Chance.js vs Tonic Fabricate
Chance.js
chancejs.comTonic Fabricate
tonic.aiSide by side
| Figure | Chance.js | Tonic Fabricate |
|---|---|---|
| Price from | Free | $29/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | — | Yes |
| Plans published | 1 | 3 |
| Spec score · Test Data Generation Tools | 8.3 (#2) | 7.7 (#13) |
| Founded | 2013 | 2018 |
| Integrations | The documentation includes installation and usage instructions for Bower and RequireJS, as well as npm for Node.js. | The product page lists PostgreSQL, MySQL, Oracle, Databricks, Snowflake, SQL Server, MongoDB, Amazon S3, Avro, Iceberg, and Parquet among its connections and export formats. |
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.
Tonic Fabricate
Tonic Fabricate uses a conversational AI agent to create synthetic data for databases, APIs, and files. It targets product development, software testing, AI model training, reinforcement learning environments, and sales demos. Generated content can include relational records, JSON, PDFs, DOCX files, and emails, with domain details and relationships preserved. An optional Validation Agent reviews output and prompts refinements. Fabricate can create mock APIs from uploaded specifications and define workflows callable through an API; its MCP supports generation from compatible clients such as Claude and Cursor. Listed connections and formats include PostgreSQL, MySQL, Oracle, Databricks, Snowflake, SQL Server, MongoDB, Amazon S3, Avro, Iceberg, and Parquet. Free costs nothing and lists $5 in monthly credits; Plus costs $29 a month with $25 in credits. Enterprise has custom pricing and offers Tonic Cloud or self-hosting. Tonic says synthetic records can reduce exposure to real sensitive data and support GDPR and HIPAA compliance.