user119689: Many hardware wallets provide the passphrase function that allows you to protect your assets even if your 24 seed phrases are compromised. But I worry that the different companies use different passphrase algorithms. Let's say I store my Bitcoin on Ledger using 24 words + passphrase and 10 years later, Ledger company does not exist. Can I recover my wallet to other hardware wallets?

user88614: Most wallets use the same algorithm, as it is an open standard, BIP-39.
A notable exception is Electrum, which uses a similar, but slightly different mechanism. This is publicly documented and can be reproduced by others.

119689: <p>Many hardware wallets provide the passphrase function that allows you to protect your assets even if your 24 seed phrases are compromised. But I worry that the different companies use different passphrase algorithms. Let's say I store my Bitcoin on Ledger using 24 words + passphrase and 10 years later, Ledger company does not exist. Can I recover my wallet to other hardware wallets?</p>
 88614: <p>Most wallets use the same algorithm, as it is an open standard, <a href="https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki" rel="nofollow noreferrer">BIP-39</a>.</p>
<p>A notable exception is <a href="https://electrum.readthedocs.io/en/latest/seedphrase.html" rel="nofollow noreferrer">Electrum</a>, which uses a similar, but slightly different mechanism. This is publicly documented and can be reproduced by others.</p>
