Mockfly
Mockfly creates hosted mock REST API endpoints for teams that need to build and test before a backend is ready.
What Mockfly is
Mockfly creates hosted mock REST API endpoints for teams that need to build and test before a backend is ready. Endpoints can return JSON, XML, or files such as PDFs and CSVs, and can select among multiple responses using rules based on incoming requests. You can populate mock data with Faker.js templates or AI-generated JSON, and start from OpenAPI, Swagger, Postman, or HAR imports. A Chrome extension captures browser requests and adds selected endpoints to a project. Teams can share and edit mocks, review request logs, and view response-body history. For offline work, the mockfly-cli npm package pulls projects and serves them locally; a public REST API and MCP server support programmatic mock management. Mockfly is available through the web, API, Linux, an extension, and self-hosting. The free Starter plan allows 500 requests per day, one project, four endpoints, and two responses per endpoint.
Good
- Conditional rules select among multiple endpoint responses.
- Imports OpenAPI, Swagger, Postman, and HAR files.
- Faker.js templates and AI can generate mock data.
- CLI can serve projects locally without internet.
- Teams can share mocks and inspect request history.
Watch out
- Starter is limited to 500 requests per day.
- Starter allows one project and four endpoints.
- Starter allows two responses per endpoint.
- Team costs €49 a month.
Who it suits
Mockfly suits frontend, backend, mobile, QA, and testing engineers who need shared mock APIs. It is also useful for teams that want to import API definitions, automate mock management, or serve projects locally offline.
Verdict
Mockfly combines hosted mock endpoints, data generation, imports, collaboration, and local serving in one tool. The Starter limits are worth checking if a project needs more requests, endpoints, or response variations.
Plans and prices
From Mockfly's own pricing page, checked 15 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Starter | Free | 500 requests/day · 1 project · 4 endpoints · 2 responses per endpoint · 0€ per month |
| Pro | €15 a month | Unlimited requests · projects · endpoints · responses · AI JSON generation · AI endpoint descriptions · custom domain · callbacks · 15€ per month |
| Team | €49 a month | Everything in Pro · 5 seats · 9€ per extra seat · free-account collaborators · one invoice · priority support · 49€ per month for 5 seats |
| Pro annual | €150 a year | Same Pro features and limits · 150€ per year |
| Company | Priced on request | Everything in Team · OpenAPI/Postman setup · centralized billing · custom seats/integrations/SLA · direct builder contact · From 199€ per month |
The facts
Each one read from Mockfly's own pages, with the date it was checked.
What it does
- AI generation
- Natural-language descriptions can generate JSON response structures and endpoint descriptions.checked 15 Oct 2026
- API specification
- The public API has a machine-readable OpenAPI 3.1 specification and a Postman collection.checked 15 Oct 2026
- Automatic documentation
- Mockfly generates documentation from defined endpoints and keeps it available for sharing.checked 15 Oct 2026
- Automation
- A public REST API and an MCP server can be used to create and edit mocks programmatically.checked 29 Sep 2026
- Callbacks
- Paid plans can send delayed outgoing webhooks with retries, headers, bodies and optional HMAC-SHA256 signatures.checked 15 Oct 2026
- Chrome extension
- The extension captures browser requests and lets users add selected requests to a Mockfly project.checked 15 Oct 2026
- Conditional responses
- Rules select responses using request parameters, headers or body content.checked 15 Oct 2026
- Custom domains
- Paid plans can serve mocks on a customer hostname with Mockfly-managed TLS certificates.checked 15 Oct 2026
- Data formats
- Endpoints can return JSON, XML, or files such as PDF and CSV.checked 29 Sep 2026
- Data generation
- Mockfly supports Faker.js templates and AI-generated JSON payloads.checked 29 Sep 2026
- Data handling
- The company says it stores mock definitions and project request logs only to run the service, does not sell them and does not set tracking cookies.checked 15 Oct 2026
- Dynamic routes
- Path parameters such as /users/:id are supported.checked 15 Oct 2026
- Endpoint creation
- Users define paths, HTTP methods, status codes, headers and response bodies in a browser without installing software.checked 15 Oct 2026
- Extension privacy
- The Chrome listing says the developer does not collect or use user data and does not sell it.checked 15 Oct 2026
- Faker.js integration
- Faker.js placeholders generate changing realistic names, emails, addresses and other data on requests.checked 15 Oct 2026
- Imports
- OpenAPI, Swagger, Postman and HAR captures can be imported into editable projects.checked 15 Oct 2026
- Integrations
- The Chrome extension captures browser requests and adds selected endpoints to a Mockfly project.checked 29 Sep 2026
- Intended users
- Mockfly describes its users as frontend, backend, mobile, QA, and testing engineers who need shared mock APIs.checked 29 Sep 2026
- Limit: AI accuracy
- A G2 reviewer says AI responses are not always fully accurate and need adjustment.checked 15 Oct 2026
- Limit: manual synchronization
- G2 reviewers say changes in the real API must be copied into Mockfly manually.checked 15 Oct 2026
The company
- Company location
- The site footer identifies Madrid as Mockfly's location.checked 15 Oct 2026
- Company origin
- Mockfly says it was started in 2023 by Sergio Zamarro and is self-funded by a small independent developer team.checked 15 Oct 2026
- Founded
- 2023checked 28 Sep 2026
Where it runs
- Limit: desktop app
- A G2 reviewer notes that Mockfly has no desktop version.checked 15 Oct 2026
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