How to Use a Proxy with cURL (2026 Guide)

By Marcus Reiner 2026-05-23 6 min read Engineering

cURL + proxy in 30 seconds, or curl-impersonate for true browser fingerprint mimicry. Here's both.

HTTP/HTTPS proxy

```bash curl -x http://user:[email protected]:7777 https://httpbin.org/ip ```

SOCKS5 proxy

```bash curl --socks5 user:[email protected]:1080 https://httpbin.org/ip ```

Sticky session

```bash curl -x http://user-session-abc:[email protected]:7777 https://target.com ```

curl-impersonate for TLS fingerprinting

Standard curl has a unique TLS fingerprint that Cloudflare flags. Use curl-impersonate (https://github.com/lwthiker/curl-impersonate) to mimic Chrome/Firefox exactly.

Common errors

`407 Proxy Authentication Required` → wrong credentials. `Connection refused` → wrong port or firewall. `SSL handshake failure` → outdated curl, upgrade to 8.x.

Read more on ToptierProxy Blog or see our Best Proxies 2026 guide.