Best Proxy Server Software in 2026: 17 Open-Source and Paid Tools Compared

Software roundup · Last reviewed 1 October 2026 · 16 min read

Proxy server software is the program that sits between clients and servers and relays their traffic: a forward proxy for users heading out to the internet, or a reverse proxy in front of your own websites and APIs. This roundup compares 17 proxy servers that are alive and maintained in 2026, most of them open source, checked on each project’s own site on 1 October 2026. It covers forward vs reverse proxies, caching, protocols, authentication, operating systems and licences, gives a minimal config for most tools, and explains when running your own server stops being enough and you need proxy IPs instead.

What a proxy server does

A proxy server accepts a connection from a client, makes its own connection to the destination, and passes the traffic between the two. What it does in the middle depends on the software: it can cache responses, check a password, filter or rewrite content, log requests, spread load across several servers, or terminate TLS.

The first question is which side of the connection the proxy works for. A forward proxy works for clients. Browsers, apps or scripts are configured to use it, and it fetches pages from the internet on their behalf. Offices use forward proxies to cache and control web access; developers use them to route tools through one exit point. A reverse proxy works for servers. Visitors connect to it as if it were the website, and it hands requests to one or more backend servers behind it, usually with TLS, caching and load balancing on the way.

Most proxy server software is built for one of those two jobs and is only passable at the other. HAProxy’s own starter guide states that it is not an explicit HTTP proxy of the kind browsers use to reach the internet; Squid is the reverse, a forward proxy first with a reverse (accelerator) mode added. A third group, debugging proxies such as mitmproxy, sits between one developer’s device and the internet so they can read and change the traffic. There is also a fourth kind, the transparent proxy, which intercepts traffic at the network level without any client configuration; Squid, Tinyproxy and mitmproxy can all run that way.

How to choose proxy server software

Forward vs reverse matters most because the two kinds are configured in opposite directions. A forward proxy needs rules about which clients may use it and where they may go. A reverse proxy needs rules about which hostnames and paths go to which backend. Using a reverse proxy as a forward proxy usually means fighting the software: NGINX’s proxy module passes requests to servers you name and has no CONNECT support for tunnelling HTTPS on behalf of browsers.

Caching saves bandwidth when many users fetch the same things, but it matters much less than it used to. Most web traffic is now HTTPS, and a forward proxy can only cache HTTPS content if it decrypts it, which Squid does with its ssl-bump mode and a certificate installed on every client. Without that, a forward proxy tunnels HTTPS through CONNECT and simply relays the bytes. On the reverse side, caching is still valuable because you control the certificates.

Protocols: nearly every forward proxy here speaks HTTP and tunnels HTTPS. For SOCKS proxies, which carry any TCP connection and, in SOCKS5, UDP too, look at Dante, 3proxy, WinGate or mitmproxy’s socks5 mode. On the reverse side, check HTTP/2 and HTTP/3 support, gRPC for microservices, and plain TCP or UDP load balancing if you proxy databases, game servers or DNS.

Authentication: Squid supports many schemes through helper programs, including basic auth against a password file. Tinyproxy, 3proxy and mitmproxy have simple username and password options, Dante can check logins against the system password file or PAM, and most tools can also restrict access by client IP range.

Operating system and licence close the list. If the server runs Linux, everything here works except the Windows-only WinGate. If it must run Windows, the list shrinks, and NGINX’s own docs call its Windows version a beta. If your company has licence rules, note that Squid, Tinyproxy and Privoxy are GPL, NGINX, Dante and Vinyl Cache are BSD-style, Traefik and mitmproxy are MIT, and Envoy, Caddy, Apache httpd and Apache Traffic Server are Apache 2.0.

Proxy server software compared

Versions and licences from each project’s own site, release page or licence file, checked 1 October 2026. Links in the references.

Open-source forward proxies

These are the tools people usually mean by “open source proxy server”: you install one on a machine, point browsers or scripts at it, and it relays their requests.

