Both Mock Data Lab and Mockaroo solve the same everyday annoyance: you need realistic fake data to build or test against, and typing out fifty believable user records by hand is soul-destroying. But they get there from different directions. Mock Data Lab, one of Wigley Studios' free Developer Labs tools, generates data from a schema you already have — a JSON Schema, a TypeScript interface, or a sample response — entirely in your browser. Mockaroo is a long-established, hosted generator built around a deep library of realistic field types you assemble into a schema. Which one fits depends on how you think about your data and where you want it generated.
What Each Tool Does
Mock Data Lab takes a data shape and fills it in. You paste a JSON Schema, a TypeScript interface, or an example JSON response, and it produces matching records — 1 to 1,000 per run — that you export as JSON, CSV, or SQL INSERT statements. Its standout trick is reading your existing types: hand it a TypeScript User interface and it returns users with realistic numeric IDs, human names, valid emails, and properly shaped arrays, no translation step. Smart field detection means a field called email gets a real-looking address, price gets a plausible number, and createdAt gets an ISO timestamp. Crucially, it runs entirely in your browser — no account, nothing uploaded, free.
Mockaroo approaches it from the field side. You build a schema by adding columns and choosing from a very large library of realistic data types — names, addresses, geo coordinates, company names, and hundreds more — then generate and download data in a range of formats. As of June 2026 it is a hosted, server-side service with a free tier and paid plans, and it also offers hosted mock REST endpoints and an API for programmatic generation. (Mockaroo's exact limits and features change — verify on mockaroo.com.)
The Core Difference
Mock Data Lab is schema-first and local: it turns the types you already have into data, in your browser, for free. Mockaroo is field-library-first and hosted: you assemble a schema from a deep catalog of realistic types on their servers. One starts from your contract; the other starts from their data catalog.
Feature Comparison
| Feature | Mock Data Lab | Mockaroo |
|---|---|---|
| How you define data | JSON Schema, TypeScript interface, or sample JSON | Assemble fields from a type library |
| Where data is generated | Your browser (nothing uploaded) | Their servers (cloud) |
| Generate from existing types | Yes — paste a TS interface | Not the primary workflow |
| Realistic field-type breadth | Smart detection by field name | Very large, hand-picked catalog |
| Export formats | JSON, CSV, SQL INSERT | CSV, JSON, SQL, Excel, and more |
| Hosted mock REST API | No | Yes |
| Account required | No account | Account for most use |
| Price | Free | Free tier + paid plans |
| Best for | Generating data from a contract, fast and private | Exotic realistic domains + a hosted mock API |
When Mock Data Lab Is the Better Choice
- You already have the types. If your frontend has a TypeScript interface or your API has a JSON Schema, Mock Data Lab turns that contract straight into data — no rebuilding the schema field by field.
- You care about privacy. Everything runs locally in your browser. Nothing about your data shape leaves your machine, which matters when your schema itself is sensitive.
- You want zero friction. No account, no sign-up, no row counter ticking down. Open the tab, paste, generate, export.
- You're building the frontend before the backend. Schema-first teams can generate test data from an agreed contract immediately, while the API is still being built — the whole point of parallel frontend development.
When Mockaroo Is the Better Choice
- You need very specific realistic domains. Mockaroo's catalog of data types is broad and battle-tested — if you need believable street addresses, IBANs, or industry-specific values out of the box, the library is its strength.
- You want a hosted mock API. Beyond files, Mockaroo can serve mock REST endpoints, which Mock Data Lab does not do.
- You generate large volumes or automate it. Its paid tiers raise row limits and add API access for programmatic generation in CI or scripts.
- You prefer building schemas visually. If you think in columns and dropdowns rather than in JSON Schema or TypeScript, the field-picker workflow may feel more natural.
The Short Answer
Reach for Mock Data Lab when you already have a schema or TypeScript types and want fast, private, free data without an account. Reach for Mockaroo when you need its deep library of realistic field types, a hosted mock API, or high-volume generation through a paid plan.
Pricing Comparison
Mock Data Lab
- Free — no account required
- Runs entirely in your browser
- Up to 1,000 records per generation
- JSON, CSV, and SQL INSERT export
- Part of the free Developer Labs suite
Mockaroo
- Free tier with row and schema limits
- Paid plans for more rows and API access
- Hosted mock REST endpoints
- Broad realistic field-type library
- Server-side generation
Mockaroo's tiers, row limits, and features change — check mockaroo.com directly for current numbers. Mock Data Lab details reflect the Wigley Studios tool as of June 2026.
It Comes Down to Schema-First vs Field-First
This is less a price fight than a workflow choice. If you already have a contract — a JSON Schema or TypeScript types — generating from it locally and for free is hard to beat, and the data matches your code exactly. If you have no schema yet and want to assemble one from a rich menu of realistic types, or you need a hosted mock API, that is squarely Mockaroo's territory. Decide which describes your situation and the tool follows.
Can You Use Both?
Easily. Plenty of developers prototype quickly with Mock Data Lab when they already have types in hand, then turn to Mockaroo for a one-off dataset that needs an exotic field type or a hosted endpoint to point a demo at. They are not mutually exclusive — they just shine at different moments. For a related developer-tooling matchup, see our comparison of API Contract Lab vs Postman.
The Bottom Line
Mockaroo is the better tool when you want a deep, ready-made library of realistic data types, a hosted mock API, or high-volume generation, and you are comfortable working on a hosted service with a paid plan above the free tier. Mock Data Lab is the better tool when you already have a schema or TypeScript types and want to turn them into believable data instantly — free, in your browser, with nothing uploaded and no account in the way.
Start from how you arrive at the data: do you have a contract already, or are you building the shape from scratch? Answer that, and the right generator picks itself.
Generate Test Data in Seconds — Free
Mock Data Lab turns a JSON Schema, TypeScript interface, or sample JSON into realistic records, right in your browser. No account, nothing uploaded.
Open Mock Data Lab