Mock Data Generator
Random JSON · Template placeholders · Batch generation
Mock generator
Ready
ABOUT
About Mock Data Generator
Define JSON templates with placeholders and generate multiple random test records in one click.
Frontend shouldn't be blocked by backend progress. The Mock generator batch-produces structurally correct JSON from templates, so list pages, forms, and chart components can be developed and visually verified before real APIs are ready.
DEEP DIVE
Learn More About Mock Data Generator
Frontend development often stalls when backend APIs aren't ready. The Mock data generator uses JSON templates and placeholder syntax to batch-produce random but structurally correct test JSON. JSONSort Mock runs locally, supporting randomization rules for strings, numbers, booleans, array lengths, and more.
Placeholders can nest at any JSON level—define a template once, generate N records as an array, and use directly as Mock Server or component props data.
Placeholder syntax works inside JSON string values; the generator picks random strategies by field name semantics (name → person name, email → email format, etc.). Fixed fields without placeholders repeat in every record—ideal for status, type, and other enum constants.
FEATURES
Core capabilities
Template Placeholders
Use placeholder syntax in JSON templates to generate random values.
Batch Generation
Specify count to produce multiple Mock records as an array in one go.
Type Randomization
Random types: strings, integers, floats, booleans, UUID, dates, and more.
Structure Preservation
Generated data strictly follows the template-defined JSON structure.
Instant preview
Regenerate immediately when template or count changes.
Local Generation
Mock data never hits the server—safe for prototyping.
Batch Count
Generate N records at once to simulate paginated total data volume.
Structure Constraints
Output strictly matches template JSON Schema shape with no extra keys.
HOW TO USE
How to use
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1
Write or paste a JSON template
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2
Set generation count
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3
Copy Mock data array
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4
Use the sample data button to quickly understand input/output formats
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5
Copy results to clipboard, or chain with other JSONSort tools
WORKFLOW
Typical workflow
End-to-end workflow from import to export, helping teams standardize Mock Data Generator usage.
Define Template
Write a JSON object and replace string values with {{field}} placeholders.
Set Count
Specify record count and preview array output.
Fine-Tune Template
Adjust fields and placeholder types based on UI needs.
Export Fixtures
Copy to src/mocks/ or MSW handlers.
USE CASES
Use cases
Frontend developers
Generate Mock data for list and detail pages during UI development.
QA engineers
Build edge-case test data: empty arrays, long strings, special characters.
Product Demo
Fill demo environments with realistic fake data to avoid blank pages.
Backend developers
Batch-generate API doc sample data for Swagger descriptions.
UI Development
Fill Storybook stories with 20 list Mock records.
Stress Testing
Generate large JSON volumes to test frontend virtual scrolling and memory.
TIPS
Tips
- Use Code Generator on real API samples for structure first, then replace fields with placeholders for Mock templates.
- For list pages, generate 10–20 Mock records to cover pagination and scroll testing.
- Placeholder names hint at types, e.g. {{name}}, {{age}}, {{email}}.
- After generation, copy to the formatter to verify structure, then import to Mock Server.
- Chain with JSON Formatter: Mock output → format → copy to project fixtures directory.
- Avoid real user PII in Mock data, even for local development.
- Get templates from Code Generator first, then change values to {{placeholder}}.
- Use {{uuid}} for id fields to avoid list key conflicts.
- Edge testing: generate 0, 1, and 1000 records to verify UI separately.
- Prefix Mock data with fake_ to avoid confusion with real data.
LOCAL VS ONLINE
Local vs online tools
JSONSort stays purely frontend—this comparison shows why local tools fit dev data better.
TROUBLESHOOTING
Common pitfalls & fixes
Issues you may hit in practice and how to handle them—save time on trial and error.
Placeholders Not Replaced
Tip:Must be {{name}} inside string values; non-strings won't be replaced.
Wrong Type
Tip:For numeric fields with placeholders, write strings in the template and post-process, or use fixed numbers.
Inconsistent Array Structure
Tip:Template defines a single record structure; the generator wraps it as an array.
PII Compliance
Tip:Even with Mock data, don't use real names or phone numbers in templates.
FAQ
FAQ
What is the placeholder syntax?
Use {{fieldName}} inside string values; the generator replaces them with random values.
Can I fix a specific field?
Fields without placeholders keep their original values in every record.
Generation count limit?
Depends on browser memory; hundreds of records are usually fine.
Is the random seed fixed?
Re-randomizes on each page refresh; save generated results if you need a fixed seed.
Can nested arrays be mocked?
Yes. Use placeholder strings inside nested objects too.
Is data uploaded to a server?
No. All JSONSort tools run locally in your browser—your input is never sent to any backend.
Do I need to sign up or install anything?
No. Open the page and go—no account, no client download, PWA offline cache supported.
How large can files be?
Depends on browser memory; multi-MB data usually runs smoothly. Split very large files or use merge & clean first.