Proxy Configuration

Some CAPTCHAs validate that the solver’s IP address matches the end user’s IP. In these cases, you need to provide a proxy so the solving provider can appear to come from the correct IP. This page explains when and how to configure proxies.

When to Use Proxies

Most CAPTCHA types do not require proxies. The ProxyLess task variants handle everything server-side and are recommended for the majority of use cases.

You should use proxy task variants when:

The target website performs IP matching between CAPTCHA solving and form submission
You are working with CAPTCHAs that enforce strict session-IP binding
The target website blocks known datacenter IPs from solving providers

ProxyLess vs Proxy Task Variants

Each CAPTCHA type that supports proxies has two task type variants:

Variant	Example Type	Proxy Required
ProxyLess	`ReCaptchaV2TokenProxyLess`	No
Proxy	`ReCaptchaV2Token`	Yes

ProxyLess (recommended):

No proxy configuration needed
The solving provider uses its own infrastructure
Lower cost, higher success rate in most cases
Works for the vast majority of websites

Proxy:

You supply proxy credentials in the task object
The solving provider routes through your proxy
Required when the target site performs IP matching
Slightly higher cost and solve time due to proxy overhead

Proxy Parameters

When using a proxy task variant, include these fields in the task object:

Parameter	Type	Required	Description
`proxyType`	string	Yes	Protocol: `http`, `socks4`, or `socks5`
`proxyAddress`	string	Yes	IP address or hostname of the proxy
`proxyPort`	integer	Yes	Port number
`proxyLogin`	string	No	Username for authenticated proxies
`proxyPassword`	string	No	Password for authenticated proxies

Example: reCAPTCHA v2 with Proxy

{
  "clientKey": "YOUR_API_KEY",
  "task": {
    "type": "ReCaptchaV2Token",
    "websiteURL": "https://example.com",
    "websiteKey": "SITE_KEY",
    "proxyType": "http",
    "proxyAddress": "1.2.3.4",
    "proxyPort": 8080,
    "proxyLogin": "user",
    "proxyPassword": "pass"
  }
}

Example: hCaptcha with SOCKS5 Proxy

{
  "clientKey": "YOUR_API_KEY",
  "task": {
    "type": "HardCaptchaToken",
    "websiteURL": "https://example.com",
    "websiteKey": "SITE_KEY",
    "proxyType": "socks5",
    "proxyAddress": "proxy.example.com",
    "proxyPort": 1080,
    "proxyLogin": "user",
    "proxyPassword": "pass"
  }
}

Legacy API Proxy Format

For 2captcha-compatible endpoints (/in.php), pass proxy information as query parameters:

https://api.ucaptcha.net/in.php?key=YOUR_API_KEY&method=userrecaptcha&googlekey=SITE_KEY&pageurl=https://example.com&proxy=user:pass@1.2.3.4:8080&proxytype=HTTP

The proxy parameter format is login:password@address:port or address:port for unauthenticated proxies. The proxytype parameter accepts HTTP, SOCKS4, or SOCKS5.

Proxy Best Practices

Use residential proxies. Residential IPs have the highest success rate because they appear as real users. Datacenter proxies are frequently detected and blocked by CAPTCHA providers.

Avoid free or public proxies. They are slow, unreliable, and likely already blacklisted by most CAPTCHA systems.

Rotate proxies for high volume. Sending too many CAPTCHA solving requests through a single proxy IP can trigger rate limits or bans on the target website.

Match proxy location to your target. If the target website is region-specific, use a proxy in the same geographic region to avoid location-based validation failures.

Test your proxies independently. Before blaming the CAPTCHA solver, verify that your proxy is accessible and returns a valid response through the target website. Common issues include:

Proxy is offline or unreachable
Authentication credentials are incorrect
Proxy is rate-limited or banned by the target
Proxy type mismatch (e.g., sending HTTP traffic to a SOCKS proxy)