Squid

• GPLv2
• Forward + caching
• HTTP, HTTPS, FTP
• Linux, BSD
• 7.7, 24 Aug 2026

Squid is the long-standing open-source caching forward proxy and still the default choice for an office or school web proxy. It listens on port 3128 by default and controls access with ACLs: lists of client addresses, users, destination domains, ports and times, combined into allow and deny rules that are checked in order. Authentication goes through helper programs, from a simple password file to LDAP and Kerberos. The same http_port directive has modes for interception (a transparent proxy), acceleration (reverse proxy) and ssl-bump, which decrypts HTTPS for inspection and caching once clients trust your certificate. Squid can also forward everything to a parent proxy with cache_peer.

Best for: a shared web proxy with caching, per-user logins and detailed rules. The trade-off is a large configuration language and upkeep: Squid’s developers only support the latest stable release, and Windows and macOS builds come from third parties.

http_port 3128
auth_param basic program /usr/lib/squid/basic_ncsa_auth /etc/squid/passwords
auth_param basic children 5
acl office src 192.168.10.0/24
acl auth proxy_auth REQUIRED
http_access deny !auth
http_access allow office auth
http_access deny all

Keep the default Safe_ports and CONNECT rules from the stock squid.conf above these lines. The helper path varies by distribution, and the password file is created with htpasswd.

Tinyproxy

• GPLv2 or later
• Forward, lightweight
• HTTP, HTTPS
• POSIX
• 1.11.3, 7 Mar 2026

Tinyproxy describes itself as a light-weight HTTP/HTTPS proxy daemon for POSIX systems, and its site puts the memory footprint around 2 MB with glibc. It tunnels HTTPS with CONNECT (and ConnectPort limits which ports that may reach), restricts clients with Allow and Deny, supports BasicAuth, filters URLs and domains with regular expressions, and can hand requests to an upstream HTTP, SOCKS4 or SOCKS5 proxy, either for everything or per site. It also has reverse and transparent modes. It does not cache.

Best for: a quick private forward proxy on a small VPS, a Raspberry Pi or a router. No Windows version.

Port 8888
Listen 192.168.10.5
Allow 192.168.10.0/24
BasicAuth alice change-this-password
ConnectPort 443

Privoxy

• GPLv2 or later
• Filtering, no cache
• HTTP, HTTPS
• Windows, macOS, Linux, BSD
• 4.2.0

Privoxy is a non-caching web proxy built around filtering: it rewrites headers, blocks ads and trackers, and changes page content with action and filter files. It listens on 127.0.0.1:8118 by default, which suits one person running it next to the browser, and can forward to a parent HTTP proxy or through SOCKS; the classic use is chaining a browser to Tor. Builds that include HTTPS inspection can filter inside encrypted pages too. Downloads exist for Windows, macOS, Debian, FreeBSD and more.

Best for: privacy filtering for one machine or a home network. It isn’t a caching office proxy and doesn’t try to be.

listen-address 127.0.0.1:8118
forward-socks5t / 127.0.0.1:9050 .

3proxy

• Own licence or Apache 2.0 / GPL / LGPL
• Multi-protocol
• HTTP, SOCKS, FTP, mail
• Windows, Linux, macOS, BSD
• 1.0.0, 22 Aug 2026

3proxy calls itself a tiny free proxy server, and it packs a lot in: an HTTP/1.1 proxy with CONNECT, SOCKS4, 4.5 and 5, FTP, POP3 and SMTP proxies, an SNI-based TLS proxy, TCP and UDP port mapping, and a DNS proxy. It runs natively on Windows as well as Linux, macOS and BSD, which makes it one of the few real answers to “open source proxy server for Windows”. Users, access rules, bandwidth limits and parent proxies are all set in one text file. Version 1.0 arrived in August 2026, with a 0.9.9.x long-term branch still maintained.

Best for: an HTTP and SOCKS5 proxy from one small binary, including on Windows.

nserver 1.1.1.1
users alice:CL:change-this-password
auth strong
allow alice
proxy -p3128
socks -p1080

Dante

• BSD/CMU-type
• SOCKS server
• SOCKS4, SOCKS5
• Linux, Unix-like
• 1.4.4, 15 Dec 2024

Dante, from Inferno Nettverk, is a SOCKS server and client implementing RFC 1928. It does one job, SOCKS, and does it with fine control: separate client rules (who may connect) and socks rules (what they may do, including CONNECT, BIND and UDP associate), authentication by system username and password, PAM, GSSAPI or none, and logging per rule. Commercial support is sold by the authors, but the software is free with full source. Releases are infrequent; 1.4.4 is the current one.

