ejlegoceikdkkflbpfmkoickppacklml
Intercepts and mocks HTTP requests with custom responses based on user-defined rules for free. The ultimate HTTP request interception tool for developers and QAs. Mock API responses and test any frontend scenario. Stop letting API dependencies slow you down. Intercepta is a powerful and intuitive tool that gives frontend developers and QA testers full control over HTTP requests. Mock any API endpoint, simulate error conditions, and test every edge case without waiting for the backend to be ready. Whether you're building a new feature or running a demo, Intercepta allows you to define custom responses on the fly, accelerating your development cycle and helping you build more robust applications. ___ ## Why You Need Intercepta > Build Without Blockers: Are you waiting for a backend API to be deployed? With Intercepta, you can mock the expected response and continue building your UI without interruption. > Test Every Scenario: Effortlessly test how your application handles different data states. Simulate a 404 Not Found error, an empty array, or a server-side 500 error with a single click. > Deliver Perfect Demos: Ensure your product demos run smoothly every time by mocking consistent and predictable data, removing the risk of a failing live API. ____ ## Key Features > Mock Any Request: Intercept GET, POST, PUT, DELETE, and other requests using powerful wildcard matching for URLs (e.g., *://api.example.com/users/*). > Context-Aware Activation: Create rules that only activate on specific websites, like localhost, your staging environment, or any other domain you choose. > Full Control Over Responses: Define your own response body with any JSON, HTML, or Text. The extension automatically handles common CORS and CSP issues to ensure your mocks work seamlessly. > Powerful Dashboard: A clean, two-column dashboard lets you see all your rules at a glance while you create or edit a new one. > Instant Toggle Popup: A simple popup menu lists all your named rules, allowing you to instantly enable or disable them without ever leaving your current tab. ____ ## How to Use 📋 1. Open the Dashboard: Right-click the Intercepta icon in your toolbar and select "Options" to open the main dashboard. 2. Create a Rule: Fill out the form to define your mock. Give it a name, specify the URL to Mock, and provide the Response Body you want to return. 3. Activate and Test: Use the popup menu (by left-clicking the toolbar icon) to quickly toggle your rules on or off. Refresh your test page to see the mocked response in action! ____ ## Privacy & Security Your data is yours. All your mocking rules are stored locally on your machine using chrome.storage and are never transmitted to any external
tweak: mock and modify HTTP requests
Mock or modify your HTTP requests to test, develop and demo your web application tl;dr tweak allows you to mock and modify HTTP requests without leaving the browser You can intercept requests/API calls and 🪄 ﹥ Modify ⁃ Response data and headers ⁃ Status code ⁃ Request payload 💸 ⁃ Request headers 💸 ﹥ Delay individual requests/API calls ﹥ Export and import rules to organize and share your configs with your team ﹥ Search requests in the background to import them automatically Premium 💸 ﹥ Modify the response data by writing custom JavaScript ﹥ Organize your workspace with collections ﹥ Change rules in bulk using global custom variables ﹥ Create mock data with random generators ﹥ Use tweak’s breakpoints and logpoints to debug requests/API calls What you CAN’T do with tweak 🚫 ﹥ Replace documents such as HTML/CSS/Images Useful links 🔗 ﹥Getting started https://tweak-extension.com/docs/intro ﹥FAQs https://tweak-extension.com/faqs ﹥Changelog https://tweak-extension.com/changelog ﹥Support help@tweak-extension.com
HTTP Request Blocker
This extension blocks HTTP Request based on configurable URL patterns. The patterns must conform to this specification: https://developer.chrome.com/extensions/match_patterns.
Mock Express - Modify, Mock & Intercept HTTP Requests Locally
Intercept, mock, and modify API requests directly in your browser. No server needed. 100% local and secure. 👨💻 Built by a developer for real-world debugging and testing, Mock Express helps you simulate edge cases, validate UI behavior, and test APIs with complete control—right from your browser. Designed for developers and QA teams, it removes the need for backend changes or complex setups, making it easy to reproduce failures, test different scenarios, and keep development workflows stable and predictable. ✨ Request rules → Modify outgoing requests: headers, query parameters, URL segments, and body → Block API calls to simulate failures or remove unwanted traffic → Add delays to test latency and slow network conditions → Match requests using exact, wildcard, or regex URL patterns ✨ Response rules → Mock or modify responses with custom status codes, headers, and body → Use static JSON, saved resources, or JavaScript for dynamic responses → Skip the actual network call when mocking ✨ DevTools workflow → Inspect captured requests directly in the DevTools panel → Create request/response rules instantly from captured traffic ✅ Why Mock Express ⚡ No backend required — everything runs locally 🔒 Privacy-first — no data leaves your browser 🎯 Flexible matching — supports exact, wildcard, and regex rules 🔄 Instant control — toggle rules without losing configuration 🧪 Reliable testing — simulate errors, delays, and edge cases easily 🛠 Developer-friendly — fast setup, no complex configuration 👨💻 Who it's for → Frontend developers: test UI behavior across success, error, and edge cases → QA engineers: reproduce failures and network conditions reliably → Teams: maintain consistent test scenarios even when APIs are unstable 🔒 Privacy → Mock Express runs entirely in your browser. All rules and settings are stored locally using browser storage. No accounts, no tracking, and no external servers. → Custom scripts are user-defined and executed locally within the browser. No code is fetched or executed from external sources. 🧩 Compatibility → Works with modern frameworks (React, Angular, Vue, etc.) → Supports REST APIs over HTTP (GraphQL support coming soon)
Inssman: Open-Source: Modify HTTP Request
Inssman add custom rules to modify HTTP requests and responses. It is a free developer tool that which helps developers to organize their work more fast and easy. Inssman monitors the browser network for all tabs and if finds a request which matches one of the rule will accordingly modify. ✳️ What can Inssman do?✳️ 👉 Redirect Request: ➡️ Redirect any request like HTML/CSS/JS/JSON/...etc. 👉 Block Request: ➡️ Block all type of request like GET/POST/PUT/...etc 👉 Modify Query Params: ➡️ Easily remove presenting parameters in the url or replace the existing one or adding new parameter. 👉 Modify Header: ➡️ Add/Remove/Append request and response headers. One of example is developer can fix issue like CORS by setting Content-Security-Policy, X-Frame-Options headers and all headers can by change by provide header and value. 👉 Modify Response: ➡️ This cool feature can return custom data from the network. Now is possible to return data types like HTML/CSS/JS/JSON. By choosing one of type developer can write custom code in the editor which has powerful user interface like VSCODE which supports everything that developer need to write code. 👉 Inject File: ➡️ You can easily inject external CSS and JavaScript files into any web page by simply providing the link to the file. This is a great way to quickly modify the style or functionality of a website without needing to manually edit the code. If you want to inject your own custom code into a web page you can enter HTML, CSS, or JavaScript directly into the extension, and it will be injected into the page as if it were part of the original code. 👉 HTTP Logger: ➡️ This feature allows you to easily view and analyze the request and response headers of all tabs in one place, giving you valuable insights into the data being exchanged. 👉 Modify Request Body: ➡️ Now it is possible to modify the request body for both APIs, XMLHttpRequest and Fetch. This new feature allows modification of the body without making any changes to the code. 🙌These all features are free and there isn't any limitation to create a rule.
