Skip to contentProxy authentication: user/pass vs IP whitelist
The current s4m service does not offer IP-only authentication or a combined client-IP allowlist mode. A destination IP allowlist is separate from s4m proxy authentication. It does not enable password-free access to the current s4m proxy service.
The two modes at a glance
Both answer the same question — is this client allowed through? — but with very different trade-offs.
Username / password
Keep proxy credentials out of shared code and logs. If exposed, revoke or replace them in your account.
IP whitelist
The current s4m service does not offer IP-only authentication or a combined client-IP allowlist mode. A destination IP allowlist is separate from s4m proxy authentication. It does not enable password-free access to the current s4m proxy service.
Separate access controls
s4m requires proxy credentials. If a destination also restricts source IPs, configure that policy separately; it does not replace proxy authentication.
Rotate and revoke
Keep proxy credentials out of shared code and logs. If exposed, revoke or replace them in your account.
How they differ, and when to use each
This comparison distinguishes credentials from IP-only access rules. Current s4m service: username/password is required; an IP-only rule is not a substitute.
Username/password authentication. Credentials grant access to a proxy connection. They can be used from different networks, subject to account and service policies. Keep secrets out of source control and logs; revoke or replace a compromised pair.
IP-only access. IP-only access authorizes the source address, rather than an individual user. The service must explicitly support this mode. People sharing an allowed NAT address may share access, while a changed address can stop matching the rule.
| Factor | User/pass | IP-only access |
|---|---|---|
| Secret to protect | Yes | No |
| Works on dynamic IPs | Yes | No |
| Portable across networks | Yes | No |
| Best for | Laptops, mobile, CI | Fixed-IP servers |
| Main risk | Credential leak | Shared or changed egress IP |
s4m examples require credentials. A destination allowlist is a separate rule; allocating a dedicated exit IP does not enable password-free s4m access. Related: dedicated IP, s4m proxies, VPN, guides.
curl: authenticated connections
Replace USER:PASS with your generated credentials. api.ipify.org echoes the egress IP the proxy presents.
# --- Username / password --- # SOCKS5 (socks5h routes DNS through the proxy) curl -x socks5h://USER:[email protected]:1080 https://api.ipify.org # HTTP / HTTPS curl -x http://USER:[email protected]:3128 https://api.ipify.org # Placeholders only. Real command-line credentials may appear in history or process lists. curl --proxy http://proxy.s4m.online:3128 \ --proxy-user USER:PASS https://api.ipify.org
Setting it up on s4m
Generate proxy credentials
Use your account to create or retrieve proxy credentials. Check the applicable plan and access entitlements before connecting.
Verify the connection
Use your account’s host, port and issued credentials. Verify a request through the proxy before running the workload.
Point your client at an endpoint
Configure SOCKS5 (1080) or HTTP (3128) with username/password. For a selected exit location, use the endpoint shown in your account configuration.
Test, then watch usage
Run the curl checks above to confirm the egress IP. Billing is metered pay-as-you-go, and admin-tunable usage limits apply per account and per IP.
Questions, answered
Can I use username/password and IP whitelist at the same time?
The current s4m service does not offer IP-only authentication or a combined client-IP allowlist mode. A destination IP allowlist is separate from s4m proxy authentication. It does not enable password-free access to the current s4m proxy service.
Which method is more secure?
s4m requires proxy credentials. If a destination also restricts source IPs, configure that policy separately; it does not replace proxy authentication.
My server's IP keeps changing — what should I use?
Configure SOCKS5 (1080) or HTTP (3128) with username/password. For a selected exit location, use the endpoint shown in your account configuration.
Do both methods work with SOCKS5 and HTTP?
s4m SOCKS5 (1080) and HTTP (3128) require username/password authentication. An IP allowlist on a destination is a separate policy and does not replace these credentials.
Are the free public proxies authenticated too?
The free list is a separate collection of third-party endpoints. Its checks are point-in-time results, not availability guarantees. s4m service credentials do not authenticate you to entries in that list. See /free-proxies/.
Set up authenticated proxies
Configure s4m SOCKS5 or HTTP access with the credentials from your account.
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