Best for: a dedicated SOCKS5 server on Linux. For HTTP proxying, pair it with Squid or Tinyproxy.

logoutput: syslog
internal: eth0 port = 1080
external: eth0
clientmethod: none
socksmethod: username
user.privileged: root
user.unprivileged: sockd
client pass {
    from: 192.168.10.0/24 to: 0.0.0.0/0
}
socks pass {
    from: 192.168.10.0/24 to: 0.0.0.0/0
    command: connect
}

Open-source reverse proxies and load balancers

These tools sit in front of your own servers. They terminate TLS, route by hostname and path, balance load, and often cache. None of them is meant to be configured in a browser as an internet proxy.

NGINX

• BSD-2-Clause
• Reverse + web server
• HTTP/1.1, HTTP/2, TCP/UDP
• Linux, BSD, macOS
• 1.30.5 / 1.31.6, 15 Sep 2026

NGINX is a web server and reverse proxy in one, which is why it fronts so many sites: it serves static files itself and passes everything else to an application with proxy_pass. It load-balances across upstream groups, caches responses, and proxies raw TCP and UDP through its stream module. HTTP/3 support has existed since 1.25.0 but is still marked experimental and isn’t built by default. nginx.org ships a stable branch (1.30) and a mainline branch (1.31). The Windows build works but is officially a beta, without high performance or UDP.

Best for: the default reverse proxy for a web app, especially when you also serve files.

server {
    listen 80;
    server_name app.example.com;
    location / {
        proxy_pass       http://127.0.0.1:8000;
        proxy_set_header Host      $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

HAProxy

• GPLv2
• Load balancer
• HTTP/1.1, HTTP/2, HTTP/3, TCP
• Linux first
• 3.4.6, 3.4 LTS

HAProxy is a load balancer and reverse proxy for TCP and HTTP, known for staying fast and stable under heavy traffic. It health-checks backends and drops failed ones, supports many balancing algorithms and sticky sessions, terminates TLS, and has supported QUIC and HTTP/3 since version 2.6. Branch 3.4, released in June 2026, is a long-term-support branch maintained until 2031. HAProxy is developed primarily on Linux, and its own guide says plainly that it isn’t a browser-facing forward proxy.

Best for: load balancing many backend servers with health checks and detailed stats.

defaults
    mode http
    timeout connect 5s
    timeout client  30s
    timeout server  30s

frontend www
    bind :80
    default_backend app

backend app
    balance roundrobin
    server app1 10.0.0.11:8080 check
    server app2 10.0.0.12:8080 check

Envoy

• Apache 2.0
• Service proxy
• HTTP/1.1, HTTP/2, HTTP/3, gRPC
• Linux, macOS
• 1.39.1, 27 Aug 2026

Envoy describes itself as an L7 proxy and communication bus for large service-oriented architectures. It is the data plane behind many service meshes and API gateways: dynamic configuration over APIs, service discovery, advanced load balancing, retries and circuit breaking, first-class gRPC, and detailed stats and tracing. Its configuration is verbose YAML, usually generated by a control plane rather than written by hand, so a minimal example here wouldn’t help much. The project recommends its Docker images or static Linux binaries; the apt repository is marked unmaintained.

Best for: microservices, service meshes and Kubernetes gateways. Overkill for one website.

Caddy

• Apache 2.0
• Reverse + web server
• HTTP/1.1, HTTP/2, HTTP/3
• Linux, macOS, Windows
• 2.11.4, 3 Jun 2026

Caddy’s selling point is automatic HTTPS: give it a public hostname and it obtains certificates from Let’s Encrypt or ZeroSSL, renews them, and redirects HTTP to HTTPS without any extra config. HTTP/1.1, HTTP/2 and HTTP/3 are all on by default. It ships as a single static binary for Linux, macOS and Windows, and a reverse proxy can be a two-line Caddyfile or a single caddy reverse-proxy command.

