Is 18.163.33.4:51372 a proxy? Yes.
18.163.33.4:51372 is a public HTTP proxy in the HProxy free proxy list, exiting from Hong Kong SAR China. It holds a spotty 12% uptime, and was last checked 6 h ago.
uptime
Hong Kong SAR ChinaOther ports on this IP
18.163.33.4 is answering on 280 ports right now.
Ports like this one rarely travel alone. We hold 283 of them on 18.163.33.4 and have run 673,991 checks against them since May 13, 2026. When an address turns up on public lists across this many ports, each port is published as its own entry, so each one gets its own record here.
Best responding ports
Best on this IP is 18.163.33.4:25450 at 15.7% across 4,677 checks
| Port | Uptime | Answered | Status |
|---|---|---|---|
| 25450 | 15.7% | 733 / 4,677 | In the live pool |
| 53621 | 15.2% | 710 / 4,662 | In the live pool |
| 54960 | 15.0% | 669 / 4,451 | In the live pool |
| 16017 | 14.9% | 697 / 4,663 | In the live pool |
| 55845 | 14.9% | 667 / 4,470 | In the live pool |
| 8072 | 14.8% | 656 / 4,429 | In the live pool |
| 14441 | 14.8% | 661 / 4,476 | In the live pool |
| 731 | 14.7% | 657 / 4,463 | In the live pool |
| 38278 | 14.7% | 646 / 4,393 | In the live pool |
| 2053 | 14.6% | 653 / 4,464 | In the live pool |
| 9899 | 14.6% | 654 / 4,472 | In the live pool |
| 8008 | 14.6% | 648 / 4,448 | In the live pool |
How this one compares
3,884 checks in, its uptime is ordinary for a free proxy.
Every free proxy list quotes an uptime figure. Almost none of them tell you what a normal one looks like, so here is ours: across the 10,492 proxies answering right now, the middle of the pack answers 47.5% of the checks we send it.
12%
of 3,884 checks answered
Pool median 47.5%. 18.163.33.4:51372 sits below it, which is ordinary for a public proxy.
3,884
real connection attempts
Each one opens a socket and waits up to 90 seconds. Slow and unreachable look identical if you stop listening early.
72
days tracked, still in the live pool
Of the 216,950 free proxies we have watched stop working, half were gone within 27 days of us first seeing them.
What normal looks like
Every number above is measured against these two.
A percentage on a proxy list means nothing without the shape of the thing it came from. These are the two distributions the rest of this page compares against, drawn from HProxy's own checks rather than from anybody's marketing page.
How long one lasts
Days from the first time we saw an address to the last time it answered, across 216,950 endpoints that stopped working.
Middle halfMedianFull range
How quickly one answers
Response time on the last successful check, across the 10,492 proxies answering right now.
Where this address sits
Right now our free pool holds 5,562 other free proxies on Amazon, and 2,056 in Hong Kong SAR China. 18.163.33.4:51372 sits inside that set, so if it is not usable the pages below are where its closest alternatives are.
Amazon.com, Inc. is the 4th largest source of free proxies we have ever measured.
Open proxies cluster rather than spreading evenly across the internet. Hosting providers and cloud platforms run enormous numbers of near-identical servers, so a handful of networks end up carrying a disproportionate share of every public proxy list, including ours. HProxy tracks 40,115 addresses on AS16509, which is 5.3% of every address in the database and a substantial share of everything HProxy tracks. That makes it the 4th largest source of free proxies of every network we have ever seen. 5,563 of them are answering right now, so if this particular address is not usable, the network is a reasonable place to look for one that is.
- Answering now14%
- Answered before72%
- Never answered14%
- 1LimitedNetwork-ASAS213790227,474
- 2SECURED SERVERS LLCAS1943779,186
- 3SECURED SERVERS LLCAS2045440,939
- 4Amazon.com, Inc.AS1650940,115
- 5Cloudflare, Inc.AS1333522,905
- 6M247AS900918,000
- 7Cloudflare, Inc.AS20924214,271
- 8Alibaba (US) Technology Co., Ltd.AS4510212,211
How to use this proxy
Route a request through 18.163.33.4:51372 over HTTP. Free proxies are shared and rotate out fast, so test before you rely on it.
curl -x http://18.163.33.4:51372 \
https://api.ipify.org?format=json
Not a terminal person? Pick your device and we walk you through it, nothing assumed.
