Test data tools comparison: how to pick a test data generator
Our take: pick by workflow, not by a single “best.” We think Seedfast fits Postgres teams that want one CLI or MCP command that reads the live schema and seeds realistic relational data in CI, on flat pricing. Choose Tonic Fabricate if you need databases beyond Postgres, and Mockaroo if you want quick rows in a browser with no install. Snaplet and Neosync are no longer maintained.
Test data generators compared at a glance
Every cell below is sourced from our individual comparison pages, where each figure is dated and linked to the vendor’s own documentation. All pricing and capabilities shown here are current as of June 2026. The marks read ✓ yes, ✗ no, and ~ partial.
| Capability | Seedfast | Tonic Fabricate | Mockaroo | GenRocket | Snaplet (discontinued) | Neosync (archived) |
|---|---|---|---|---|---|---|
| Reads live Postgres schema every run | Yes. Reads your live schema on every run | Yes. Live Connect to read a real schema | No. Define columns by hand in a web form | Partial. Configured per project/domain | Yes. Codegen step reads schema (sunset) | Yes. Reads tables, columns, FK graph (archived) |
| FK / circular-FK handling | Yes. Schema-aware: topological order, resolves FK cycles | Yes. Relational, schema-aware generation | No. Manual — own web schema, not your DB | Yes. Enterprise relational generation | Yes. FK resolution in generated client | Yes. Topological FK resolution |
| Runs as a CLI / CI step | Yes. One command takes a connection string | Partial. CLI loads pre-generated data, not a seed step | No. Export, then import yourself | Partial. Via platform + integrations | Yes. tsx seed.ts ran in pipelines (sunset) | Partial. Temporal workflows, API-driven (archived) |
| MCP-native (AI coding agents) | Yes. Native MCP server (Claude Code, Cursor, any MCP client) | No. No MCP advertised | No. No MCP | No. No MCP | No. No MCP | No. No MCP |
| Pricing model | Yes. Flat — free tier + flat paid, no metering | Partial. Free ($10/mo credits); Plus $29/mo + ~$0.17–0.37/turn | Partial. Free 1k rows/file; $60–$7,500/yr tiers | No. Quote-gated; ~$55k/yr anchor, no list price | No. Hosted service shut down | No. Hosted service offline |
| Database scopeWhere a competitor wins | Partial. Postgres only (Supabase, Neon, RDS, plain PG) | Yes. Postgres, MySQL, Oracle, Databricks + exports | Partial. Export to many formats, column-level only | Yes. Many databases, enterprise breadth | Partial. Postgres-first (experimental MySQL/SQLite) | Yes. Postgres + MySQL |
The highlighted row is an honest concession: Seedfast is Postgres-only by design, so Tonic Fabricate and GenRocket cover more databases than Seedfast does.
Which test data tool should you choose?
Seedfast is the pick when you want one CLI or MCP command that connects to a live PostgreSQL database, reads the schema on every run, and seeds realistic relational data inside a CI pipeline — on flat pricing with no per-row or per-token metering. Watch the one-command demo, or read the best Postgres test data generator guide.
Seedfast is Postgres-first by design, so a different tool may fit better when:
- Tonic Fabricate fits if you need to generate into databases beyond Postgres — MySQL, Oracle, Databricks — or export to formats like Parquet and Avro, and a web/chat agent suits your team better than a CLI. See Seedfast vs Tonic Fabricate.
- Mockaroo fits if you want a flat CSV or a hosted mock API of plausible rows right now, with no install — its web UI is the fastest path to a first result. See the Mockaroo alternative comparison and Tonic Fabricate vs Mockaroo.
- GenRocket fits if you are an enterprise with a dedicated test-data team and a budget for a quote-gated platform (no public list price, ~$55k/year anchor as of June 2026). See the GenRocket alternative comparison.
- Migrating off a discontinued tool? Snaplet shut down on August 31, 2024 and Neosync was archived on August 30, 2025 — neither is an option for new projects. See the Snaplet and Neosync migration notes.
Which tool fits your use case?
Seeding a Postgres database
A real Postgres target — Supabase, Neon, RDS — needs a tool that reads the live schema and resolves foreign keys, including circular foreign keys, not a column-level generator you export by hand. See the Postgres generator guide.
CI/CD pipelines
An automated pipeline wants a single command after migrations, not a web UI you export from. See CI/CD database seeding and tools for regulated teams.
