Free · private · developer-friendly

Fake JSON Data Generator

Design a schema and generate realistic mock API responses in seconds. Use a preset or make your own, then copy clean JSON straight into your app.

Realistic presets Runs locally Seeded output
01 · Shape your data

Build a schema

Start with a preset
Fields0 fields
GET/api/users
200 OK12 ms
02 · Your response

Mock API response

8 records0 B

              
            

            

              
              
              
            

            
Private by design. Your schema and data never leave this browser.

          

        

      

    


    

      

        

          Prototype without waiting
          
Create realistic fake JSON data online

          
This online mock JSON generator gives frontend developers, QA engineers and product teams useful API data before a real endpoint exists. Define each field, select a response shape and generate consistent sample records for UI states, demos, tests and documentation.

        

        

          
01
Choose a useful schema
Start with users, products, orders or posts, then add, rename and remove fields to match your API contract.

          
02
Match your API shape
Return a plain array, a data wrapper, a single object or pagination metadata for realistic integration work.

          
03
Reproduce test data
Reuse a seed to get the same values again. Change it when you want a fresh response for another scenario.

        

        

          
Built for real workflows
From blank screen to believable prototype
Mock data is most valuable when it covers the same shapes and edge cases your production API will return.

          
    
            
  • </>
    Frontend development
    Build tables, cards, profiles and empty states while backend work continues.
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  • QA
    Testing and demos
    Create repeatable fixture data for reviews, screenshots and manual test cases.
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  • API
    API documentation
    Provide readable example responses that make endpoint behavior easy to understand.
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Fake JSON generator FAQs

          
What is a fake JSON data generator?
It creates realistic sample values that follow your chosen field names and data types. The output can stand in for an API response while you build a frontend, test a flow or document an endpoint.

          
Can I generate a paginated mock API response?
Yes. Select Paginated API to wrap your records in a data array with page, perPage, total and totalPages metadata.

          
How do I generate the same JSON again?
Keep the same seed, schema, count and response shape. The generator uses the seed to create repeatable values, which is useful for fixtures and demos.

          
Is my generated data stored or uploaded?
No. The fake data is generated locally in your browser. Nothing is uploaded by this tool, and refreshing the page starts from the default schema.

          
Is this mock JSON generator online free to use?
Yes. It is free to use online with no account, sign-up or software installation.

        

      

    


    

      

        

          
Keep building
Try other developer tools
Validate, transform and turn your generated response into working code.

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          JSON FormatterBeautify, validate, sort or minify JSON.
          JSON to CodeGenerate type-safe models from your response.
          JSON to CSVConvert records into spreadsheet-ready data.