Continuous monitoring
How HProxy checks 18.163.33.4:51372
18.163.33.4:51372 is in the live pool right now, and it stays there only for as long as it keeps answering.
Port 51372: Ephemeral port range
This is a throwaway port number, the kind a computer hands out for a few minutes and then takes back. Anything published on one tends to move or disappear when its host restarts, which is a large part of why public proxy lists rot so fast.
Every check is a real connection
HProxy does not read this address off somebody else's list and pass it on. Each check opens a real connection to 18.163.33.4:51372 and gives it up to 90 seconds to answer. Slow is not the same as unreachable, and plenty of working proxies take half a minute to reply. Anything that does not answer in that budget counts as a failure and is recorded as one, which is why the percentage on this page moves rather than sitting at a marketing number. The handshake is attempted across HTTP, HTTPS, SOCKS4 and SOCKS5, which is how we know it spoke HTTP.
3,884 checks, 477 answered
That is 12% of the time, measured since June 23, 2026. Every one of those results, successes and failures alike, is a connection HProxy opened itself.
It is being re-tested continuously
18.163.33.4:51372 is in the live rotation, so it is re-tested continuously rather than on a daily cycle. If it stops answering it is marked down immediately, and if it stays down for 3 days it moves into the public proxy database with its full record intact. Nothing is deleted at any point.
This endpoint
The record
Everything HProxy holds on 18.163.33.4:51372, and nothing it does not.
- First seen
- June 23, 2026
- Last checked
- September 3, 2026
- Next check due
- continuously
- Checks run
- 3,884
- Times it answered
- 477
- Spoke
- HTTP
12%
answered 477 of 3,884 checks
Questions about 18.163.33.4:51372
Is 18.163.33.4:51372 a working proxy right now?
Yes. 18.163.33.4:51372 answered HProxy's automated check 6 h ago and is in the live free proxy pool as we publish this page. It is re-tested every few minutes, so open this page again for its current state rather than trusting a copy of it.
What kind of proxy is 18.163.33.4?
It speaks HTTP. The port is 51372. Point your client at 18.163.33.4:51372 over http to route a request through it.
Where is 18.163.33.4 located?
Traffic through it exits from Hong Kong, Hong Kong SAR China, on Amazon.com, Inc. (AS16509). That is where the destination site will think your request came from.
How reliable has 18.163.33.4:51372 been?
Across 73 days of tracking it answered 12% of our checks. The chart on this page shows every day we have recorded for it, including the days it was down.
Is it safe to use 18.163.33.4:51372?
Treat it the way you would any public proxy: it is operated by someone we have no relationship with, it is shared with strangers, and anything you send unencrypted over it can be read. Fine for a quick geo check or a scrape of public data, never for logins, payments or anything private.
How many free proxies are on Amazon?
5,562 other free proxies are live on Amazon (AS16509) in our pool right now, alongside 18.163.33.4:51372. Networks that host one open proxy usually host several, which is why the whole AS is worth browsing rather than just this address.
Are there other free proxies in Hong Kong SAR China?
Yes, 2,056 free proxies are exiting from Hong Kong SAR China in our pool right now, answering in 1268ms at the median. If this address is not usable, that list is the place to look for a working one.
Where to go next
Upgrade to the paid network
Free proxies fail. This is what that looks like.
18.163.33.4:51372 answers 12% of the time, and that is ordinary for a public proxy. Nothing here is a service anybody sells you, which is why the numbers swing and why the list turns over constantly.
Other live free proxies
View all
About this list & IP removal
Every proxy here is aggregated from publicly available sources. We do not scan or collect these IP addresses ourselves: we verify entries that are already public (live status, latency, uptime) and store nothing else about the devices behind them. The list is provided as-is, with no warranty, for lawful use only, on the basis of our legitimate interest in a free, transparent proxy directory (Art. 6 (1) (f) GDPR). Never route passwords or sensitive data through a public proxy. If an IP address is yours and you'd like it removed, email legal@hproxy.com and we'll take it down (Art. 21 GDPR). Full details on the report abuse page.