Free hosted mock API server — no install required

Create Fake REST APIs Instantly — No Backend Needed

Spin up live HTTPS mock endpoints in seconds. Set any status code, latency, or response body — no backend, no installs, no waiting.

No credit card. No setup. Works in under 60 seconds.

Live HTTPS endpoint
terminal
ready
No install · hosted mock
10k+
Mock requests served
<60s
From sign-up to first mock
100%
No server code needed
v2.1
Postman collection support
The Problem

Backend not ready?
You shouldn't be blocked.

Frontend and mobile teams waste days waiting for APIs that aren't ready. Every existing mock API solution is either too complex to set up or too limited to be useful.

Waiting on the backend team

Feature development stalls because the mock API endpoints you need aren't ready yet. Sprint velocity tanks while you wait for a backend that may ship weeks later.

🔧

Local mock servers are fragile

json-server, hardcoded JSON files, and if-statements in your fetch logic are messy. They only work on your machine, break on merge, and can't simulate real network latency or errors.

💸

Enterprise API mocking tools are overkill

WireMock requires a JVM. Mockoon requires a desktop install. Postman mock servers are buried behind a paid plan. All of this for a fake REST API that should take 60 seconds to create.

The mock API server for
every developer who can't wait

MockJet is used by frontend developers, QA engineers, mobile teams, and full-stack teams who need a fake REST API running now — not after the backend ships.

🖥️

Frontend developers

Build React, Vue, or Angular components against a real live HTTPS endpoint before the backend exists. No more hardcoded JSON or conditional fetch logic — swap the mock URL for the real one when it's ready.

🧪

QA & test engineers

Simulate every edge case your real API won't reliably produce — 429s, 503s, slow responses, empty arrays, malformed JSON — on demand, every time, without touching a staging environment.

📱

Mobile developers

Develop iOS and Android apps against stable mock API endpoints. Share URLs across the team without running a local server or opening ngrok tunnels. Works from any device on any network.

🔁

CI/CD pipelines

Point integration tests at a MockJet endpoint to decouple your pipeline from flaky third-party APIs or unstable staging environments. Consistent responses, zero setup, always available.

🎨

Designers & prototypers

Wire real data into Figma prototypes, demos, and client presentations. Create a fake API endpoint in under a minute and show stakeholders a working product — no engineer required.

🤝

Full-stack teams

Agree on an API contract upfront, publish it as a mock server, and let frontend and backend build in parallel. No more blocked sprints, no more "waiting for the backend" stories in your backlog.

Four steps to a working mock

No CLI, no config files, no Docker. Just your browser.

1

Create a project

Sign in with Google and create a project. You get a unique base URL instantly.

2

Add endpoints

Choose the HTTP method, path, and set up one or more response variants.

3

Configure responses

Set status codes, headers, body JSON, delays, and simulate timeouts.

4

Hit the URL

Point your app at the mock URL. Watch live request logs stream in real-time.

Everything a mock API server
should do, nothing it shouldn't

MockJet packs every feature a real mock API server needs — response modes, latency simulation, live logs, Postman import — with zero configuration overhead.

Instant mock API endpoints

Create fake REST API endpoints in seconds — any HTTP method, path, status code, and JSON body. Your live HTTPS mock URL is ready the moment you save.

🔄

Response modes

Static always returns the same response. Sequential rotates through a list. Random picks one unpredictably — simulate real-world variance.

Latency & timeout simulation

Add a custom delay in milliseconds to any mock response. Enable timeout mode to return a 504 and test how your app handles slow or failing APIs — no real slow API needed.

📋

Request logs

See every incoming request in real-time. Method, headers, body, IP, and which response was returned. Debug without guessing.

📦

Postman import & export

Import an existing Postman Collection v2.1 to scaffold your project in one click. Export back to Postman anytime.

👥

Team collaboration

Invite teammates as editors or viewers. Share projects without sharing credentials. Role-based access control built in.

🌐

Custom headers

Set any response headers per response — Content-Type, Authorization, CORS headers, rate-limit headers, anything your client expects.

📎

curl command export

Copy a ready-to-run curl command for any endpoint, including request body example and correct headers. Perfect for sharing with teammates.

🔗

Path parameters

Define routes with named parameters like /users/:id. MockJet matches them all and routes to the right mock.

