SolAnchor — Timestamp anything on Solana

1

What are you anchoring?

Only the hash goes on-chain — your data never leaves this browser.

SHA-256, Keccak-256 or any short string

2

Sign & broadcast

Sign with a USB Ledger / Trezor, a browser wallet, or a devnet burner.

Network: Devnet
Fee payer: not connected
Balance: —
Program: MemoSq4g…DLGmfcHr
Est. cost: 0.000005 SOL

✓

Verify an anchor

Look up a transaction and read its timestamp straight from the chain.

Transaction signature Expected hash (optional — check a hash or file against it)

How verification works

We fetch the confirmed transaction from a Solana RPC node.
The block time is the validators' consensus timestamp — that's your proof.
The memo is compared with your hash; a single changed bit gives a mismatch.

Tip: anyone can verify — share the link from your receipt.

Anchors

Saved on the server and checked on-chain. Export them — they're your receipts.

contract-final.pdf

SHA-256 · 64 characters

BLOCK

YOUR ANCHOR

✔ Anchoredslot

How it works

Prove it existed.

Scroll to watch a file become permanent proof on Solana.

Scroll ↓

01 · Fingerprint

Your file becomes 64 characters.

SHA-256 runs right in your browser. Change one byte and the fingerprint changes completely. The file itself never leaves your device.

02 · Anchor

Locked into a Solana block.

One small transaction writes the fingerprint into the chain. You approve it in your wallet, no tokens move, and the fee is about 0.000005 SOL.

03 · Prove

Timestamped. Forever.

The block time is public and permanent. Anyone can check it, and nobody can change it, not even you.

Your turn

Make your first proof.

Try it free on Devnet, or go permanent on Mainnet.

Anchor something Verify a proof

FingerprintAnchorProve

The details

What to keep

The original file, unchanged. Changing even one character gives a completely different fingerprint.
The transaction signature. It's on your receipt and in History. It points to your proof.
A backup. Use Export in History to save your receipts as a JSON file.

What people use it for

Creative work: show that your design, code, music or writing existed first.
Agreements: prove a contract or document hasn't been edited since that date.
Records: research data, logs, screenshots and evidence.
Releases: publish a build's hash so anyone can check their download.

Connecting a wallet

Browser wallet: Phantom, Solflare or Backpack.
Ledger or Trezor: plug in over USB, no extension needed (Chrome, Edge or Brave). On a Ledger, open the Solana app. Each anchor needs a button press on the device.
Phone wallet: choose WalletConnect and scan the QR code.
Just trying it out? Use the free Devnet burner wallet. It lives in this browser and only works on Devnet.

Devnet or Mainnet?

Devnet is a free test network. Use it to learn how everything works. Don't rely on it for real proof, because test networks can be reset.
Mainnet is the real Solana network. It costs a tiny amount of real SOL and the record is permanent. Use it for anything you may need to prove later.

Questions

Can anyone see my file?

No. Only the fingerprint is public, and a fingerprint can't be turned back into the file. One exception: very short or predictable text (like "yes" or a date) can be guessed by trying options. For text like that, add a random word or number first.

Does this prove I'm the author?

It proves the content existed at that moment and shows which wallet anchored it. That is strong evidence, but on its own it isn't proof of ownership.

Can an anchor be deleted or changed?

No. Solana transactions are permanent. Removing an item from History only hides it from the list here. The on-chain record stays.

I edited my file. Is my proof gone?

Your old proof still covers the old version, as long as you have a copy of it. The edited file has a new fingerprint, so anchor it again if you want proof for that version too.

Do I need to trust this website?

No. The proof lives on Solana, not on this server. Anyone can check the transaction on Solana Explorer, and anyone can hash the file with any SHA-256 tool and compare the result.

For developers: command line

Run these from the SolAnchor project folder.

node hash/anchor-solana.js --hash <hex> --cluster devnet

node hash/anchor-solana.js verify <SIGNATURE>

npm run solana # interactive menu

Prove it existed.Timestamp anything on Solana.

What are you anchoring?

Sign & broadcast

Verify an anchor

How verification works

Anchors

Prove it existed.

Your file becomes 64 characters.

Locked into a Solana block.

Timestamped. Forever.

Make your first proof.

The details

What to keep

What people use it for

Connecting a wallet

Devnet or Mainnet?

Questions

For developers: command line

Prove it existed.
Timestamp anything on Solana.