Sequelize
A Node.js and TypeScript ORM for working with SQL databases using JavaScript objects.
- Stars
- 30.3k
- Forks
- 4.5k
- Licence
- MIT
- Language
- TypeScript
- Last update
- 5 days ago
- Type
- Library
What it is
Sequelize is an object-relational mapper (ORM) for Node.js. It lets developers read and write rows in SQL databases such as PostgreSQL, MySQL, MariaDB, SQLite and Microsoft SQL Server through JavaScript or TypeScript code instead of hand-written SQL. The README describes it as promise-based, with transaction support, relations, eager and lazy loading, and read replication.
- Define models for tables and query them with promise-based methods
- Group several database writes into a transaction so they succeed or fail together
- Declare relations between models and load related records eagerly or lazily
- Send reads to replica servers using read replication
Great for
- Node.js backend developers who use a relational SQL database
- TypeScript teams that want typed database models
- Projects that may switch between PostgreSQL, MySQL, SQLite or MSSQL
- Developers who want transactions and relations without writing raw SQL for every query
Not ideal for
- Projects that don't use a SQL database, since Sequelize is built for relational databases
- Developers who prefer writing raw SQL and want minimal abstraction
- Teams that need a stable release right now, since the README highlights active work on the next major version and links to a v7 alpha guide
How to get it
- 1
Install with a package manager
You'll need: Node.js · A supported SQL database such as PostgreSQL, MySQL, SQLite or MSSQL
Install the core package (from the npm badge link)
npm install @sequelize/core - 2
Run it
- Install the package with npm
- Set up a database connection using the getting started guide at sequelize.org
- Define a model for a table
- Run a query or a transaction against the database
- 3
Get the most out of it
- Follow the official docs at sequelize.org for the version you choose (v6 stable or v7 alpha)
- Use the Sequelize CLI from github.com/sequelize/cli for migrations and project setup
- Check the databases compatibility table on the releases page before choosing a database
- Look at the listed tools such as the GraphQL and CockroachDB integrations if they match your stack
Downloads
Strengths
- Supports many SQL databases, including PostgreSQL with JSON and JSONB support
- Written in TypeScript and published under the permissive MIT license
- Has a long history, a large star count and an active contributor community
Trade-offs
- The README asks for new maintainers and notes that the next major version is still being finalized
- Two major versions are documented (v6 stable, v7 alpha), so users must pick one and follow its guide
- Feature details beyond the README summary are not covered in the text provided
How it compares
| Project | Stars | Type | Level | Updated | Best for |
|---|---|---|---|---|---|
| sequelize (this) | 30.3k | Library | intermediate | 5 days ago | Node.js backend developers who use a relational SQL database |
| typeorm | 36.7k | Library | intermediate | 8 days ago | Node.js or TypeScript developers building apps backed by a relational database |
| sqlc | 18.4k | Dev tool | intermediate | 4 days ago | Go developers who prefer writing plain SQL over using an ORM |
| usql | 10.2k | CLI | beginner | 4 days ago | Developers who use several different databases and want one tool for all of them |
| kysely | 14.3k | Library | intermediate | 4 days ago | TypeScript developers who want SQL control without losing compile-time type checks |
| knex | 20.3k | Library | intermediate | 4 months ago | Node.js developers who need to talk to a SQL database from application code |
Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.