API Mock Server Config Generator — Build Instant Mock Endpoints Online
Paste API route definitions to instantly generate JSON configuration files for json-server, Mockoon, and Prism mock servers. Define routes as METHOD /path lines and get ready-to-use config with realistic sample data.
How to Use API Mock Server Config Generator — Build Instant Mock Endpoints Online
How to Use the Mock Server Config Generator:
Load an Example or Paste Routes: Click a preset (Blog API, E-commerce, Auth API, Minimal CRUD) to populate the input, or paste your own routes directly into the textarea.
Route Format: Each line should follow the format: METHOD /path — for example: GET /users or POST /users/:id. You can optionally specify a status code: DELETE /users/:id 204. Lines starting with # are treated as comments and ignored.
Supported Methods: GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS. Paths can include named parameters using :param syntax (e.g. /users/:id).
Choose Output Format:
- json-server: Generates db.json with sample data collections. Run with: npx json-server db.json
- Mockoon: Generates an environment file you can import directly into the Mockoon desktop app via Open Environment.
- Prism (OpenAPI): Generates an OpenAPI 3.0 JSON spec with examples. Run with: npx @stoplight/prism-cli mock openapi.json
Click Generate Config: The tool parses your routes, fills in realistic sample data based on resource names (users, products, orders, posts, etc.), and produces the complete config JSON.
Copy or Download: Use the Copy button to copy the JSON to your clipboard, or click the filename button (db.json, mockoon.json, openapi.json) to download the file directly.
Switch Formats: Select a different output format with the radio buttons — the config regenerates instantly without re-clicking Generate.
Frequently Asked Questions
Most Viewed Tools
Screen Size Converter — Diagonal Dimension Tool
Calculate screen width and height from diagonal size and aspect ratio. Convert between inches and centimeters for displays, TVs, and monitors with instant dimension calculations.
Use Tool →DPI Calculator — Print Resolution Tool
Calculate DPI (dots per inch), image dimensions, and print sizes. Convert between pixels and physical dimensions for printing and displays.
Use Tool →TOTP Code Generator — 2FA Testing Tool
Generate time-based one-time passwords from a TOTP secret key. Enter your base32 secret, choose a period and digit length, and get the current and next codes with a live countdown timer. Useful for testing and debugging 2FA integrations.
Use Tool →JSONL Formatter — Line-by-Line Validator
Format, validate, and inspect JSON Lines (JSONL) and NDJSON files. Validates each line individually, reports parse errors by line number, outputs compact JSONL or a pretty-print preview, and lets you download the cleaned file.
Use Tool →JSON to Zod — Schema Generator
Generate Zod validation schema code from a JSON sample object. Infers z.string(), z.number(), z.boolean(), z.array(), z.object(), and z.null() types automatically. Handles nested objects, arrays of objects with optional field detection, and outputs copy-ready TypeScript with import and z.infer type alias.
Use Tool →Password Entropy Calculator — Crack Time Estimator
Calculate the information-theoretic bit entropy of any password or API key. Detects character set pools automatically, shows the total number of possible combinations, and estimates crack time across five attack scenarios from rate-limited web logins to GPU cracking clusters.
Use Tool →TLS Cipher Suite Checker — Strength Analyzer
Check TLS protocol version compatibility and cipher suite strength ratings against current best practices. Supports IANA and OpenSSL cipher names — rates each suite as Strong, Weak, or Deprecated and explains why.
Use Tool →Secret Scanner — API Key & Credential Detector
Scan pasted text, code, or config files for accidentally exposed API keys, tokens, passwords, and private keys. Detects 50+ secret types across AWS, GitHub, Stripe, OpenAI, and more — all client-side, nothing leaves your browser.
Use Tool →Related API & Backend Tools
HTTP Retry Policy Builder — Configure Resilient API Client Logic
Configure max retries, initial delay, backoff multiplier, jitter, max delay cap, and retryable HTTP status codes to instantly generate ready-to-use retry policy code for Axios (with axios-retry), native Fetch API (Node 18+ and node-fetch), and Go net/http. Supports presets for Standard, Aggressive, Conservative, and Rate-Limit Aware policies. All code is generated in your browser — free, instant, no signup.
Use Tool →GraphQL Subscription Builder — Generate WebSocket Payloads and Client Queries
Build GraphQL subscription query strings and generate WebSocket connection code snippets for Apollo Client, urql, and graphql-ws. Define your operation name, variables, and selection fields visually, then copy the ready-to-use code.
Use Tool →GraphQL Cost Estimator — Analyze Query Complexity and Depth
Assign custom field weights to a GraphQL schema and calculate the total query complexity score. Paste any GraphQL query, configure per-field costs, and get a per-field breakdown table showing depth, multipliers, and cumulative cost.
Use Tool →OpenAPI Spec Validator — Swagger Compliance Checker
Validate OpenAPI 2.0 (Swagger) and OpenAPI 3.0/3.1 specification files for compliance, missing required fields, unresolved $ref paths, and schema errors. Paste JSON or YAML or upload a file — errors and warnings are listed by path with severity levels and actionable fix suggestions. All validation runs entirely in your browser.
Use Tool →Postman to OpenAPI Converter — Spec Migration Tool
Convert Postman Collection v2.1 JSON to OpenAPI 3.0 specification format. Upload or paste your collection, and get a downloadable openapi.yaml or openapi.json with mapped paths, parameters, request bodies, and example responses.
Use Tool →REST Endpoint Documenter — Markdown Doc Generator
Document a REST endpoint quickly by entering the URL, method, headers, and sample request/response. Generates formatted Markdown documentation and an example cURL command instantly.
Use Tool →API Latency Budget Calculator — Plan Distributed System Performance
Set a P99 SLO latency target and distribute the budget across your upstream service dependencies. See remaining headroom, utilization percentage, a stacked allocation bar, and a per-service breakdown with optional P99 actual measurements.
Use Tool →API Tester — In-Browser REST Client
Test HTTP API endpoints directly in your browser. Make GET, POST, PUT, PATCH, and DELETE requests with custom headers and request bodies. View status codes, response headers, and pretty-printed JSON responses — all client-side, no server proxy.
Use Tool →Share Your Feedback
Help us improve this tool by sharing your experience