Chance.js vs Snowfakery
Chance.js
chancejs.comSnowfakery
snowfakery.readthedocs.ioSide by side
| Figure | Chance.js | Snowfakery |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | — |
| Linux | — | Yes |
| API | Yes | Yes |
| Self-hosted | — | Yes |
| Plans published | 1 | 1 |
| Spec score · Test Data Generation Tools | 8.3 (#2) | 7.9 (#8) |
| Intended users | The site gives generating random names and addresses for automated tests as an intended practical use. | The documentation describes installation paths for Salesforce users and for users who want to use Snowfakery without Salesforce. |
| Purpose | Chance generates pseudo-random strings, numbers, and other values for automated tests and other uses that need random data. | Snowfakery generates unique, random fake data with relationships between tables from YAML recipe files. |
Plans
In their own words
Chance.js
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.
Snowfakery
Snowfakery generates synthetic data from YAML recipe files, including records linked across tables. Recipes can create names, addresses, text, URLs, random numbers and other values using Faker-based functions, and specify how many related objects to generate. Output can go to files in JSON, TXT, CSV, SQL, DOT, SVG, SVGZ, JPEG and PostScript formats; some diagram formats require Graphviz. Snowfakery can also write to databases accessible through SQLAlchemy, including SQLite, and generate records in Salesforce when used through CumulusCI. Python applications can embed it with its generate_data function, and Python plugins and providers can extend its functions and Faker capabilities. Strict mode checks a recipe before generation, while validate-only mode checks it without generating data. It is free, open source and self-hosted. The documentation says database output creates new tables, with generated columns as text, and that SQLite is the only database included in its SQL dataset URL test suite. The repository was archived on September 18, 2026, and is read-only.