR. The record is public, timestamped, and tied to the stamping account.

03

Verify anywhere

Anyone with the file can calculate its hash and compare it with the public record. A match confirms that the file has exactly the bytes committed to at that time.

Who needs it

Useful wherever trust needs evidence.

⚖️

Legal professionals

Create a timeline for research, drafts, evidence packages, and AI-assisted work.

🎨

Creators & artists

Timestamp sketches, layers, drafts, and releases to document when each exact version existed.

🤖

AI developers

Timestamp outputs, prompts, model artifacts, and evaluation records without exposing private files.

🔬

Researchers

Stamp datasets, methods, preprints, and milestones to create a verifiable trail.

Privacy model

Private file. Public hash.

nStamp does not upload or store your file. The hash is calculated in your browser, and only the fingerprint is written to the public blockchain.

Open the app →
Browser hashingFile stays on your device
SHA-256Deterministic file fingerprint
NEARLow-cost public timestamp
Independent checkingRecalculate the hash and inspect the public record

Start now

Create a public timestamp for your file hash.

Your browser creates the hash. NEAR records the commitment. Your file stays with you.

Try nStamp

FAQ

Simple answers for normal people.

Do my files go on-chain?

No. Your browser calculates a SHA-256 hash locally. The public record is the fingerprint of the file, not the file itself.

What exactly does a stamp prove?

It proves that a particular SHA-256 hash was committed to a public NEAR record no later than the recorded block time. A matching file has exactly the bytes represented by that hash.

What does a stamp not prove?

A stamp does not prove authorship, ownership, accuracy, legality, or that the file tells the truth. Use the stamping account and other evidence to support those wider claims.

Can someone verify without trusting nStamp?

Yes. Verification works by hashing the original file again, in the browser or any SHA-256 tool, and comparing the result with the blockchain record.

Do I need a NEAR account?

You need a NEAR wallet to create a stamp. Anyone can recalculate a SHA-256 hash and inspect the public record without connecting a wallet. You can set up a NEAR account at near.com.