Best for: the quickest route to a correct HTTPS reverse proxy, on any OS.

app.example.com {
    reverse_proxy localhost:8000
}

Traefik

• MIT
• Edge router
• HTTP, TCP, UDP, gRPC
• Linux, Windows, macOS, BSD
• 3.7.13, 4 Sep 2026

Traefik calls itself an open-source application proxy, and its trick is discovery: it watches Docker, Docker Swarm, Kubernetes (Ingress, Gateway API and its own CRDs), Nomad, Consul, ECS and others, and builds routes from labels or resources as containers start and stop, without restarts. It gets Let’s Encrypt certificates through ACME and routes HTTP, TCP and UDP. Configuration lives in container labels or Kubernetes objects rather than one file, so the right snippet depends on your platform. Version 3.7 is current, and 2.11 still gets security fixes.

Best for: Docker and Kubernetes setups where services come and go.

Apache HTTP Server (mod_proxy)

• Apache 2.0
• Reverse and forward
• HTTP, HTTPS, WebSocket, AJP
• Linux, Unix, Windows
• 2.4.68, 8 Jun 2026

Apache httpd’s mod_proxy family turns the web server into a reverse proxy with ProxyPass, a load balancer with mod_proxy_balancer, and even a forward proxy with ProxyRequests On plus mod_proxy_connect for HTTPS tunnels. It is rarely the first choice for a new build, but it is the natural one when Apache already serves your site. The documentation is blunt about the forward mode: don’t enable ProxyRequests until the server is secured, because open proxies are dangerous to your network and the internet.

Best for: adding reverse proxying to an existing Apache installation.

ProxyPass        "/app/" "http://127.0.0.1:8000/"
ProxyPassReverse "/app/" "http://127.0.0.1:8000/"

Vinyl Cache (formerly Varnish Cache)

• BSD-2-Clause
• Caching reverse proxy
• HTTP
• Linux, Unix-like
• 9.1.0, 16 Sep 2026

The open-source project long known as Varnish Cache is changing its name to Vinyl Cache; the rename was announced in 2026, around the project’s 20th anniversary. It is a caching HTTP reverse proxy you put in front of any HTTP server, configured with its own language, VCL, and released every six months. Varnish Software continues a separate distribution under the Varnish Cache name.

Best for: caching heavy, repeatable HTTP traffic for news, media and e-commerce sites.

Apache Traffic Server

• Apache 2.0
• Caching, forward + reverse
• HTTP/1.1, HTTP/2
• Linux, Unix-like
• 10.2.0, 17 Aug 2026

Apache Traffic Server is a fast, extensible caching proxy that works as both a forward and a reverse proxy. The project says it powers large CDNs and content providers. It is built for scale and extended through plugins, which makes it more than most single sites need. Version 10 is the current branch, with 9.2 still getting security releases.

Best for: CDN-style caching at very high volume.

Debugging and inspection proxies

Debugging proxies run on a developer’s machine. Point a browser, phone or app at them, install their certificate, and you can see every request and response in plain text, edit them, replay them, or slow the connection down. Only use them on traffic you own or are allowed to test.

mitmproxy

• MIT
• Intercepting proxy
• HTTP/1-3, WebSocket, TLS
• Windows, macOS, Linux
• 12.2.3, 12 May 2026

mitmproxy is a free and open-source interactive HTTPS proxy with three front ends: mitmproxy in the terminal, mitmweb in the browser, and mitmdump for scripting with Python add-ons. It handles HTTP/1, HTTP/2, HTTP/3 and WebSockets, and runs in regular, transparent, reverse, upstream, SOCKS5, WireGuard and local-capture modes. The default port is 8080. Because it is scriptable, it is also used to rewrite or record traffic automatically in tests.

Best for: free, scriptable inspection of HTTPS traffic.

mitmproxy --listen-port 8080
mitmdump --mode reverse:https://example.com

Charles

• Paid, $50 per licence
• Debugging
• HTTP, HTTPS
• Windows, macOS, Linux
• 5.2.1, 4 Aug 2026

Charles is an HTTP proxy and monitor that runs on your own computer, aimed at web and mobile developers. It offers SSL proxying to read HTTPS, bandwidth throttling to simulate slow connections, breakpoints to pause and edit requests, and one-click repeat. A single-user licence is USD 50, and you can try it for 30 days first.

