according to this link, I want to convert mnemonic words to its corresponding seed. I want to do this by javascript and use it in webclients without nodeJS.
the library that I have in mind is cryptoJS.
I am planning to use function pbkdf2, but I don't know which js file I need to add to html page.
I have one old answer here how to use cryptoJS: https://stackoverflow.com/a/43438494/2951051
About your last question " which js file I need to add to html page.":
I use this scripts from gitHub: https://github.com/sytelus/CryptoJS
After that I use this files from rollups/ folder:
aes.js , pbkdf2.js, hmac-sha512.js
For more random entropy i have changed random.js (inside aes.js) with another random function you can download from : https://github.com/wwwtyro/cryptico/blob/master/random.js