Whit Jackson made one that seems to be created working with HTML/Javascript (GitHub link). He also had an internet site in which you could generate the addresses shopper aspect, but it surely seems to be down now. BTC addresses use Base58 (like Base64 but without the need of related character: https://jaidenamwdl.qowap.com/88848179/the-best-side-of-random-wallet-address-eth