Best for: a polished GUI for debugging phone and web apps.

Fiddler Everywhere

• Paid subscription
• Debugging
• HTTP/S, HTTP/2, WebSocket, gRPC
• Windows, macOS, Linux
• 8.2.0, 29 Sep 2026

Fiddler Everywhere, from Progress Telerik, captures, inspects, modifies and replays HTTP and HTTPS traffic, and decodes HTTP/2, WebSockets, gRPC, server-sent events, SignalR and Socket.IO. It runs on Windows, macOS and Linux and is sold as a monthly or annual subscription with a 10-day trial. Fiddler Classic still exists as the older Windows-only tool.

Best for: teams that want a supported commercial debugger on every desktop OS.

Proxy servers for Windows, Linux and macOS

Linux is home ground for almost everything here. For an open-source proxy server on Linux, the usual picks are Squid (forward, caching), Tinyproxy (forward, light), Dante (SOCKS5), and NGINX, HAProxy or Caddy (reverse). All are packaged by the major distributions.

Windows has fewer native options. For an open-source proxy server on Windows, 3proxy is the most complete forward proxy, with HTTP and SOCKS5 in one binary. Privoxy has a Windows installer for filtering, Caddy and Traefik ship Windows builds for reverse proxying, and mitmproxy covers debugging. NGINX runs on Windows as a beta. Squid on Windows comes only from third-party builds.

WinGate

• Paid; free edition for 10 users
• Gateway + caching
• HTTP, SOCKS, mail
• Windows only
• 9.4.11, 23 Sep 2026

WinGate describes itself as a caching HTTP proxy, SOCKS server, multi-protocol proxy, email server and internet gateway for Windows. It can inspect HTTPS, scan for malware with an optional Kaspersky module, and control and log user access through a Windows GUI. The free edition covers up to 10 users, and paid editions come with a 30-day trial. It is the most complete commercial Windows proxy gateway we could verify.

Best for: a Windows shop that wants a GUI gateway instead of a Linux box.

Left out: CCProxy. Its download page still offers version 8.0 from September 2018 and lists nothing newer than Windows 10, so we treated it as unmaintained.

macOS is best treated as a development platform. mitmproxy, Charles, Fiddler Everywhere, Caddy and Traefik all run natively, and Squid, Tinyproxy, Privoxy and NGINX install through package managers, but a production proxy normally lives on a Linux server.

Proxifier is a proxy client, not a server

Proxifier often shows up in lists of proxy software, but it does the opposite job. It is a client for Windows and macOS that forces applications without their own proxy settings to go through a proxy you already have, using SOCKS4, SOCKS4A, SOCKS5, HTTPS or HTTP. Rules pick which apps or hostnames go through which proxy, and it can chain several proxies. Windows version 4.14 and macOS version 3.15 are current; licences are a one-time purchase after a 31-day trial.

Use Proxifier with any server in this roundup, or with a proxy provider. Our Proxifier setup guide walks through adding a proxy and writing rules.

Don’t run an open proxy

A forward proxy that accepts connections from anyone on the internet is an open proxy. Automated scanners look for them, and they get used to send spam, attack sites and hide abuse behind your server’s IP address, which then ends up on blocklists. Apache’s mod_proxy documentation warns against enabling forward proxying before the server is secured, and the same applies to every forward proxy here.

• Bind to the right interface. Listen on a private address or localhost unless the proxy must be public (Squid’s http_port with an address, Tinyproxy’s Listen, Dante’s internal).
• Allow known clients only. Restrict by source IP range, and end your rules with a deny for everyone else.
• Require a login when clients connect from changing addresses: Squid auth helpers, Tinyproxy BasicAuth, 3proxy users, Dante username or PAM.
• Limit tunnels. Allow CONNECT only to port 443 (Squid’s default SSL_ports rule, Tinyproxy’s ConnectPort) so the proxy can’t be used to reach mail servers or other services.
• Firewall and log. Close the proxy port to the world if a VPN or an allowlist can do the job, and keep access logs so you can see who is using it.
• Update. Proxies face the network and get security fixes often; several releases in the table above were security releases.

