UnFX Proxy Checker is a free desktop proxy checker, built mainly for Windows and published on GitHub by Open Proxy Space under the MIT license. Its last release, version 1.7.2, came out on September 17, 2022, and nothing has followed. On October 23, 2026, the site its README sends you to answered with an error. Two of the seven judges it uses to grade anonymity still answered as designed.
This page sets out what the tool did, what has changed since 2022, and what still works. It ends with the free checker we maintain for the same job. We did not download or run UnFX: everything about its behavior comes from its own source code on GitHub.
What UnFX Proxy Checker does
You paste a list, and the tool tests each proxy for HTTP, HTTPS, SOCKS4 and SOCKS5. Its defaults run 350 checks at a time, wait 15 seconds for each and retry nothing. It sorts and filters the results, and its own description promises "huge features and beautiful design".
To grade anonymity, a checker sends a request through the proxy to a judge. A judge is a page that echoes back what reached it: the address, and headers such as Via or X-Forwarded-For. If the echo shows your own address, the proxy leaks it. UnFX ships with nine judges, all run by other people.
It was popular. GitHub counts 209,786 downloads of its installers and portable files across eleven releases:
A download counter counts files fetched. It cannot tell how many copies still run.
What has changed since 2022
The repository's last commit is from September 18, 2022, a fix for the Linux build. The project was never archived. It simply stopped.
Version 1.7.2 is built on Electron 20, which carries Chromium 104. Electron supports the three newest major versions only. Electron 23 shipped on February 6, 2023, so Electron 20 left support that day; its last update came two days later. Electron reached version 45 on October 21, 2026.
The README points to openproxy.space for the full description and documentation. On October 23, 2026, that site answered with error 521 from Cloudflare, which means the server behind it is down. The Internet Archive shows the same error on every copy since March 27, 2025. Its last working copy is from November 25, 2024.
Two more outside addresses sit in the code. One is a stats address on api.openproxy.space, which answered the same error. The update check asks for releases under the repository's earlier owner name, which GitHub now answers with a redirect.
Do its judges still answer?
We asked each of the nine default judges once, from a server, on October 23, 2026. We sent nothing through any proxy:
The move to https matters more than it looks. Through an HTTP proxy, an https judge is reached inside an encrypted tunnel, where the proxy cannot add headers. Such a judge cannot show a leak, so every proxy looks clean there. The two address services cannot grade headers at all.
That leaves two working judges, both run by strangers who see every request you send them. You can add judges in UnFX's settings, but you must find ones that still run.
What its users asked for
The issue tracker shows what people wanted next. In 2020, users asked for a macOS or Linux version and for a web version. In 2021, one wrote "Don't give up on this project please." In 2022, another asked for a command-line version. An "Ip lookup error" report from June 2023 is still open.
Version 1.7.2 brought back a Linux build, which early 2019 versions had offered. The rest never came.
A free checker that is maintained: the HProxy app
We make a free proxy checker, and we sell residential proxies, so read this part with that in mind. Our app is free and open source, with its code public on GitHub. It runs on Windows 10 and 11, on macOS for Apple silicon and Intel, and on Linux as an AppImage or a .deb. It is also listed in the Microsoft Store and on Google Play.
- It checks from your own connection. A proxy locked to your IP address can only be tested from that address, so this matters for paid proxies.
- Its judges run on our own domain. The first is our own reflector, which returns the address it saw and every header, for a full grade. Cloudflare's trace page on our domain is the fallback.
- It needs the right answer, not just any answer. Each check sends a one-time code, and a proxy counts only when the judge returns that code.
- It checks its own updates. There is also a command-line tool and an MCP server for AI assistants.
Get it on our proxy checker page.
Or check a list online
If you would rather install nothing, our online proxy checker runs in the browser. It takes up to 100,000 lines a run, and 300,000 a day from one address, with no account. It tries HTTP, HTTPS, SOCKS4 and SOCKS5 on every line. It cannot reach a proxy locked to your own IP address; the app does that.
To read the results, our guides on checking if a proxy works and on anonymity levels explain each column.
Where HProxy fits
The checkers are free. What we sell is residential proxies: Residential Lite costs $0.50/GB for one GB, falling to $0.44/GB at 2,000 GB+, and the balance does not expire. If a free list keeps failing your checks, a paid pool is the next step, and you can test it with the same tools.
What we could not find out
We did not run UnFX, so we cannot say how its current build behaves on a given machine. Its documentation site is down, and we did not read the archive's copies of it. Our judge check is one request from one server at one moment, and judges can come back or go away. GitHub's counters count downloads, never people.
Sources
- UnFX Proxy Checker's repository on GitHub (openproxyspace/unfx-proxy-checker): its description, README, package.json (Electron ^20.1.4), src/constants (default settings, judges, stats and update addresses) and issues #23, #39, #42, #47, #51 and #54, read October 23, 2026.
- GitHub's release records for the repository, with download counters, read October 23, 2026.
- Electron's release data (releases.electronjs.org) and its version support policy, read October 23, 2026.
- The Internet Archive's index of openproxy.space, read October 23, 2026.
- Our own checks from a server on October 23, 2026: the nine default judges, openproxy.space and its stats address.
- HProxy's app and checker code: the app's judges (hproxy-probe), the online checker's limits and its one-time code.
