API Response Mocker

Simulate API payloads for UI development with preset statuses, custom JSON bodies, and artificial latency. Build local mock HTTP JSON responses with status code

Introduction

API Response Mocker is a free, browser-based utility in our HTTP & API Tools collection. Simulate API payloads for UI development with preset statuses, custom JSON bodies, and artificial latency. Build mock API responses so frontends can prototype against predictable JSON without waiting on a backend. Everything runs locally in your browser — inputs stay on your device, with no account or upload required. Highlights include status presets.

Features

Status presets
Delay
JSON body editor

How to use

1
Pick a status and edit JSON.
2
Simulate and copy the mock.

Example

404

Input

status 404 + error JSON

Output

mock response object

Benefits

Run API Mocker entirely in the browser with no signup or installation.
Keep sensitive sample data private — processing never leaves your device.
Status presets
Delay
JSON body editor
Pair it with API Viewer and HTTP Status when your workflow needs adjacent utilities.

FAQs

No - this mocks objects locally only.

Not applicable; nothing is served over HTTP.

No.

Yes. API Mocker on EverydayDevTools is free, with no account, watermarks, or usage caps for normal interactive use.

No. API Mocker runs in your browser. Your input is processed locally and is not sent to EverydayDevTools servers.

Simulate API payloads for UI development with preset statuses, custom JSON bodies, and artificial latency. It fits everyday http & api tools tasks when you want a fast local utility instead of installing a CLI or opening a heavy IDE feature.

Core capabilities include: Status presets; Delay; JSON body editor.

Developers often pair API Mocker with API Viewer, HTTP Status, Fake Data. Open Related tools on this page for quick links.