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Mockfly
What it is
Mockfly creates hosted mock REST API endpoints for teams building and testing before a backend is ready. An endpoint can return JSON, XML, or files such as PDF and CSV, and can choose from multiple responses using rules based on incoming requests. Mock data can be built with Faker.js templates or AI-generated JSON. Teams can start from OpenAPI, Swagger, Postman collection, or HAR imports; a Chrome extension can capture browser requests and add selected endpoints to a project. Team members can share and edit mocks, inspect request logs, and view response-body history. For offline work, the mockfly-cli npm package can pull projects and serve them locally without an internet connection. A public REST API and MCP server support programmatic mock creation and editing. The free Starter plan allows 500 requests per day, one project, four endpoints, and two responses per endpoint. Pro costs €15 a month; Team is €49 a month with five seats; Company starts at €199 a month. Mockfly is available through web, API, Linux, extension, and self-hosting, and is intended for frontend, backend, mobile, QA, and testing engineers.
For and against
For
- Supports JSON, XML, PDF, and CSV responses.
- Imports OpenAPI, Swagger, Postman, and HAR.
- CLI can serve projects locally offline.
- Teams can review request logs and response history.
- Pro includes unlimited requests, projects, and endpoints.
Against
- Starter is limited to 500 requests per day.
- Starter allows one project and four endpoints.
- Team includes five seats; extra seats cost 9€ monthly.
- Company starts at €199 a month.
The verdict
Mockfly offers several ways to build, share, and run API mocks, including offline serving. The Starter limits are specific, so teams with heavier use may need a paid plan.
Who it suits
Mockfly suits frontend, backend, mobile, QA, and testing engineers who need shared mock APIs. It may fit teams that need to import API definitions or serve mocks locally while offline.
Plans and prices
Starter
500 requests/day · 1 project · 4 endpoints · 2 responses per endpoint
Read 15 Oct 2026 · mockfly.dev
Pro
Unlimited requests · projects · endpoints · responses
Read 15 Oct 2026 · mockfly.dev
Team
Everything in Pro · 5 seats · 9€ per extra seat · free-account collaborators
Read 15 Oct 2026 · mockfly.dev
Pro annual
Same Pro features and limits
Read 15 Oct 2026 · mockfly.dev
Company
Everything in Team · OpenAPI/Postman setup · centralized billing · custom seats/integrations/SLA
Read 15 Oct 2026 · mockfly.dev
On the record
- AI generation
- Natural-language descriptions can generate JSON response structures and endpoint descriptions.mockfly.dev · read 15 Oct 2026
- API specification
- The public API has a machine-readable OpenAPI 3.1 specification and a Postman collection.mockfly.dev · read 15 Oct 2026
- Automatic documentation
- Mockfly generates documentation from defined endpoints and keeps it available for sharing.mockfly.dev · read 15 Oct 2026
- Automation
- A public REST API and an MCP server can be used to create and edit mocks programmatically.mockfly.dev · read 29 Sep 2026
- Callbacks
- Paid plans can send delayed outgoing webhooks with retries, headers, bodies and optional HMAC-SHA256 signatures.mockfly.dev · read 15 Oct 2026
- Chrome extension
- The extension captures browser requests and lets users add selected requests to a Mockfly project.chromewebstore.google.com · read 15 Oct 2026
- Company location
- The site footer identifies Madrid as Mockfly's location.mockfly.dev · read 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.mockfly.dev · read 15 Oct 2026
- Conditional responses
- Rules select responses using request parameters, headers or body content.mockfly.dev · read 15 Oct 2026
- Custom domains
- Paid plans can serve mocks on a customer hostname with Mockfly-managed TLS certificates.mockfly.dev · read 15 Oct 2026
- Data formats
- Endpoints can return JSON, XML, or files such as PDF and CSV.mockfly.dev · read 29 Sep 2026
- Data generation
- Mockfly supports Faker.js templates and AI-generated JSON payloads.mockfly.dev · read 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.mockfly.dev · read 15 Oct 2026
- Dynamic routes
- Path parameters such as /users/:id are supported.mockfly.dev · read 15 Oct 2026
- Endpoint creation
- Users define paths, HTTP methods, status codes, headers and response bodies in a browser without installing software.mockfly.dev · read 15 Oct 2026
- Extension privacy
- The Chrome listing says the developer does not collect or use user data and does not sell it.chromewebstore.google.com · read 15 Oct 2026
- Faker.js integration
- Faker.js placeholders generate changing realistic names, emails, addresses and other data on requests.mockfly.dev · read 15 Oct 2026
- Imports
- OpenAPI, Swagger, Postman and HAR captures can be imported into editable projects.mockfly.dev · read 15 Oct 2026
