Mokup - Mock APIs in DevTools

Capture requests in DevTools and mock API responses while building UI.

Mokup is a Chrome DevTools extension for frontend developers and QA/QC testers who need to inspect API traffic and quickly create local mock responses. Stop waiting for backend changes, broken DEV/QA APIs, slow deployments, or hard-to-reproduce edge cases. With Mokup, you can capture a real Fetch/XHR request and turn it into an editable mock response directly inside DevTools. Open DevTools, choose the Mokup panel, capture Fetch/XHR requests in the Live tab, then turn any request into a mock rule. Mock rules are stored locally in your browser and can be enabled, disabled, duplicated, edited, or deleted from the Mock tab. Key features: - Capture live Fetch/XHR requests in DevTools - View method, URL, status, type, source, and timing - Create mock rules from captured requests - Edit mock response body, status code, URL matcher, method, and delay - Toggle global mocking on or off - Enable or disable individual mock rules - Filter requests by method, type, source, and search text - See whether a request came from the real network or from a mock Use Mokup when: - Frontend work is blocked by backend endpoints that are not ready yet - Developers have not fixed an API issue yet, but QA/QC needs to keep testing - Test data in DEV/QA environments is missing, slow, or unstable - You need to unblock a test flow without waiting for backend changes - You need to test empty states, error states, loading states, or edge cases - You want to demo UI changes without changing backend code Privacy: Mokup stores mock rules locally in Chrome storage. It does not send captured requests, response bodies, or mock rules to any external server. Mokup injects into the inspected tab only when the DevTools panel is opened. Mokup is intended for frontend development, QA/QC testing, UI testing, API debugging, and local mock workflows.