Is 47.251.87.199:4145 a proxy? Yes.
47.251.87.199:4145 is a public SOCKS4 proxy in the HProxy free proxy list, exiting from United States. It holds a spotty 5% uptime with a high 3650ms response time, and was last checked yesterday.
Other ports on this IP
47.251.87.199 is answering on 6 ports right now.
Ports like this one rarely travel alone. We hold 34 of them on 47.251.87.199 and have run 134,474 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 47.251.87.199:111 at 8.5% across 4,555 checks
| Port | Uptime | Answered | Status |
|---|---|---|---|
| 111 | 8.5% | 389 / 4,555 | Not responding |
| 999 | 7.5% | 364 / 4,855 | Not responding |
| 1234 | 7.5% | 349 / 4,679 | Not responding |
| 4443 | 7.1% | 338 / 4,780 | Not responding |
| 5060 | 7.0% | 319 / 4,580 | Not responding |
| 2000 | 7.0% | 323 / 4,647 | Not responding |
| 9098 | 6.9% | 336 / 4,895 | In the live pool |
| 2083 | 6.8% | 317 / 4,683 | Not responding |
| 1080 | 6.8% | 309 / 4,568 | Not responding |
| 1036 | 6.7% | 307 / 4,568 | Not responding |
| 50 | 6.6% | 300 / 4,539 | Not responding |
| 312 | 6.6% | 309 / 4,703 | Not responding |
How this one compares
4,258 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 5,626 proxies answering right now, the middle of the pack answers 27% of the checks we send it.
5%
of 4,258 checks answered
Pool median 27%. 47.251.87.199:4145 sits below it, which is ordinary for a public proxy.
3650ms
on its last response
Pool median 8,270ms, so this one is roughly 2x quicker than typical.
90
days tracked, still in the live pool
Of the 271,786 free proxies we have watched stop working, half were gone within 26 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 271,786 endpoints that stopped working.
Middle halfMedianFull range
How quickly one answers
Response time on the last successful check, across the 5,626 proxies answering right now.
Where this address sits
Right now our free pool holds 27 other free proxies on Alibaba, and 17,282 in United States. 47.251.87.199:4145 sits inside that set, so if it is not usable the pages below are where its closest alternatives are. At 3650ms it answers faster than the 4253ms median for United States proxies (about 86% of it).
Alibaba (US) Technology Co., Ltd. is the 8th 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 12,248 addresses on AS45102, which is 1.6% of every address in the database and a substantial share of everything HProxy tracks. That makes it the 8th largest source of free proxies of every network we have ever seen. 28 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 now<1%
- Answered before61%
- Never answered39%
- 1LimitedNetwork-ASAS213790227,474
- 2SECURED SERVERS LLCAS1943779,187
- 3SECURED SERVERS LLCAS2045447,191
- 4Amazon.com, Inc.AS1650944,501
- 5Cloudflare, Inc.AS1333522,924
- 6M247AS900919,003
- 7Cloudflare, Inc.AS20924214,275
- 8Alibaba (US) Technology Co., Ltd.AS4510212,247
How to use this proxy
Route a request through 47.251.87.199:4145 over SOCKS4. Free proxies are shared and rotate out fast, so test before you rely on it.
curl -x socks4://47.251.87.199:4145 \
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 47.251.87.199:4145
47.251.87.199:4145 is in the live pool right now, and it stays there only for as long as it keeps answering.
Port 4145: SOCKS4, common
Port 4145 is everywhere in free proxy lists, nearly always as SOCKS4. No standards body ever gave it that job. It stuck because everyone copied everyone else, so treat the number as a strong hint rather than a promise.
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 47.251.87.199:4145 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 SOCKS4.
4,258 checks, 207 answered
That is 5% of the time, measured since June 14, 2026. Every one of those results, successes and failures alike, is a connection HProxy opened itself.
It is being re-tested continuously
47.251.87.199:4145 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 47.251.87.199:4145, and nothing it does not.
- First seen
- June 14, 2026
- Last checked
- September 12, 2026
- Next check due
- continuously
- Checks run
- 4,258
- Times it answered
- 207
- Spoke
- SOCKS4
5%
answered 207 of 4,258 checks
Questions about 47.251.87.199:4145
Is 47.251.87.199:4145 a working proxy right now?
Yes. 47.251.87.199:4145 answered HProxy's automated check yesterday 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 47.251.87.199?
It speaks SOCKS4, and our checks grade it elite. The port is 4145. Point your client at 47.251.87.199:4145 over socks4 to route a request through it.
Where is 47.251.87.199 located?
Traffic through it exits from United States, on Alibaba (US) Technology Co., Ltd. (AS45102). That is where the destination site will think your request came from.
How fast is 47.251.87.199:4145?
It answered in 3650ms on the last check. Free public proxies are shared, so real-world speed varies with how many other people are using it at the same moment.
How reliable has 47.251.87.199:4145 been?
Across 82 days of tracking it answered 5% 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 47.251.87.199:4145?
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 Alibaba?
27 other free proxies are live on Alibaba (AS45102) in our pool right now, alongside 47.251.87.199:4145. 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 United States?
Yes, 17,282 free proxies are exiting from United States in our pool right now, answering in 4253ms 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.
47.251.87.199:4145 answers 5% 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
47.251.87.74:13
SOCKS4 · United States · 7% · 3325ms
47.91.65.23:3128
HTTP · Germany · 99% · 158ms
8.219.211.85:80
HTTP · Singapore · 87% · 338ms
47.89.184.18:3128
HTTP · United States · 99% · 474ms
47.91.104.88:3128
HTTP · United Arab Emirates · 93% · 474ms
47.85.37.60:1080
SOCKS4 · United States · 26% · 496ms
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.