Proxy tools that answer real questions
Check a proxy list for the mistakes that break connections, measure latency and download speed, see which IP and network the web actually sees, and catch the headers that leak your proxy. No upload, no account, no limits.
Proxy list checker & code generator
Paste a proxy list in any common format and this tool parses every line, flags the mistakes that break connections, and writes the client code for you. Nothing leaves your browser — the credentials in your list are never transmitted anywhere.
Your proxy list
One entry per line. Accepted: host:port, host:port:user:pass,user:pass@host:port and any of those with an http://,https://, socks4:// or socks5:// prefix.
| Input | Status | Normalised proxy | Auth token | Notes |
|---|---|---|---|---|
http://user:pass@gate.graviix.com:8080 | Valid | http://user:pass@gate.graviix.com:8080 | dXNlcjpwYXNz |
|
gate.graviix.com:8080:user:pass | Valid · duplicate | http://user:pass@gate.graviix.com:8080 | dXNlcjpwYXNz |
|
socks5://user:pass@198.51.100.24:1080 | Valid | socks5://user:pass@198.51.100.24:1080 | dXNlcjpwYXNz |
|
203.0.113.9:3128 | Valid | http://203.0.113.9:3128 | No auth |
|
Ready-to-run snippet
Built from http://user:pass@gate.graviix.com:8080. Use the buttons to switch between the valid entries in your list.
curl -x http://user:pass@gate.graviix.com:8080 \
https://httpbin.org/ipA valid format does not prove the proxy is reachable. Run the snippet once — if it returns a different IP than your own, the proxy is forwarding traffic correctly.
Proxy latency & download speed test
Four latency checks plus a real download measurement, run from your browser. Whatever proxy your device or browser profile is currently using is the route being measured, so run it once with the proxy on and once with it off to see the cost of the proxy.
Results include DNS lookup, TLS handshake and transfer, so they sit higher than a raw ping. Socket-level ping (ICMP) cannot be measured from a browser. Very low numbers on every endpoint usually mean a local cache or a transparent proxy is answering first.
IP, ISP & proxy detection lookup
See the exact address public websites receive, which network owns it, and whether that network is a hosting provider. Use it after enabling your proxy: if the address and operator change, the proxy is working.
HTTP header & proxy leak inspector
Every request carries headers that can give away the proxy in front of it. This tool echoes the headers your browser sends and highlights the ones that expose an intermediary, so you can tell whether your proxy is transparent or anonymous.
Proxy auth Base64 encoder & decoder
Most proxies expect credentials as username:password encoded in Base64. Encode your pair exactly as a client would, or decode a token you found in a config file.
dXNlcjpwYXNzd29yZA==Proxy-Authorization: Basic dXNlcjpwYXNzd29yZA==CIDR & subnet calculator
Work out the network, broadcast address, usable host range and host count for any IPv4 block. Useful when a provider sells IPs by subnet rather than by single address.
- Network
203.0.113.0/29- Subnet mask
255.255.255.248- Wildcard mask
0.0.0.7- Usable range
203.0.113.1 – 203.0.113.6- Broadcast
203.0.113.7- Total addresses
- 8
- Usable hosts
- 6
- First usable
203.0.113.1
Point-to-point links (/31) and single-host routes (/32) have no network or broadcast address, so every address in the block is counted as usable.
A five-minute proxy health check
The order below matches how a connection actually fails: wrong format first, wrong route second, leaks third.
- Validate the list. Paste every line into the checker. Fix anything marked invalid before you debug anything else — a missing port or a private IP accounts for the majority of “dead proxy” reports.
- Confirm the route. Copy the cURL snippet and run it once. If the response IP matches the proxy you supplied, traffic is forwarding. If it matches your own connection, the client is ignoring the proxy setting.
- Measure the cost. Run the speed test with the proxy off, then on. A residential proxy adds latency; if it adds hundreds of milliseconds, the exit node is far from both you and the target.
- Check the fingerprint. The IP lookup shows whether the target sees a residential carrier or a hosting provider. The header inspector shows whether the proxy announces itself with
ViaorX-Forwarded-For. - Only then scale. Once one request behaves correctly, rotate the list in bulk. Re-run the checker after any provider-side password change.
Common questions about these tools
Short answers to what people ask before trusting a browser-based proxy tool.
Can a proxy checker verify that a proxy is online from my browser?
No. Browsers cannot open raw TCP connections, so a web page can never connect to an arbitrary host:port pair the way a desktop client does. The checker on this page validates the format of your proxy list, catches the mistakes that cause most failed connections, and generates ready-to-paste code. To confirm a proxy is alive, send one request through it with cURL or Python using the snippets below. A true liveness check needs a server-side worker.
Does the speed test measure my proxy or my normal connection?
It measures whatever route your device is currently using. If the proxy is configured system-wide or in your browser profile, every request in the test travels through it. If the proxy is only configured inside your scraper, run the test with the proxy enabled in the operating system first, or compare the results with and without it.
Why does my proxy work in cURL but not in the browser?
Most often the scheme is missing. Browsers need http:// or https:// in front of the host, while many proxy lists are published as bare host:port:user:pass. The second common cause is a stale authentication token: some providers rotate the password when you change your IP allowlist. Use the auth encoder to rebuild the credentials and test again.
What do the IP lookup results tell me about my proxy?
The lookup shows the IP address that public websites see, plus the network operator, ASN and approximate location attached to it. Large hosting operators such as AWS, DigitalOcean or Hetzner in the ISP field usually mean a datacenter IP. That is a strong signal but not proof: mobile and residential carriers can also appear on shared infrastructure.
Which headers reveal that traffic is going through a proxy?
The usual suspects are Via, Forwarded, X-Forwarded-For, X-Real-IP and Proxy-Connection. Well-configured residential proxies strip or rewrite them. If your header inspector shows any of these, the target site can see that a proxy is in the path, and some anti-bot systems will score the request as higher risk.
Are these tools free to use?
Yes. Every tool on this page runs free of charge, without an account, and without sending your proxy list to our servers. Proxy parsing, CIDR maths and encoding happen entirely inside your browser. Only the optional lookup, header and speed tests make outbound requests, and they never receive the credentials you paste.
Need proxies that survive the test?
Graviix runs residential, static ISP, datacenter and mobile endpoints across 195+ countries with one API and city-level targeting. Start with a trial balance and scale only when your own numbers say it works.