curl NO_PROXY Rules for Domains and IP Addresses
Check curl's destination bypass rules, including literal IPs, domain suffixes, CIDR networks, empty lists, and the all-host wildcard.
NO_PROXY describes destinations that should be reached directly. It does not identify proxy servers to avoid. Adding the selected proxy's own IP to the list is not a way to choose whether an unrelated website uses that proxy.
| Entry | Meaning in curl |
|---|---|
example.com | The named domain and matching subdomains bypass the proxy. |
.example.com | A domain-suffix exclusion, including the domain itself. |
192.168.1.10 | A matching literal destination IP bypasses the proxy. |
192.168.0.0/16 | Matching literal IP destinations bypass it; CIDR support requires curl 7.86.0 or newer. |
* | Every destination bypasses the proxy. |
Empty and asterisk are different
For one explicit proxy test, an empty command-line list removes environment bypass matches:
curl --proxy http://203.0.113.10:8080 --noproxy '' \
--connect-timeout 5 --max-time 15 https://example.com/Replace the documentation endpoint with your HTTP proxy or a candidate from the HTTP proxy list. To perform the opposite comparison, the quoted wildcard makes the request direct even though the proxy option is present:
curl --proxy http://203.0.113.10:8080 --noproxy '*' \
--connect-timeout 5 --max-time 15 https://example.com/Keep the wildcard quoted so the shell does not expand it into filenames. Unsetting an environment variable, setting it to an empty value, and supplying a command-line override are separate actions; another applicable setting can remain after you remove only one definition.
CIDR is not a rule for every name that resolves into a network
A CIDR entry is matched against an IP address used as the destination host. It is not a general instruction to resolve every hostname first and bypass the proxy if the answer falls inside that network. A URL using a hostname and a URL using its numeric address can therefore select different routes.
Use hostnames or domain suffixes when that is what the URL contains. Do not put a full scheme, path, or browser bypass expression into this list and assume curl will interpret it the same way.
These rules describe curl 8.14.1. Other clients have their own NO_PROXY behavior, including differences in wildcard and port matching.