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Sauce Connect Proxy system requirements vary, depending on the number of parallel tests you plan to run.

Please keep in mind that these are guidelines. Most environments have their own workload requirements for optimal performance. Test and profile your own environment using these recommendations as a baseline.

See the following sections for more information:

What You’ll Need

All Users

Prior to getting started with Sauce Connect Proxy, you'll need to verify Sauce Connect Proxy network routes on your host machine.

macOS Catalina 10.15 Users

Sauce Connect supports macOS Catalina 10.15, however, you'll need to enable your Mac to allow apps from the App Store and identified developers.

REQUIRED: To ensure compatibility, prior to downloading Sauce Connect, head to System Preferences > Security & Privacy > General tab. Under the header "Allow apps downloaded from," select the option "App Store and identified developers."

System Requirements

Configuring Your System to Use Sauce Connect

In the table below, select a cloud provider to view the recommended system requirements:

Parallel TestsMachine TypeMemory


BandwidthRecommended SC Tunnels
0-99EC2 m4.large8GB2450 Mbps1
100-199EC2 m4.xlarge16GB4750 Mbps1
200-399EC2 m4.xlarge16GB4750 Mbps2
400-599EC2 m4.xlarge16GB4750 Mbps3
600-799EC2 m4.xlarge16GB4750 Mbps4
800+EC2 m4.xlarge16GB4750 Mbps6
Parallel TestsMachine TypeMemory


BandwidthRecommended SC Tunnels
0-99GCE n1-standard-27.5GB2450 Mbps1
100-199GCE n1-standard-415GB4750 Mbps1
200-399GCE n1-standard-415GB4750 Mbps2
400-599GCE n1-standard-415GB4750 Mbps3
600-799GCE n1-standard-415GB4750 Mbps4
800+GCE n1-standard-415GB4750 Mbps6

Coming soon!

Parallel TestsMachine TypeMemory


BandwidthRecommended SC Tunnels
0-99EC2 m5.large7.5GB23.5Gbps1
500-999EC2 m5.large7.5GB23.5Gbps2
1000-1999EC2 m5.large7.5GB23.5Gbps4
2000+EC2 m5.large7.5GB23.5Gbps8

Parallel TestsMachine TypeMemory


BandwidthRecommended SC Tunnels
0-99GCE n1-standard-2
500-999GCE n1-standard-2 
1000-1999GCE n1-standard-2 
2000+GCE n1-standard-2 

Coming soon!

Here are some rules of thumb to help ensure the best Sauce Labs testing experience:

  • When running 100 or more parallel tests in Sauce Connect Proxy, we recommend a minimum network bandwidth of 750Mbps to support the high volume of network traffic
  • When running 200 or more parallel tests, we recommend launching more than one tunnel. If you're using more than one tunnel, we recommend the High Availability Sauce Connect Proxy Setup
  • When running a high volume of parallel tests on Unix-based operating systems, you may need to increase your open file limit (for example, ulimit -n 8192)
  • For optimal reliability, performance, and security, we recommend using a dedicated server. For more information, please see Sauce Connect Proxy and Network Security

Sauce Connect Must Be Set Up on Same Network as Test Device(s)

IMPORTANT: Sauce Connect doesn't need to be set up on the same machine as the website or app you're testing, however, it must be on the same network.

What Not to Do: Common Mistakes in Sauce Connect Proxy Network Configurations illustrates some examples of network architectures in which Sauce Connect will not be able to create a tunnel or will be too slow to carry out effective testing.  

Network Requirements

Configuring Your Network to Use Sauce Connect

In order for Sauce Connect proxy to work correctly, your network administrator may have to update firewall or proxy settings on your network. Prior to getting started, we recommend evaluating your organization’s network security for firewall restrictions, which may interfere with testing.

The Sauce Connect proxy client that runs on your network makes three types of outbound connections during tunnel startup:

  • Communication to the Sauce Labs REST API tunnels endpoint, to request a new tunnel

  • Communication to third-party web sites of Certificate Authorities, in order to validate the REST API certificate

  • Communication to the Sauce Connect “Tunnel VMs” in the Sauce Labs Cloud, to establish the tunnel

The client makes two types of outbound connections when tests are running:

  • Communication to the Sauce Labs REST API tunnels endpoint to pass status information

  • Communication to the sites specified by your tests

Regardless of whether or not you use Sauce Connect, you may also need to whitelist outbound traffic to the Sauce Labs Selenium/Appium endpoints. 

If outbound communication from your network is restricted, you can whitelist the appropriate domains for outbound communication. When using Sauce Connect, you do not need to do any whitelisting for communication coming into your network (inbound traffic).

Whitelisting for Restricted Networks

If you're testing in a restricted network setting, you might need to whitelist the Sauce Labs domains below for outbound communication. 

NOTE: To determine if this is needed, refer to Validating Your Basic Sauce Connect Proxy Setup

Be sure to use the set of domains for the Sauce Labs Data Center you are using: US Data Center (US-WEST-1), Headless Data Center (US-EAST-1), or European Data Center (EU-CENTRAL-1). To confirm which Data Center you are using, log into the Sauce Labs web application and view the data center in the upper right-hand corner of the page.

Sauce Labs REST API Endpoints

The Sauce Labs REST API is a requirement for using Sauce Connect Proxy. Please select the relevant data center:

Sauce Connect Tunnel Service Domains

The following domains must be whitelisted for outbound communication from you network  in order to make connections to Sauce Connect Tunnels. Please select the relevant data center:

Recommended Wildcard Whitelisting

All DCs, VMs, or RDC: * will cover everything (apart from headless).

Recommended Wildcard Whitelisting

All DCs, VMs, or RDC: * will cover everything (apart from headless).

Recommended Wildcard Whitelisting

All DCs, VMs, or RDC: * will cover everything (apart from headless).

Certificate Management

Public key certificates are used to manage the security of Sauce Connect communication to both the Sauce Labs API and to the Virtual Machine hosting your tests in the Sauce Labs cloud. For certificate authentication, the server hosting Sauce Connect may need to connect to Online Certificate Status Protocol (OCSP) and/or Certificate Revocation List (CRL) services. 

For further information on verifying built-in certificates, see Sauce Connect Proxy Certificate Handling.