XHR Request Interceptor

Browser Proxy

Replace fetch, XMLHttpRequest, AJAX responses on the fly! Browser-Proxy allows you to mock responses of AJAX requests without leaving the browser on pages where you enabled it. You can choose what requests shall be overwritten, or even mock not yet existing APIs. You can change the response, status code, delay, response headers, set up chunking and use parts of the request as part of the response. It also lets you to share these mocks with someone though import and export, and all of this with a nice UI. - Change the response of fetch, XMLHttpRequest, Axios and other AJAX requests on the fly. - Mock Responses of not yet existing requests. - RegExp based rules for url, body or headers to decide what requests to override. - Import and export the overrides into JSON file to share in team. - Individual enabling and disabling of overrides on different sites, and grouping into folders. - Part of the request can be used as part of the response. - Mock file download interactions with chunking and custom delays. - Works offline. - Open source. For more details and documentation and source code visit: https://github.com/Vladislav-Boiko/browser-proxy -------------------------------------------- Change notes: 1.0.3 Added response highlighting and negation filter, fixed chunks duplication and variables removement bugs 1.0.2 Fixed communication between background scripts and popup in chrome v95+ 1.0.1 Removed permissions for clipboard copy according to the google review process 1.0.0 initial release

ModResponse - Mock and replay API

Mock, modify, and replay API. Easy setup. No proxy needed. No code change required. ModResponse is a powerful and easy-to-use tool for web developers that simplifies the process of modifying, stubbing, and replaying HTTP responses. It requires no extra proxy or code change to be made, allowing you to quickly and conveniently test different scenarios and debug edge cases. With ModResponse, you can modify the API response, return different HTTP status code, add delay to your request, etc. You can also reroute your HTTP request to a different server, allowing you to test your local changes in production domain within seconds, without the risk of breaking production. ModResponse does not require extra proxy or making any code change. It can modify pretty much any HTTP request, not just XHR requests. Simply install it and you are ready to go! ** What can ModResponse do?** - Record and replay HTTP response - Stub HTTP response - Reroute request to a different URLs - Change HTTP response body, status code, and headers - Delay HTTP requests to simulate slow network - Simulate network errors - Advanced filtering by tab, tab group, window, or time - Demo with fake data Want to create perfect data for your product demo? With ModResponse, you can replace the actual API response with a fake one that contains the data you want. No need to change your real data or make code change. - Speed up slow requests Do you have API requests that are taking a long time to finish, and every time you make a small UI tweak you need to wait >10 seconds for the API request to finish to visualize your change? Using replay response, you can record and replay the slow API request. That way, you will only need to wait on the slow API request once. All subsequent requests to be served from the cached response within a few milliseconds. - Develop against edge cases Need to handle a 4XX or 5XX status code from an XHR request, or try out how your UI will behave with a very long string? Using replay response or stub response, you can modify the response body, status code, or response headers to simulate different scenarios that you need to handle. - Develop against unimplemented APIs Are you a web developer who is blocked because an endpoint you depend on is not yet implemented? Using stub response, you can mock the API response so you can start developing against that endpoint. That way, you can develop the frontend while others implement the endpoint (as long as the actual implementation return the response in the same format). - Testing on production domains Do you need to integrate with a third party platform that only works on your production domain? Using proxy request, you can reroute the request from your production domain to localhost or a dev domain, allowing you to test your changes on your production domain without the risk of breaking it. - Debug edge cases Need to test how your app behaves when some resources takes too long to load, or when they fail to load due to network errors? With ModResponse, you can add artificial delay and simulate different network error conditions so you can debug and handle edge cases with ease. ** Other ModResponse features ** - Support having multiple profiles with quick switching between profiles - Export and import profile - Easily share your profiles with others - Dark mode support - Customizable profile badge - Clone profile ...and more!!! "debugger" is required in order for response modification to work. "tabs" permission is required for prefilling the URLs, and for tab filter, tab group filter, and window filter to work. "storage" and "unlimitedStorage" are required to store the response modification. "contextMenus" is used to enable quick pause/unpause by right-clicking on the icon. ** Known issues ** 1, You will see ["ModResponse" started debugging this browser] banner when ModResponse is activated. This is because it uses the debugger API, which is needed for response modification. Due to Chrome's security policy (https://crbug.com/1096262), that banner would show up on all tabs even when a tab is not being modified, and it may still for a few more seconds after ModResponse is paused or disabled. To hide it, you can run chrome with --silent-debugger-extension-api command line switch. 2, Clicking on the "Cancel" button on the ["ModResponse" started debugging this browser] banner will not deactivate ModResponse. To deactivate it, please open ModResponse and click on the "Pause" button. Once paused, the banner should disappear in a few seconds.

