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Blockchain-anchored · Privacy-first

Prove your document was never changed.

Signim creates a tamper-proof certificate the moment you upload — sealed permanently on the blockchain so any dispute has a clear, undeniable answer.

No account needed
Files never leave your device
Takes 60 seconds
Certificate of Integrity Verified
Engagement_Letter_2026.pdf
Certified Apr 6, 2026 · 14:32 UTC
SHA-256 Fingerprint
a3f2c91b4e8d0f1a…7b2c9e4d8f1a6e3c
d9f3a12b8c4e7a0f…1b6d3e9a2c5f8b0d
TimestampApr 6, 2026 · 14:32 UTC
Status✓ Anchored
Privacy✓ File never uploaded
Trusted by professionals in
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0 documents certified and counting
How it works

Three steps to permanent proof

Your file never leaves your device. We hash it client-side and anchor that fingerprint to the blockchain — permanently.

Step 01

Upload a file or paste a URL

Choose any file — PDF, Word, image, audio, video — or paste any URL. Processed entirely in your browser. Nothing sent to our servers.

Step 02

We generate a permanent fingerprint

A cryptographic hash is created and anchored to the Constellation Network blockchain — immutable, decentralized, and tamper-proof forever.

Step 03

Share your verify link as proof

Get a permanent certificate link you can share with clients, courts, or colleagues. Anyone can verify — no account needed.

Certify your first document free

No account needed. Your file never leaves your device. Takes 60 seconds.

Drop a file or click to browse PDF, Word, image, ZIP — any format

Audio & video fingerprinting — your media file is hashed entirely in your browser. Only the fingerprint is sent. Files up to 2GB supported.

Drop audio or video file MP3, WAV, MP4, MOV, AVI — any format
Files never stored Permanently anchored Free to start
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Why Signim

Built for professionals who need proof

Every certificate is permanent, shareable, and verifiable by anyone — no account required to verify.

Privacy by design

Files are hashed in your browser. Only the fingerprint ever leaves your device — we never see your content.

Blockchain-anchored

Every fingerprint is permanently recorded on Constellation's DAG — immutable, decentralized, verifiable forever.

Instant shareable proof

A permanent certificate link you can share with anyone. Anyone can verify — no account needed.

Takes 60 seconds

No setup. No integrations. Upload and your certificate is live on the blockchain in under a minute.

Any file, any format

PDFs, Word docs, images, audio, video — if you can upload it, Signim can certify it.

URL fingerprinting

Certify any web page as it exists right now. Preserve news articles, contracts, or any online content permanently.

Healthcare professionals Law firms Freelancers Landlords Journalists Accountants & CPAs HR teams Real estate Anyone who needs proof
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