Proof for editable reality

The blockchain seal for the AI age.

Screenshots can be faked. Metadata can be rewritten. Your file never leaves your device. nStamp calculates the SHA-256 hash in your browser and anchors only the fingerprint on NEAR, so anyone can verify it later.

nStamp your file See how it works
Hash in browser File stays on device NEAR timestamp Public verification

Proof receipt

File integrity sealed

SHA-256 fingerprint 7d9f…a42c
  1. Hash in browserFile stays on device
  2. Only hash sentFingerprint, not file
  3. Anchored on NEARTimestamped record

Why it matters

In a digital world, proof is everything.

Deepfakes, AI-generated content, and editable documents make simple claims hard to trust. nStamp gives teams a lightweight way to prove that a file existed in an exact form at a specific time — without sending the file to a server.

How it works

Hash. Anchor. Verify.

Three simple steps from raw file to independent proof.

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 and write only the SHA-256 fingerprint to the NEAR blockchain, creating a timestamped record tied to the stamping account.

03

Verify anywhere

Anyone with the original file can re-hash it and compare the result with the blockchain record. Match means the file was not changed.

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 strengthen proof of authorship.

🤖

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 by design. Verifiable by anyone.

nStamp does not need to read, upload, or store your files. The hash is calculated in your browser, and only the public fingerprint is anchored on-chain.

Open the app →
Browser hashingFile stays on your device
SHA-256Deterministic file fingerprint
NEARLow-cost public timestamp
Public verificationAnyone can re-check the fingerprint

Start now

Make your next important file verifiable.

Stamp the fingerprint, not the file. Your browser creates the hash; NEAR stores the proof.

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 does a stamp prove?

It proves that a file with the matching SHA-256 fingerprint existed at or before the blockchain timestamp, and that the file has not changed since.

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 NEAR account to use nStamp?

For now, yes. We recommend Meteor web app. You can easily get some $NEAR at near.com