Requestly: Intercept & Modify HTTP Requests

Intercept & modify HTTP(S) traffic: redirect URLs, modify headers, inject scripts, mock REST & GraphQL APIs, and more. 🚀 Best Chrome extension to supercharge Web Development & QA. Trusted by 300,000+ developers. 👉 Requestly works directly in Chrome with beautiful, modern UI and team collaboration features. Popular features – Modify HTTP Headers, Override API Responses, API Mocking, Redirect URLs, Insert Scripts & HTTP Interceptor. 🌟 Top Use Cases → Mock API Responses to build frontend when backend isn't ready → Modify HTTP Request & Response Headers → Test local JavaScript changes directly on production sites → Use HTTP Redirect Rule to load scripts from local or staging environments on production sites → Modify and Mock API Request payload, Response body, & Status Code → Override GraphQL Requests 📌 https://requestly.com/blog/what-is-requestly Requestly (now a part of BrowserStack) doesn't set up a proxy in your browser, and hence, developers don't face VPN issues or lags while using it. Requestly leverages Chrome Extension APIs under the hood to intercept & modify requests. 👉 Redirect URLs, Change Host, Modify Query Params (Map Remote or Map Local) → Use dev/staging APIs in production sites & test local changes without code changes → Debug remote Javascript by loading locally running JS in production sites → Switch Hosts (e.g. abc.com/* to xyz.com/*) using Replace Rule → Debug Ad Tracking Pixels, Debug A/B Test Campaigns, etc → Remote Debugging with Requestly on Production sites → Swap Adobe Launch (Adobe DTM) scripts in production with staging script 📌 Demo Video – https://www.youtube.com/watch?v=85GVaOWTnlE 👉 Insert Scripts to any Webpage → UserScripts are simple JavaScript/CSS code that can change the layout of a page, add or remove new functionality and content, or automate actions. → Use File Server to upload long scripts and Inject them using Script Rule → Inject your JS tags on potential customers' sites and test your features → The sales/product team can use this to demo the product directly on the prospect's website (10x engaging demo) 📌 Demo – https://www.youtube.com/watch?v=4dvucRjLwGY 👉 Requestly supports the following imports → All HTTP header profiles from ModHeader → JSON configuration for Redirects & Scripts from Resource Override → XML configuration from Charles Proxy (Map local isn't supported in chrome extension yet due to technical limitations in browser) 👉 Additional Features → Enable/Disable rules with a single click → Export and import the rules and maintain a backup for your rules → Easy collaboration with others. Share Rules with other Users in one click 📌 Demo – https://www.youtube.com/watch?v=BM7kTFy-vdc

Receptor

Intercept and modify fetch/xhr requests and responses on browser Receptor helps you intercept, inspect, and modify fetch and XHR requests and responses directly in Chrome, making it easier to debug APIs, test frontend behavior, and simulate backend changes without touching server code. Built for developers, QA engineers, testers, and API integrators, Receptor gives you fine-grained control over browser network traffic in real time. You can update request headers, response headers, request bodies, response bodies, query parameters, status codes, and delays using flexible matching rules based on URL, HTTP method, and other request details. Receptor is useful for API testing, frontend debugging, mocking responses, validating error handling, simulating alternate server behavior, and testing edge cases before release. Instead of changing your backend or setting up a separate proxy, you can modify live browser traffic directly where your application runs. What you can do with Receptor: - Intercept and modify fetch and XMLHttpRequest traffic - Edit request and response headers - Replace or update request and response bodies - Rewrite query parameters before requests are sent - Change response status codes - Simulate delayed responses and test loading states - Organize rules with scenarios and groups - Import and export local configurations - Create advanced request and response transformation workflows Receptor is designed for modern web development workflows and is especially helpful when working with SPAs, REST APIs, internal tools, staging environments, and frontend-heavy applications that rely on dynamic network requests. - Debug API integrations faster - Test frontend changes without backend deployment - Simulate success, error, and edge-case responses - Validate request payloads and headers - Reproduce bugs caused by specific API responses - Improve QA and regression testing in the browser If you need a flexible browser extension for request interception, response modification, API debugging, frontend testing, and network mocking, Receptor gives you a practical way to control fetch and XHR traffic directly inside Chrome.