Capture traffic from a web browser using Postman Interceptor

Postman Interceptor is a browser extension that acts as a companion to Postman. Interceptor enables you to capture API traffic, including requests and cookies, from a web browser. After capturing requests or cookies, you can view and work with them in Postman.

To get started, install the Interceptor extension. You can then start an Interceptor session, which is a time-bound period of traffic capture. You can pause, restart, and stop an Interceptor session, then later start another one. Each session is logged in your Postman History and displays the total session time, a traffic overview, and all traffic captured. When you're finished, you can save captured requests and responses in a collection, or save captured cookies in the Postman cookie jar.

You can also use Postman Interceptor to automatically sync cookies from a web browser to the Postman cookie jar. Learn more about syncing cookies.

Install Interceptor

Use the links below to download and install the latest version of the Interceptor extension for your web browser. Interceptor is available for the following browsers:

• Google Chrome
• Apple Safari
• Mozilla Firefox
• Microsoft Edge

To open the Interceptor extension, select the Interceptor icon in your browser's toolbar.

Start an Interceptor session

Start an Interceptor session to capture traffic and cookies from your web browser. After you stop the session, captured traffic will open in Postman. All communication between Interceptor and Postman is encrypted.

You can't have more than one proxy or Interceptor session running at the same time.

To start an Interceptor session, do the following:

1. Open the Interceptor extension by selecting the Interceptor icon in your browser's toolbar.

2. Make sure the message Ready to capture appears at the bottom of the Interceptor window.

   If the message Interceptor disconnected appears, make sure either the Postman desktop app is running or the Postman web app is open in your browser. Also, in Postman, make sure you are in an internal workspace where you have edit access.

   If you're not running the latest version of the Postman desktop app, or if you're running the desktop app on Linux, you may need to install Interceptor Bridge to use Interceptor.

3. (Optional) On the Capture Requests tab, use the dropdown menus to limit the requests and responses that are captured while the session is active. Postman will capture requests that match the selected criteria and will ignore requests that don't match. You can change the filters at any time during the session:

   • Methods - Limit captured requests to the selected methods.
   • Domains & URL - Limit captured requests to the domains and URLs that match the specified criteria. You can use regular expressions. Select Enter to apply the specified filters. To remove a filter, select the remove icon next to the filter.

4. On the Capture Requests tab, select Start Capture.

   Interceptor starts capturing requests and cookies as you use your web browser. The Interceptor extension shows recent requests and the duration of the session.

5. When you're done capturing traffic, select Stop Capture to end the session.

You can also use the Interceptor extension to automatically sync cookies from your browser to the Postman cookie jar, without having to start an Interceptor session. For more information, see Sync cookies using Postman Interceptor and the Postman proxy.

View Interceptor results in Postman

When you stop an Interceptor session, Postman automatically opens the results in Postman. You can also select View in Postman to open the session results in Postman.

If the Postman web app is open, session results will open in either the web app or the desktop app, depending on which was last connected to Interceptor. If the web app isn't open, results will open in the Postman desktop app.

To view the Interceptor session again later, select History in the sidebar, then select the Interceptor session. You can also select View Past Sessions on the Interceptor session tab.

The Overview tab shows summary graphs of traffic captured in the Interceptor session. Use the dropdown menu to group requests by method, domain, or content type. The header also displays the session start time, session size, duration, and source.

You can work with the Interceptor session results in the following ways:

• To rename the Interceptor session, select the name Interceptor debug session and enter a new name.
• Select the Requests tab to view information about incoming requests and responses, or select the Cookies tab to view information about captured cookies.
• Use the search box to find specific requests or cookies.
• Select the sort icon in the column headers to sort the results in ascending or descending order.
• Use the filter icons in the column headers to filter the list of requests. Postman shows requests that match the selected filters and hides requests that don't match.
• Select a request to view more details.
• Select a request URL to open it as a new API request in Postman.
• To delete a request or cookie, select it and select Delete.
• To add a cookie to the Postman cookie jar, select it and select + Add to Cookie Jar.

Save captured requests to a collection

You can save requests captured during an Interceptor session to a collection.

1. Select History in the sidebar, then select the Interceptor session with the requests you want to save.
2. Select the checkbox next to the requests you want to save, or select the checkbox in the column header to select all requests.
3. Select Save Requests.
4. Select the collection where you want to save the requests, or select New collection to create a new collection.
5. Choose how to organize the requests in the collection. You can select the checkboxes to group the requests in folders organized by Domain name, Endpoints, or both.
6. Select Save.

Install Interceptor Bridge

Depending on which version of the Postman desktop app you're using, you may need to install Interceptor Bridge before you can use Postman Interceptor:

• If you're using the Postman web app, you can skip this step. You don't need Interceptor Bridge.
• If you're on macOS (Postman v10.17.4 or later) or Windows (Postman v10.18 or later), you can skip this step. Interceptor Bridge is built into your version of Postman.
• If you're on Linux (all Postman versions), macOS (Postman v10.16 or earlier), or Windows (Postman v10.17 or earlier), you must install Interceptor Bridge before you can capture requests and cookies.

To check which version of Postman you're using, select the settings icon in the header and select Settings > About.

To install Interceptor Bridge, select Capture requests in the Postman footer. Then select the Via Interceptor tab and select Install Interceptor Bridge.