Random password generator

A random password generator is a software program or hardware device that takes input from a random or pseudo-random number generator and automatically generates a password.
Mnemonic hashes, which reversibly convert random strings into more memorable passwords, can substantially improve the ease of memorization. As the hash can be processed by a computer to recover the original 60-bit string, it has at least as much information content as the original string.

Websites

Web Cryptography API

The Web Cryptography API is the World Wide Web Consortium’s recommendation for a low-level interface that would increase the security of web applications by allowing them to perform cryptographic functions without having to access raw keying material. The Web Crypto API provides a reliable way to generate passwords using the crypto.getRandomValues method. Here is the simple Javascript code that generate the strong password using web crypto API.

FIPS 181 standard

Many computer systems already have an application to implement the password generator standard FIPS 181. FIPS 181—Automated Password Generator—describes a standard process for converting random bits into somewhat pronounceable "words" suitable for a passphrase. However, in 1994 an attack on the FIPS 181 algorithm was discovered, such that an attacker can expect, on average, to break into 1% of accounts that have passwords based on the algorithm, after searching just 1.6 million passwords. This is due to the non-uniformity in the distribution of passwords generated, which can be addressed by using longer passwords or by modifying the algorithm.

Mechanical methods

Yet another method is to use physical devices such as dice to generate the randomness. One simple way to do this uses a 6 by 6 table of characters. The first die roll selects a row in the table and the second a column. So, for example, a roll of 2 followed by a roll of 4 would select the letter "j" from the fractionation table below.