🎯

Conditional response routing

Return different responses based on what's in the request. Match on body fields, headers, or query params using rules like body.role eq admin or header.Authorization not_exists. Test auth flows, validation errors, and edge cases — no backend code needed.

Dynamic response templating

Every response body can contain live template variables that resolve fresh on each request — {{uuid}}, {{randomEmail}}, {{randomInt(1,999)}}, {{timestamp}}, and more. Realistic random data, zero effort.

Webhook inspector

Get a unique HTTPS URL, send any HTTP request to it, and watch it arrive instantly. Full headers, body, IP, and geo-location streamed live. History persists in your browser — never lose a request. Configure the exact response the URL returns to the sender. A free webhook.site and RequestBin alternative.

Your mock, your way

Point any HTTP client at your MockJet URL. Here's what that looks like.

curl
JavaScript (fetch)
Python (requests)
Response
# Hit your mock endpoint directly from the terminal curl -X POST "https://mockjet.io/mock/my-project/api/orders" \ -H "Content-Type: application/json" \ -d '{"item": "Widget", "qty": 2, "customer_id": "cust_abc"}'
// Swap this URL for your real API endpoint when it's ready const response = await fetch("https://mockjet.io/mock/my-project/api/orders", { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ item: "Widget", qty: 2 }), }); const data = await response.json(); console.log(data); // {"id": "ord_123", "status": "created"}
import requests response = requests.post( "https://mockjet.io/mock/my-project/api/orders", json={"item": "Widget", "qty": 2, "customer_id": "cust_abc"}, ) print(response.status_code) # 201 print(response.json()) # {"id": "ord_123", "status": "created"}
HTTP/1.1 201 Created Content-Type: application/json X-MockJet-Endpoint: POST /api/orders X-MockJet-Response: Order Created (sequential, 1/3) X-MockJet-Delay: 120ms { "id": "ord_123", "status": "created", "item": "Widget", "qty": 2, "created_at": "2026-04-26T10:00:00Z" }

What's included

Everything you need to build and test mock APIs. Free, no card required.

  • 10 Projects
  • 10 Endpoints per project
  • 10 Responses per endpoint
  • 1 day log retention
  • 10 Team members

Common questions

No. MockJet runs entirely in your browser. Sign in with Google, create a project, and you get a live URL immediately — no npm, no Docker, no config files.
Yes. Import any Postman Collection v2.1 file and MockJet will scaffold all your endpoints automatically, including nested folders and saved example responses. You can also export back to Postman anytime.
Sequential mode cycles through your response list in order. The first request gets response 1, the second gets response 2, and so on. When it reaches the end, it loops back. This is useful for testing pagination, state transitions, or retry logic.
Yes. Invite teammates by email and assign them a role: Editor (can create and modify endpoints) or Viewer (read-only access). Owners have full control including deleting the project.
MockJet is designed for development and testing — mocking dependencies during frontend development, integration testing, demos, and CI environments. It's not intended as a replacement for a production API server.
MockJet is a free online mock API server — a tool that lets you create fake REST API endpoints with configurable HTTP responses, status codes, latency, and headers. You use it to simulate a real backend API during development or testing, without writing any server code. Your mock endpoints are live HTTPS URLs accessible from anywhere the moment you create them.
Mockoon is a desktop application — it runs a local mock server on your machine, so your fake API endpoints are only accessible at localhost. MockJet is fully cloud-hosted: your mock endpoints are live public HTTPS URLs accessible from any device, teammate, or CI pipeline with no download, no local server, and no ngrok tunnel required. MockJet also adds team collaboration with role-based access and Postman Collection import on a free tier.
Yes. Like Beeceptor, MockJet gives you a hosted HTTPS mock endpoint with real-time request logs. MockJet additionally offers sequential and random response modes (rotate through a list of responses per endpoint), per-response latency simulation, Postman Collection v2.1 import and export, and full team collaboration with owner/editor/viewer roles — all available on the free plan.
Sign in to MockJet with Google (free, no credit card), create a project, and add your first endpoint — choose the HTTP method, set the URL path, configure the JSON response body and status code, and your live HTTPS mock API URL is ready in under 60 seconds. No npm, no Docker, no config files. You can also import an existing Postman Collection to scaffold an entire project in one click.
Yes, and it removes all the setup. json-server requires Node.js, a local npm install, and only exposes a localhost URL — which means your mobile device, a teammate's machine, or a CI pipeline can't reach it without extra tooling like ngrok. MockJet is fully hosted, so your mock REST API endpoint is a public HTTPS URL from the start. It also adds sequential/random response modes, latency simulation, and team sharing that json-server doesn't support.

