How do non custodial web wallets work?

[cr4zyd3v]

Lot's of web wallets claiming to be non custodial but how do they do this? they usually create a seed and mnemonic pass..
Do they sign the transaction in-browse then broadcast the signed tx for a external server?

[akhjob]

Lot's of web wallets claiming to be non custodial but how do they do this? they usually create a seed and mnemonic pass..
Do they sign the transaction in-browse then broadcast the signed tx for a external server?

I hope you understand the difference between custodial and non-custodial wallets. In short, custodial wallets share your private keys with a third party while non-custodial wallets do not. Therefore, with non-custodial wallets, you have full control over your funds and is more secure.
So, non-custodial web wallets do not share your private keys with others and are generated in your browser. For accessing it, you'll have to enter the private keys, sign the transaction and then broadcast it.

[DaveF]

What akhjob said is correct. The way I usually explain it is, don't think of it as a web wallet. Think of it as a web front end for connecting to a wallet.
But, due to the many browser vulnerabilities don't think of them as secure, just because they are non custodial.

-Dave

[cr4zyd3v]

I see.. was in doubt about where the tx signature did happen..

Also yes.. another day another xss lol. Thanks for clarifying, guys.