Overview

SQLDelight keeps SQL as the basis for database access while generating Kotlin APIs from it. Compile-time verification of schemas, statements, and migrations can surface database mistakes before runtime, which is useful for projects where database changes need to remain aligned with application code. It is specifically a Kotlin tool, not a language-neutral generator.

The project is licensed under Apache-2.0 and has no paid tiers. Documented dialects include SQLite, MySQL, and PostgreSQL; HSQL and H2 are experimental, while CockroachDB, DB2, and Oracle dialects are third-party. That makes the first group the clearer starting point, while the experimental and third-party choices call for checking fit before committing.

Key features

Generated Kotlin APIs: SQL statements become typesafe Kotlin APIs, giving Kotlin applications a direct interface to their SQL. Teams working primarily in other languages will not benefit from this central feature.
Compile-time checks: SQLDelight verifies schemas, statements, and migrations, helping catch inconsistencies during development rather than after deployment.
IDE support: SQL autocomplete and refactoring support can make SQL work more integrated with development. The documentation also includes an IntelliJ plugin section.
Migration verification: The Gradle verifySqlDelightMigration task applies migrations to stored schema databases and checks that they reach the latest schema. This is useful for teams that want migration sequences checked as part of their build workflow.
Reactive and platform integrations: The coroutines extension can expose queries as Flow values and emit updated results when queried data changes. Extensions are also provided for RxJava and AndroidX Paging, alongside a Gradle plugin.
JVM connections: The overview covers MySQL and PostgreSQL connections on JVM, with JDBC and R2DBC variants shown for supported dialects. This is relevant for JVM projects, but the connection path still depends on the dialect in use.

Pricing

SQLDelight is free. The free plan is the open-source Kotlin SQL code generation library, and no paid tiers are stated. That makes it viable without a software subscription budget; there are no paid-plan seat counts, quotas, or renewal terms to weigh.

Platforms

SQLDelight supports Android, API, iOS, Linux, macOS, web, and Windows. Its supported language is Kotlin, so platform coverage does not make it a fit for projects whose database layer is written in another language.

Who it's for

SQLDelight is a strong candidate for Kotlin developers building database-backed applications who want SQL checked at compile time and migration verification in a Gradle workflow. Teams using SQLite, MySQL, or PostgreSQL have the clearest dialect fit. Those considering experimental HSQL/H2 or third-party CockroachDB, DB2, or Oracle dialects should be more cautious. It is a poor choice for teams seeking language-agnostic code generation.

Pros and cons

Pro: Compile-time checks cover schemas, SQL statements, and migrations, helping catch database issues before runtime.
Pro: Flow, RxJava, and AndroidX Paging extensions provide options for Kotlin applications with reactive or paging needs.
Pro: The open-source library has no paid tiers, so using it does not require a subscription.
Con: Its generated APIs target Kotlin, excluding teams that need a generator for other languages.
Con: Experimental and third-party dialects are less straightforward choices than the documented SQLite, MySQL, and PostgreSQL dialects.

Alternatives

Code Generators and Mobile Databases are useful categories for comparing tools by broader needs. Among the specific alternatives, pick based on what you need generated:

quicktype is another free, open-source Apache-2.0 option, with a web app and CLI; consider it when that combination suits your code-generation task better than SQLDelight's Kotlin SQL focus.
Swagger Codegen is a free open-source option for generating API clients, server stubs, and documentation from OpenAPI specifications; choose it for OpenAPI work rather than SQL-to-Kotlin generation.
TypeSpec is a free, open-source, Microsoft-built, community-supported project with a CLI and online playground; consider it when that project format is a better match than SQLDelight's Kotlin database workflow.
Nx offers a free Hobby plan with 50,000 monthly-reset credits, five contributors, and 10 concurrent CI connections; it is a better fit when those build and CI limits suit your needs.
APIMatic has a free plan limited to HTTP plus any two programming languages, one API, 10 endpoints, and one team member; choose it when those API constraints fit better than SQLDelight's database focus.
Stainless has a free plan for up to five generators and five seats, with endpoint and preview-build limits; consider it when those generator and seat allowances fit your project.
Fern has a free plan with team, page, AI-credit, page-generation, and site limits; consider it when those allowances suit your use case.
Angular CLI is a free alternative with no paid plans or usage limits stated on its official pages; choose it when it better matches your project.

Verdict

Choose SQLDelight for a Kotlin application when you want SQL-derived APIs and compile-time checks for schemas, queries, and migrations without paying for a license. Look elsewhere if you need another target language, or if your required database depends on an experimental or third-party dialect that does not meet your project's needs.

	NSwag	SQLDelight
Free plan		Yes
Paid from		Free
Platforms	Linux, macOS, Windows	Android, api, iOS, Linux, macOS, Web, Windows
Free plan	Yes
Custom templates	Yes
Schema-to-code generation	Yes	Yes
CLI available	Yes
Supported languages	C#, TypeScript	Kotlin
IDE plugins		Yes

NSwag vs SQLDelight

NSwag

SQLDelight