Fintech and compliance
When production data can’t go to dev, generating from a schema skips the PII pipeline. See test data for fintech and why generated beats masked.
Frequently asked questions
What is the best test data tool for a Postgres team?
It depends on the workflow you need. We think Seedfast fits teams that want a CLI or MCP command that connects to a live PostgreSQL database, reads the schema on every run, and seeds realistic relational data inside CI — on flat pricing with no per-row or per-token metering. Tonic Fabricate fits teams that need more than Postgres. Mockaroo fits a quick flat CSV with no install. The pick is about your surface (CLI vs web vs enterprise platform) and pricing model, not a single 'best' label.
How is Seedfast different from Tonic Fabricate?
Both are schema-aware generators that produce relational data from scratch without touching production, and both can connect to a live database to read a real schema, so neither 'reads the live schema' nor 'generates safe data' is a Seedfast-only edge. The differences are workflow and pricing: Seedfast is CLI-first and MCP-native and runs as one command in CI, while Fabricate is a web/chat agent with an SDK and API and no advertised MCP. Seedfast pricing is flat; Fabricate has a free tier ($10/month in credits) and a Plus plan at $29/month plus pay-as-you-go per turn (roughly $0.17 standard, $0.37 complex) beyond included credits (tonic.ai/pricing, as of June 2026). Fabricate covers more databases than Seedfast does.
When should I use Mockaroo instead of Seedfast?
Choose Mockaroo when you want a flat file of plausible rows right now with no install. Mockaroo's instant web UI is faster to a first result than any CLI tool, including Seedfast — opening a browser tab beats installing anything when you just need 500 rows of users in a CSV. Mockaroo's free tier allows 1,000 rows per file and 200 API requests per day, with paid tiers from $60/year (mockaroo.com/pricing, as of Jun 2026). It does not connect to your live database or resolve cross-table foreign keys in your schema, so for relational seeding into a real Postgres database a CLI tool fits better.
Are Snaplet and Neosync still maintained?
No. Snaplet shut down on August 31, 2024; the last meaningful @snaplet/seed release (v0.98.0) landed July 30, 2024, and a community fork has seen limited activity since. Neosync was acquired by Grow Therapy in September 2025, its GitHub repo was archived on August 30, 2025, and the hosted cloud service is offline. We list both for teams evaluating a migration off them, but neither is a current option for new projects (as of Jun 2026).
Which tools handle circular foreign keys?
Seedfast resolves foreign keys in topological order and handles circular foreign keys — the case an export-then-import workflow forces you to untangle by hand. Tonic Fabricate, GenRocket, and (while maintained) Snaplet Seed and Neosync also generate relationally. Mockaroo references only the datasets you define inside its own web form, not the foreign keys in your live database, so cross-table relational integrity in your schema is manual.
Does any of these tools require production data?
No — all of these tools generate or define data from scratch rather than copying production rows, so this is a shared category trait, not a differentiator of any one tool. If your constraint is regulatory (fintech, healthcare) the relevant question is the workflow and the data realism, not whether the tool avoids production data.
All comparisons
- Seedfast vs Tonic Fabricate — Same schema-aware category — CLI/MCP in CI and flat pricing vs a web agent with per-turn metering.
- Mockaroo alternative — Live-database relational seeding vs flat, column-level CSV exports.
- GenRocket alternative — Self-serve flat pricing vs an enterprise, quote-gated TDM platform.
- drizzle-seed alternative — Any-Postgres, semantic data and cycle handling vs a free Drizzle-only library.
- Tonic Fabricate vs Mockaroo — A schema-aware AI agent vs a flat column generator — with Seedfast as a third option.
- Snaplet Seed alternative — Where to move after Snaplet shut down in August 2024.
- Neosync alternative — A migration path after Neosync was archived in August 2025.
Try Seedfast on your own Postgres database
Point Seedfast at a connection string, describe the scenario you need, and watch it read the schema and seed realistic relational data in one command. The free tier covers small development datasets — no production data required.
Seedfast is not affiliated with, endorsed by, or sponsored by the products compared here. All product names, logos, and brands are the property of their respective owners and are used for identification purposes only. Comparisons reflect publicly available information as of the date shown.
Tonic Fabricate, Mockaroo, GenRocket, Snaplet, Neosync are trademarks of their respective owners.