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If you're new to Sauce Connect Proxy or troubleshooting, this list of FAQs can help you with what you need to know.

Sauce Connect Proxy Frequently Asked Questions:

What Outbound Ports Do I Need Open for Sauce Connect Proxy?

Sauce Connect can only communicate with Sauce Labs via port 443 and port 80. This is not configurable.

How Can I Share a Tunnel Between Multiple Accounts?

To share a tunnel, start a tunnel with the --shared-tunnel flag.  For most Sauce Labs customers, your access to shared tunnels is determined by the permissions of the user who creates them. Organization admins can create tunnels that any user on any team can use. Team admins can create tunnels that any member of their team can use. Team members cannot share tunnels they create with any other team member. 

NOTE: In very limited circumstances, your Sauce Labs license might include sub-accounts. Sub-accounts must specify the parent tunnel in the desired capabilities of their test in order to use the tunnel. For details about test configuration options, see Shared Tunnels.

How Can I Use Sauce Connect Proxy to Test Graceful Degradation?

You can use the --fast-fail-regexps command-line option to drop requests that fit a description altogether. It can be used to simulate non-loading of scripts, styles, or other resources.
This flag can contain a list of regex that will match the domain that wants to be blocked.

For example, by entering this line – (www.)?,(www.)?,([a-z0-9]+[.])*,([a-z0-9]+[.]) – you will block the following domains:

  • and any subdomain of
  • any subdomain of, but not

Can I Access Applications on localhost?

When using Sauce Connect Proxy, local web apps running on commonly used ports are available to test at localhost URLs, just as if the Sauce Labs cloud were your local machine.

However, because an additional proxy is required for localhost URLs, tests may perform better when using a locally defined domain name (which can be set in your hosts file) rather than localhost. Using a locally defined domain name also allows access to applications on any port.

Android Ports and Sauce Connect

 On Android devices, ports 5555 and 8080 cannot be used with Sauce Connect Proxy

Supported Browsers and Ports

The following commonly used browsers and ports are subject to change as new versions are released: 

Microsoft Edge, Chrome 71+ and the Safari browser on OS X 10.10+ and mobile iOS 8+ proxy these common ports:

80, 443, 888,
2000, 2001, 2020, 2109, 2222, 2310,
3000, 3001, 3010, 3030, 3210, 3333,
4000, 4001, 4201, 4040, 4321, 4502, 4503, 4567,
5000, 5001, 5002, 5050, 5555, 5432,
6000, 6001, 6060, 6666, 6543,
7000, 7070, 7774, 7777,
8000, 8001, 8003, 8031, 8080, 8081, 8443, 8765, 8777, 8888,
9000, 9001, 9031, 9080, 9081, 9090, 9191, 9876, 9877, 9999,
49221, 55001

If We Have Five Users, Can We Use Five Instances of Sauce Connect Proxy? Or Do We Have to Set Up One Shared Instance?

Feel free to use either, even if you only have one Sauce account! If you do decide to use five separate instances, you will need to create unique identifiers for each. For more info on tunnel identifiers, see High Availability Sauce Connect Proxy Setup.

Can I Split Testing Traffic Across Multiple Sauce Connect Proxy Tunnels?

Sauce Connect Proxy offers some options for high availability that enable multiple Sauce Connect Proxy tunnels to be grouped into a pool, which is treated like a single tunnel. This has several advantages, including the ability to distribute the load of test traffic. For more information, see High Availability Sauce Connect Proxy Setup.

Do You Support Running XCUITest and Espresso Tests with Sauce Connect Proxy?

Yes. For more information, see Mobile Testing Frameworks.

How Many Sauce Connect Proxy Tunnels I Can Have Open?

Your options depend on your license type. For more information, see System and Network Requirements for Sauce Connect Proxy.

Is There Any Limit on How Many Tests I Can Run Per Tunnel?

There are currently no limits on how many tests you can run in each tunnel, though we may eventually implement limitations to maintain service quality. For more information, see System and Network Requirements for Sauce Connect Proxy.

Are There Any Limits on Who Can Use the Sauce Connect Proxy Tunnels for Real Devices?

No, tunnels to the Real Device Cloud are automatically shared with all of your team members. 

I Have a Single Machine That I Use to Run Sauce Connect Proxy Tunnels, Can I Run Tunnels to the Real Device Cloud on the Same Machine?

You can run a Sauce Connect Proxy tunnel for web testing and a separate tunnel for the Real Device Cloud on the same machine. However, you will need:

Is There Any Difference with PAC File Configuration for Real Device Tests?

No, though you cannot use the localhost address with iOS.

Will Sauce Connect Proxy Work with Dynamic Allocation of Real Devices?


Why Does Sauce Labs Recommend Using Sauce Connect Proxy Instead of Whitelisting IP Addresses?

Generally, Sauce Labs recommends using Sauce Connect (or IPSecVPN) instead of whitelisting IP ranges. Please read the following page for further information: Why Sauce Labs Recommends Sauce Connect Proxy Over Whitelisting IP Addresses.

1 Comment

  1. In addition to these, Sauce Connect Proxy requires a localhost port for the Selenium relay (see --se-port for details) and SCProxy (see --scproxy-port for details), both of which are configurable.
    These ports are not outbound though, so I don't think this should be mentioned in this section.