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 →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 →Seconds to Time Converter — HH:MM:SS Formatter
Convert seconds to HH:MM:SS time format instantly with precise calculations and easy-to-read formatting.
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 →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 →Related API & Backend Tools
API Pagination Calculator — Offset & Cursor Tool
Calculate offset, limit, cursor, and page-based pagination parameters for API responses. Generates Link headers and standard response headers instantly.
Use Tool →CORS Header Generator — Cross-Origin Config Tool
Build CORS configuration headers interactively for web servers and APIs. Set allowed origins, methods, request headers, credentials, and preflight cache duration — then copy the generated Access-Control headers or ready-to-paste code snippets for nginx, Express.js, Flask, and .NET.
Use Tool →GraphQL Variables Formatter — Query Validator
Format and validate GraphQL query variables JSON for use in queries and API clients. Paste your variables JSON alongside a GraphQL query to instantly format the JSON, validate that each variable matches its declared type, catch missing required variables, and highlight undeclared extras.
Use Tool →API Changelog Generator — Automatically Detect Breaking Changes and Write Release Notes
Convert API change descriptions into structured Keep-a-Changelog format. Enter a version, date, and one change per line prefixed with its type (added, changed, deprecated, removed, fixed, or security). The tool instantly groups them into the canonical section order and outputs a ready-to-paste CHANGELOG.md block. Supports four real-world presets for REST API releases, breaking changes, patch releases, and unreleased work. Free and 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 →OAuth Token Validator — JWT & OIDC Decoder
Validate and inspect OAuth tokens in your browser. Decode JWT access tokens and ID tokens to view claims, scopes, and expiry. Analyse opaque tokens for entropy and format. Free and private.
Use Tool →JWT Token Validator — Signature Verifier
Decode and validate JWT tokens instantly in your browser. Inspect header and payload claims, check expiry, and verify HMAC signatures (HS256/HS384/HS512). Free and private.
Use Tool →Server-Sent Events (SSE) Formatter — Build and Debug Real-Time Streams
Build Server-Sent Events messages with id, event, data, retry, and comment fields for testing SSE endpoints. Fill in each field individually and instantly see the correctly formatted SSE message string with double-newline terminator. Supports multi-line data fields, keep-alive comment lines, and an escaped wire-format view. Five presets cover the most common SSE patterns. Free and runs entirely in your browser.
Use Tool →Share Your Feedback
Help us improve this tool by sharing your experience