Open Source

Intercept & modify API responses on the fly

Test edge cases in your app by simulating API responses‍.

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Override XHR/fetch Response

Using Requestly Modify Response rule, you can override the API responses triggered by XHR/fetch. No need to hardcode API responses in frontend code anymore.

Test error paths in your code

Modify API responses to trigger different error paths in your codebase and test the flows without changing anything on backend. e.g. Simulate Payment Timeout Issue, Item out of stock Issue, etc.

1-Click Sharing

Use-Cases in teams are very similar so Requestly makes it easier to share the rules with each other and collaborate faster.

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Application and use cases

Here’s how you can use Requestly’s Modify Response feature in your daily workflow

Static Response

Allows you to intercept and replace the original server response with a predefined fixed JSON or string response

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Dynamic response

Gives ability to modify the server response programmatically using JavaScript. Write custom JavaScript code that runs on the intercepted response and manipulate its content.

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Fake status code

Enables you to change the HTTP status code of a server response. By modifying the status code, you can simulate different server responses without actually altering the content.

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Intercept & Modify HTTP Requests

Boost Your Web Development: Advanced Tools for Seamless Debugging.

Redirect URL (Map Remote)

Redirect a request URL to another URL. e.g. Load local scripts in the production sites for faster debugging.

Override API Response

Test edge cases in your app by simulating API responses‍. Override XHR, fetch and AJAX responses.

Inject Custom Scripts

Add Custom JavaScript (JS) to Hide unwanted sections, add action buttons, inject your own libraries, etc.

Modify HTTP Headers

Add, Delete, Override Request & Response Headers. Can be used to remove X-Frame-Options, Content-Security-Policy, CORS Issues, etc.

Modify Query Params

Insert, Modify or Delete query parameters for URLs (or matching pattern). Burst cache for a request by assigning it a newer version.

Delay HTTP Requests

Simulate lag / delay to the response from specific URLs in a single click by using Requestly’s Delay Request Rule. No need to modify actual server.

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An open-source platform that speeds up your web development cycle 10X faster.

Session Recording

Data rich bug reporting with Network logs, Console logs, Session Video and environment details. Share it with your Engineering team for faster debugging.

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Mock API Server

Generate custom API responses without actually having a pre-built API or a backend server. Edit Content-Type, Status Code, Headers, and Response body easily on the Mock Server.

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Web-based API Client

A comprehensive and web-based tool for modifying and testing APIs. You can test the Mock APIs you’re creating here to fast track your development lifecycle.

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Open Source

Intercept & modify API responses on the fly

Override XHR/fetch Response

Test error paths in your code

1-Click Sharing

Trusted by developers at

Application and use cases

Static Response

Dynamic response

Fake status code

Intercept & Modify HTTP Requests

Redirect URL (Map Remote)

Override API Response

Inject Custom Scripts

Modify HTTP Headers

Modify Query Params

Delay HTTP Requests

More from Requestly

Session Recording

Mock API Server

Web-based API Client

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And Our
Marquee Angels

Open Source

Intercept & modify API responses on the fly

Override XHR/fetch Response

Test error paths in your code

1-Click Sharing

Trusted by developers at

Application and use cases

Static Response

Dynamic response

Fake status code

Intercept & Modify HTTP Requests

Redirect URL (Map Remote)

Override API Response

Inject Custom Scripts

Modify HTTP Headers

Modify Query Params

Delay HTTP Requests

More from Requestly

Session Recording

Mock API Server

Web-based API Client

And Our Marquee Angels

And Our
Marquee Angels