Trusted by 10,000+ DeFi users

Understand every crypto
transaction before you sign

DeCypher intercepts transactions and translates complex smart contract calldata into clear, human-readable explanations in real time — powered by a local LLM that never shares your data.

DeCypher Extension

Raw Transaction

0xa9059cbb000000000000000000000000deadbeef... ffffffffffffffffffffffffffffffff

DeCypher Translation

⚠️ Critical Risk: You are granting unlimited spending permission to an unverified contract.

Try DeCypher in Real Time

Paste a transaction or contract to see how DeCypher explains it

Why This Matters

The risks of blind signing are real and growing every day.

Billions Lost to Exploits

Users unknowingly sign malicious contracts, leading to major financial losses.

Blind Signing is Standard

Wallets display unreadable transaction data, leaving users exposed.

Permissions are Dangerous

Unlimited token approvals can silently give full access to your assets.

Clarity Prevents Loss

Understanding transactions before signing is the most effective defense.

The problem with Web3 today

Every day, users lose millions to malicious transactions they didn't understand.

Blind Signing

Most users sign transactions without understanding what they're approving.

Confusing Code

Smart contract calldata is unreadable hex that hides critical details.

Financial Risk

One wrong signature can drain your entire wallet in seconds.

From cryptic to crystal clear

DeCypher transforms unreadable transaction data into plain English explanations you can trust.

Before DeCypher

// Transaction calldata

Function: approve(address,uint256)

// Parameters

spender: 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D

amount: 115792089237316195423570985008687907853269984665640564039457584007913129639935

// What does this mean? Is this safe?

With DeCypher
⚠️

Broad Permission Request

Risk Level: Orange

Action: You are granting unlimited token spending permission.

To: Uniswap V2 Router (Verified ✓)

Token: USDC on Ethereum Mainnet

💡 Recommendation: Consider setting a specific amount instead of unlimited approval.

How it works

Three simple steps between you and complete transaction clarity.

01

Initiate Transaction

You click to sign a transaction in your wallet or dApp — business as usual.

02

Intercept & Decode

DeCypher intercepts the calldata and decodes it using on-chain contract ABIs.

03

Explain & Alert

A local LLM generates a plain English explanation with risk classification.

Color-coded risk alerts

Instantly understand the risk level of any transaction with our intuitive classification system.

Safe

Transaction follows expected patterns with no unusual permissions.

Example:

Standard token transfer to a known address

Expected

Some complexity detected, but within normal DeFi operations.

Example:

Swap on verified DEX with reasonable slippage

Broad

Wide permissions requested. Review carefully before signing.

Example:

Unlimited token approval to a protocol

Critical

High-risk pattern detected. Potential exploit or scam signature.

Example:

setApprovalForAll to unverified contract

For Power Users

More than beginner-friendly

DeCypher isn't just for newcomers. It's built for traders, DeFi power users, and anyone operating in high-stakes environments where understanding every transaction is critical.

Built for Traders

Decode complex multi-step swaps, flash loans, and arbitrage transactions instantly.

DeFi Native

Understand yield strategies, liquidity provisions, and protocol interactions at a glance.

Permission Clarity

See exactly what access you're granting — no more hidden approvals or unexpected delegations.

High-Stakes Ready

Reduce risk in time-sensitive environments where every signature matters.

Complex Transaction Decoded

Transaction Type

Flash Loan Arbitrage

Steps Detected

1Borrow 1000 USDC from Aave
2Swap USDC → ETH on Uniswap
3Swap ETH → USDC on Sushiswap
4Repay loan + 0.09% fee
Profit: ~$12.50 after fees

Built for Privacy and Security

Your data stays yours. Always.

Runs Locally

All transaction decoding happens on your device.

No Data Sharing

Wallet addresses and activity are never transmitted.

No Tracking

No analytics, no history stored, no surveillance.

Aligned with Web3 Principles

Full user control and transparency at every step.

Privacy First

Your keys, your data, your device

DeCypher runs a local LLM directly in your browser. Nothing is ever sent to external servers.

100% Local Processing

All AI inference runs on your device. No cloud APIs, no external servers.

No Data Transmission

Your wallet addresses, transactions, and balances never leave your browser.

Zero Tracking

No analytics, no telemetry, no user profiling. We don't know who you are.

No Storage

Transaction data is processed in memory and immediately discarded.

🔐

Open Source & Auditable

DeCypher's code is fully open source. Verify our privacy claims yourself — inspect every line of code that touches your transaction data.

Compatible with MetaMask, EVM chains, and major DeFi platforms

See it in action

This is what DeCypher looks like when it intercepts a transaction.

DeCypher
Transaction RequestEthereum Mainnet
Contract Interaction
0x1f9...8d4
🦄

Uniswap V3: Router

Verified Contract ✓

⚠️

Broad Permission

Risk Level: Orange

What this transaction does:

• Swaps 0.5 ETH for ~850 USDC

• Slippage tolerance: 0.5%

• Deadline: 20 minutes

💡 This swap uses multiple liquidity pools for better pricing.

Estimated gas:0.0042 ETH (~$8.50)
Learn more about this transaction

Simple, transparent pricing

Start free and upgrade when you need more power. No hidden fees, no surprises.

Free

$0forever

Essential protection for everyday users

  • Basic transaction explanations
  • Risk level classification
  • Common contract detection
  • Local AI processing
  • Unlimited transactions
Most Popular

Pro

$9/month

Advanced insights for serious traders

  • Everything in Free
  • Deep contract analysis
  • Multi-step transaction breakdown
  • Historical pattern matching
  • Custom risk thresholds
  • Priority model updates
  • Advanced DeFi protocol support

Stop signing what you
don't understand

Join thousands of users who now understand every transaction before they sign. Install DeCypher and take control of your Web3 security.

📋 Prototype Notice: This is a near-complete website mockup created for a school assignment.