KeySense
Crypto key math is confusing. KeySense makes it visible: derive and inspect keys across nine chains and two curves, print a branded A4 paper wallet for cold storage, mine vanity EVM addresses, and see exactly how a passphrase turns into a wallet.
It runs entirely in your browser, with zero network requests, so it works fully air-gapped on an offline device.
What it is
Most wallets hide how a seed phrase becomes an address. KeySense covers nine chains: Bitcoin, Ethereum and EVM chains, Solana, Tron, Litecoin, Dogecoin, Cosmos, Sui, and Aptos. Different wallets also use different derivation paths for the same coin, so restoring the same seed phrase into a new wallet can show a $0.00 balance even though the funds are still there, just at a different path. The app has a live side-by-side demo of exactly this: the same seed, Legacy versus Native SegWit, two different addresses computed on the spot.
KeySense derives keys across two curves: secp256k1 for Bitcoin, Ethereum and EVM chains, Tron, Litecoin, Dogecoin, and Cosmos; Ed25519 via SLIP-0010 for Solana, Sui, and Aptos. Bitcoin's four script types sit side by side, including a real BIP86 Taproot implementation verified against all three official test vectors, so a path mismatch is visible instead of hidden.
Everything runs client-side, on every chain, including Solana, Sui, and Aptos, which used to need a local server and now work straight from a file on disk. No seed, key, or passphrase is ever sent over the network, so it runs fully air-gapped on an offline machine.
What you get
- Derivation engine
- Multi-chain, multi-curve derivation across nine chains: Bitcoin (Legacy, Wrapped SegWit, Native SegWit, and a real BIP86 Taproot), Ethereum and EVM chains, Solana, Tron, Litecoin, Dogecoin, Cosmos, Sui, and Aptos (secp256k1 and Ed25519 via SLIP-0010)
- Expert mode
- Extended key engine (XPUB/XPRV) at account root and leaf nodes, relative child derivation from a pasted xpub/xprv, a four-column Bitcoin UTXO matrix (Legacy, Nested SegWit, Native SegWit, Taproot), and batch generation of up to 50 sequential addresses
- Vanity address miner
- Offline EVM address mining by prefix, suffix, or contains pattern, entirely in-browser, with a live hash-speed counter and difficulty estimate
- Brain wallet lab
- SHA-256 entropy hashing from a passphrase into a 24-word BIP39 mnemonic. The strength check is a live comparison against a generated seed's 128 bits, deliberately never a pass or fail score: known phrases like 'correct horse battery staple' read zero bits regardless of length, because no typed phrase is ever safe for real funds
- Blockchain guide
- Fifteen clickable chain rows that load the preset and derive a real address from your loaded seed, plus the reasoning behind each one: why every EVM chain shares coin type 60, why Bitcoin varies purpose instead of coin type, and what an xpub actually leaks on its own versus with one child key
- Learn Paths walkthrough
- Five steps computed live from your own seed, down to the real PBKDF2 seed, its HMAC-SHA512 split, and the same index derived hardened versus normal side by side. The access-scope exercise recovers a real parent private key on screen from an xpub plus one leaked child key, using the actual BIP32 math, then confirms it against the true key
- Experiments (alpha)
- A path-recovery scanner that matches a known address against common derivation paths, and mnemonic diagnostics that find a typo or a missing final word in a 12 or 24-word phrase
- Execution
- One hundred percent client-side, on every chain, including Solana, Sui, and Aptos, which now work fully offline too. Dependencies are vendored and SHA-384 hash-verified with a reproducible build script, and a runtime entropy canary checks the browser's random source before anything trusts it. Zero network requests, no backend, no tracking
Common questions
Does KeySense ever send my seed phrase or private keys anywhere?
No. Everything runs client-side in your browser. There are zero network requests, so it works fully air-gapped on an offline device.
Why did my wallet show a $0.00 balance after I restored my seed phrase?
Different wallets often use different derivation paths for the same coin, for example m/44'/60'/0'/0/0 versus m/44'/60'/0'/0. A path mismatch shows an empty wallet even though the funds are still there, at a different path. KeySense lets you check a seed against multiple paths at once.
Is KeySense a wallet?
No. It does not hold funds and does not connect to any network or exchange. It is a derivation, address-mining, and education workbench.
How random is the seed, really?
Generated seeds come from the browser's CSPRNG, the same OS-level hardware entropy source real wallets use, not Math.random. A runtime canary checks that source is not returning degenerate output before anything trusts it, a comparison panel with an attacker-speed slider shows why 128 bits holds up, and Learn Paths cites the July 2026 Coldcard hardware wallet failure, where a bad RNG silently cut 128 bits of entropy down to as little as 40 for five years before it was caught.
Which chains and curves does it support?
secp256k1 for Bitcoin, Ethereum and EVM chains, Tron, Litecoin, Dogecoin, and Cosmos. Ed25519 via SLIP-0010 for Solana, Sui, and Aptos.
Is the code open source?
The source is public on GitHub, free to download and use for any purpose including commercial. It is source-available rather than OSI open source: modifying, rebranding, or redistributing a changed copy needs the copyright holder's permission.
KeySense is a derivation, address-mining, and education tool. It is not a wallet: it does not hold funds and does not connect to any network or exchange. Brain wallets are shown for education only; use standard BIP39 entropy for real funds. Never enter a seed you use for real funds into a device you do not fully control.