Chance.js vs YData Synthetic

Chance.js is a free, MIT-licensed JavaScript library for generating pseudorandom data used in automated tests and other applications needing sample values. Generators cover basic values, text, people, mobile identifiers, web data, locations, dates, finance, helpers, and miscellaneous categories. Developers can install it with npm for Node.js, load it in a browser, or use the separate chance-cli package from the command line. Browser users may create a global instance or instantiate several instances. Supplying a seed makes output repeatable; instances given the same seed can produce the same sequence. Integer generation accepts inclusive minimum and maximum bounds, and the unique() helper builds arrays without repeated generated items. The documented name generator supports English and Italian nationality options. The site lists chance.js at 95KB uncompressed and chance.min.js at 55KB, or 17KB gzipped. Chance is not intended for cryptographic applications requiring true randomness. The site credits Victor Quinn as its writer.

YData Synthetic has no write-up on Specifiction yet; its figures are above.