Schrodinger's Wallet checker
Updated August 2026
Until you spend from a legacy or SegWit Bitcoin address, its public key exists in a kind of superposition: known to you, but not yet visible on the chain. Paste an address below to see which state yours is in.
Check an address
This looks up your address's public transaction history via a public block explorer (blockstream.info). Addresses are public blockchain data by design, this isn't a private key or seed phrase, but do know a real network request is made, unlike the fully offline tools you'll find on other sites we run.
Why "exposed" matters here
Bitcoin addresses don't contain public keys directly, for the older formats. A P2PKH or SegWit address is built from a hash of your public key, and the key itself only gets revealed on-chain at the moment you spend from that address, since a valid signature has to include it. Until then, an attacker (quantum or otherwise) only sees the hash, and reversing a hash to recover the original key is a completely different, much harder problem than the one a quantum computer would actually be good at.
Taproot changes this. A P2TR address commits directly to an x-only public key, so the key is visible the moment funds arrive, whether you've ever spent or not. That's not a flaw exactly, it's a tradeoff Taproot made for other benefits, but it does put every Taproot address in the more exposed tier immediately.
What "exposed" doesn't mean
It doesn't mean your funds are at risk today. No quantum computer currently in existence, or credibly expected soon, can break the elliptic curve cryptography Bitcoin uses (secp256k1) fast enough to threaten a real address before a defending transaction could be confirmed. Roughly 5.4 million BTC, about a quarter of the total supply, currently sits in this exposed category, mostly from addresses that have simply been used normally over the years. For the full picture on why this matters at all and what's actually being proposed, read our explainer on Bitcoin and quantum computing.
This tool classifies exposure tier based on public on-chain data. It cannot tell you whether any specific attack is feasible, and it isn't security advice for a specific holding. If in doubt about migrating funds to a new address, that's always the simplest, currently-available mitigation regardless of what this tool reports.