Running your own proxy server vs buying proxy IPs

Every tool in this roundup relays traffic from the machine it runs on. However you configure it, websites see that machine’s IP address. Install Squid on a cloud VPS and you usually have one datacenter IP in one city; install it at home and you have your home IP, which your provider may even share with other customers. Proxy server software can’t give you a different country, a residential or mobile address, or a new IP every request, because those come from the network, not the program.

Run your own proxy server when you need control: caching an office’s traffic, filtering, logging, one fixed exit for a partner’s allowlist, or a reverse proxy for your own site. Buy proxy IPs when the job needs many addresses or specific ones: checking search results or prices in other countries, verifying ads as local users see them, testing geo-targeted content, or collecting public data at a scale where one IP would be rate-limited.

That second job is what ProxyEmpire sells. Rotating residential proxies give you 30M+ IPs in 179 countries and territories, and rotating mobile proxies give you 4M+ carrier IPs in 174 countries. Both let you target by country, region, city, ZIP, ISP or carrier, ASN and OS at no extra charge, and both offer rotating or sticky sessions. Rotating datacenter proxies start from $0.35/GB. Uptime is 99.9%, shown on the public status page, and support is 24/7 from real people.

Using both: point your server at a provider

The two approaches combine well. Keep your own proxy for control and logging, and make a provider its upstream, so your clients still connect to your server but traffic leaves from residential or mobile IPs. This is proxy chaining, and most forward proxies here support it. ProxyEmpire’s residential and mobile gateway is v2.proxyempire.io on port 5000, with username and password authentication (there is no IP allowlisting), so the upstream settings need your credentials.

# Squid (squid.conf)
cache_peer v2.proxyempire.io parent 5000 0 no-query default login=USERNAME:PASSWORD
never_direct allow all

# Tinyproxy (tinyproxy.conf)
upstream http USERNAME:PASSWORD@v2.proxyempire.io:5000

# mitmproxy
mitmdump --mode upstream:http://v2.proxyempire.io:5000 --set upstream_auth=USERNAME:PASSWORD

Two limits to plan around: only ports 80 and 443 are open by default and there is no UDP, so chain web traffic, not mail or games. Financial, government, crypto, bank and payment sites are blocked on all ProxyEmpire proxy types unless an account passes KYC and a use-case review. The $1.97 trial includes 100 MB of residential and 50 MB of mobile traffic, which is enough to test a chain end to end.

Proxy server FAQ

References

1. Squid — versions and http_port directive. squid-cache.org/Versions · http_port
2. Squid — cache_peer and never_direct directives. cache_peer · never_direct
3. Squid wiki — NCSA basic authentication example. wiki.squid-cache.org/ConfigExamples/Authenticate/Ncsa
4. Tinyproxy — project site and configuration reference. tinyproxy.github.io
5. Privoxy — user manual, main configuration. privoxy.org/user-manual/config.html
6. 3proxy — project repository and how-to. github.com/3proxy/3proxy · 3proxy.org/doc/howtoe.html
7. Inferno Nettverk — Dante and the sockd.conf manual. inet.no/dante · sockd.conf(5)
8. NGINX — proxy module and nginx for Windows. ngx_http_proxy_module · nginx for Windows
9. HAProxy — starter guide (3.4) and project site. docs.haproxy.org/3.4/intro.html · haproxy.org
10. Envoy — what is Envoy. envoyproxy.io/docs
11. Caddy — reverse proxy quick-start and automatic HTTPS. reverse proxy quick-start · automatic HTTPS
12. Traefik — documentation overview. doc.traefik.io/traefik
13. Apache HTTP Server — mod_proxy. httpd.apache.org/docs/2.4/mod/mod_proxy.html
14. Vinyl Cache — releases. vinyl-cache.org/releases
15. Apache Traffic Server — project site. trafficserver.apache.org
16. mitmproxy — proxy modes and options. modes · options
17. Charles — version history. charlesproxy.com/documentation/version-history
18. Progress Telerik — Fiddler Everywhere release history. telerik.com/support/whats-new/fiddler-everywhere
19. WinGate — official site. wingate.com
20. Proxifier — documentation for Windows v4. proxifier.com/docs/win-v4