PROXYRADAR DEVELOPER GUIDES
How to Check If an IP Is a Proxy or VPN
To check whether an IP is a proxy or VPN, submit its public address to an IP detection tool and inspect the overall result together with the network categories. A positive classification describes the connection; it does not prove that the visitor is malicious.
Check a public IP address in three steps
- Find the address you actually want to assess. For a website visitor, use the client address observed by your trusted server or reverse proxy. Do not blindly trust a user-supplied forwarding header. If you check your server’s own address, you are assessing the server’s network, not the visitor’s connection.
- Open the free proxy checker. Enter the address without a URL scheme, port or proxy credentials. Public IPv4 and IPv6 addresses are supported. A private address used inside a home or office network cannot identify the internet-facing connection.
- Read the overall answer and the available categories. Decide what the classification means for your particular action. A login attempt, an anonymous page view and a server-to-server callback do not need the same policy.
Proxy, VPN, Tor and hosting are different signals
| Signal | Meaning | Common misunderstanding |
|---|---|---|
| Proxy | A connection can be relayed through another server or device. | A proxy label does not establish why the connection is being relayed. |
| VPN | The address is associated with a known VPN network. | A VPN user is not automatically an abusive user. |
| Tor exit | The address is identified as an exit from the Tor network. | An exit address does not reveal the original user’s address. |
| Hosting | The address belongs to a hosting or datacenter network. | Hosting does not prove that a VPN service is running on that address. |
| Known crawler network | The address matches a published range for a supported search crawler. | This is not universal bot detection or proof that a particular HTTP request is authentic. |
These categories can overlap. For example, a Tor exit can run in a hosting network. ProxyRadar’s overall proxy result includes hosting, so read flags.hosting separately if your application needs to distinguish hosting from VPN use.
How to interpret the answer
A positive result with a category
If proxy is 1 and flags.tor is true, the response gives you both the overall classification and a Tor signal. You might ask for additional verification on a sensitive action while still allowing ordinary browsing.
A positive result without a specific category
An IP can receive an overall positive result even when none of the category flags is true. Do not convert that response to a negative result because the VPN flag is false. Use proxy for the overall classification and treat category fields as additional context.
A negative result
A proxy value of 0 means the lookup did not identify a proxy. It does not establish that the connection is residential, that the request came from a human or that the account is trustworthy.
An unavailable result
A timeout, service error or invalid response is an unknown state. Keep it separate from a negative classification. The API error reference explains the status codes your integration should handle.
Can residential proxies or private VPNs be missed?
Yes. A residential proxy uses an address that can resemble an ordinary home connection. New or private VPN endpoints can also be difficult to identify. Network ownership and usage can change, and no IP-only classification proves the identity or intent of a user.
For an application decision, combine the IP result with signals you already have: account history, request rate, authentication state and repeated failed actions. Keep a way to review or appeal a restriction so a changed network classification does not permanently lock out a legitimate customer.
When should you use an API instead of a browser checker?
A browser lookup is useful for support investigations and trying a small number of addresses. An API is a better fit when your own application needs a result during signup, login or a traffic review. See the API evaluation guide and server-side code examples before connecting the result to an automatic rule.
Put the guide into practice.
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