Yes — this is called conditional response routing. You attach match rules to any response. A rule has three parts: where to look (body, header, or query), what field to check, and which operator to use.

Available operators: eq, neq, contains, not_contains, regex, exists, not_exists.

Examples:

  • Return HTTP 401 when header.Authorization not_exists
  • Return admin data when body.role eq admin
  • Return HTTP 422 when body.email not_exists
  • Return an empty list when query.filter eq none

Rules are evaluated in sort order — the first response whose rules all pass is returned. Responses with no rules are catch-alls, handled by the endpoint's fixed/random/sequential mode. No code, no backend.

MockJet supports dynamic response templating. Place {{variable}} tokens anywhere in your response body — they resolve to fresh values on every request.

Available tokens:

  • {{uuid}} — UUID v4
  • {{timestamp}} — ISO 8601 UTC timestamp
  • {{timestamp_ms}} — Unix milliseconds
  • {{randomBool}} — true or false
  • {{randomInt(1,1000)}} — integer in range
  • {{randomFloat(0.5,99.9,2)}} — decimal with precision
  • {{randomName}} — full name
  • {{randomEmail}} — email address
  • {{randomPhone}} — phone number
  • {{randomItem(pending,processing,complete)}} — pick from list

Example: {"id":"{{uuid}}","name":"{{randomName}}","created":"{{timestamp}}"} returns unique realistic data on every hit.

MockJet gives you two approaches:

1. Conditional routing — add a rule to any response so the error only fires when the request matches. For example: return HTTP 401 when header.Authorization not_exists, return HTTP 429 when body.qty regex ^[5-9]\d{2,}, or return HTTP 500 for a specific endpoint path. This lets you test your error-handling UI against a real HTTPS endpoint with no backend.

2. Static error response — just create a response with status code 400, 401, 403, 404, 422, 429, 500, 502, or 503 and set it as the active response. Switch between happy-path and error-path with one click in the dashboard.

You can also enable timeout mode to make the endpoint hang for a configurable delay and then return a 504 Gateway Timeout — useful for testing loading states and request cancellation.

Yes. Using conditional response routing, you can make a single endpoint behave exactly like an auth-aware API. A common setup looks like this:

  • Response 1 — 401 Unauthorized: rule header.Authorization not_exists
  • Response 2 — 403 Forbidden: rule body.role eq viewer
  • Response 3 — 200 Admin data: rule body.role eq admin
  • Response 4 — 200 Default: no rules (catch-all)

MockJet evaluates rules in sort order — the first match wins. Your frontend team can test the full auth flow — missing token, insufficient permissions, valid admin token — against a live HTTPS URL from day one. No backend, no token issuance, no staging environment.

Yes. MockJet includes a built-in webhook inspector. You get a unique HTTPS URL that accepts any HTTP request from any sender. Open the inspector page and incoming requests stream in real-time — showing the full method, path, headers, body, sender IP address, and geo-location (country, city, ISP).

Request history is persisted in your browser's localStorage so you never lose it on page reload. You can:

  • Copy any incoming request as a curl command
  • Add notes to individual requests
  • Filter by method, IP, path, or body content
  • Configure the response the URL returns to the caller (status code, JSON body, delay)

No install, no linking required — just create a webhook, copy the URL, and start sending requests.

Yes. Like webhook.site and RequestBin, MockJet gives you a unique HTTPS URL that captures any incoming HTTP webhook request and displays full headers, body, method, and sender IP in real-time.

MockJet adds on top:

  • Live SSE streaming — requests appear instantly, no polling or page reload
  • localStorage history — survives navigation; requests buffered in DB while your browser is closed
  • Multi-tab sync — all open tabs update simultaneously via BroadcastChannel
  • Geo-IP lookup — country, city, and ISP for every request
  • Configurable response — set the status code, JSON body, and delay returned to the sender

All features are available on the free plan with no install required.

Stop waiting. Start building.

Your mock is 60 seconds away. No credit card, no setup, no drama.