supaschema and Flyway sit at adjacent stages of the migration lifecycle. Flyway is a mature, multi-database migration runner: it applies versioned SQL scripts in order. supaschema is a Postgres-native generator, checker, and gated sync orchestrator: it renders replay-safe migration SQL from declarative SQL, proves it, and can apply it to configured PostgreSQL targets.
Short answer
Usesupaschema to generate and check a Postgres migration from declarative SQL for free, with no live database. Use Flyway to apply versioned migrations across many databases. They can work together: generate and check with supaschema, then apply with Flyway. Flyway’s own schema-diff auto-generation is a paid Enterprise feature; supaschema’s generation is free.
Comparison
| Capability | supaschema | Flyway |
|---|---|---|
| Primary role | Generate and check migrations | Apply versioned migrations (runner) |
| Migration source | Declarative SQL, diffed via parse trees | Versioned SQL scripts you author (or Java) |
| Auto-generate from a schema diff | Yes, free | Paid (Flyway Enterprise generate); Community is hand-authored |
| Live database needed to generate | No | Not applicable in Community; Enterprise generate compares schemas |
| Replay-safety and lock-hazard checks | Yes, free (supaschema check) | Paid (Enterprise code checks and drift detection) |
| Applies migrations | Yes, through explicit or approved automatic supaschema sync targets | Yes (flyway migrate) |
| Database support | Any PostgreSQL database (any provider) | Many database engines |
| Generated types | TypeScript and Zod from the SQL tree | None |
| Editions | Free core (open) | Community (free) and Enterprise (paid) |
Why choose supaschema for generation
- Generating a migration from a schema change is free and needs no live database; in Flyway, schema-diff auto-generation is an Enterprise (paid) capability and Community migrations are hand-authored.
supaschema checkgates replay-safety and lock hazards for free; Flyway’s equivalent code checks and drift detection are Enterprise features.- Output is PostgreSQL SQL plus generated TypeScript and Zod types.
When Flyway still fits
- Choose Flyway when one migration runner must manage many database engines.
- Choose Flyway when your deployment lifecycle depends on its history-table mechanics, undo scripts, or repeatable migrations.
- Use
supaschema syncwhen the target is PostgreSQL and you want the package-owned generation, safety, type-output, reconciliation, and apply lane.
supaschema diff and supaschema check to author and prove the SQL, then either supaschema sync for PostgreSQL targets or Flyway Community to apply the versioned script.
Flyway editions and feature gating are set by Redgate and can change. Last verified 2026-06-17 against Redgate Flyway documentation; confirm current terms before relying on them.
Liquibase comparison
How supaschema compares to Liquibase’s changelog-based migration runner.
The check command
The replay-safety and lock-hazard diagnostics supaschema runs for free.