Proxy glossary: 59 proxy terms explained

Ad verification is checking that online adverts appear where, when and how they were bought: in the right country, on the right sites and with the right landing page. Because ads are targeted by location and device, checks are run through IPs in the markets being tested.

On ZenProxy: Residential and mobile IPs with country targeting let you follow an ad and its redirect chain as a local visitor sees it, with one sticky line per journey.

Proxies for ad verification → Related: Geo-targeting, Sticky session, Mobile proxy

An anonymous proxy hides your own IP address from the website but still announces that a proxy is in use, usually through headers such as Via or X-Forwarded-For. It sits between a transparent proxy, which passes your IP on, and an elite proxy, which reveals neither.

Related: Transparent proxy, Elite proxy, Exit IP

An anti-detect browser runs many separate browser profiles, each with its own cookies, storage and browser settings, so that accounts managed side by side stay apart. Agencies and teams use them to run their own or their clients’ accounts, giving each profile its own proxy; each platform’s own rules still apply.

On ZenProxy: ZenProxy has step-by-step setup guides for AdsPower, Multilogin, GoLogin, Dolphin Anty and Incogniton. Give each profile its own sticky line or static ISP IP.

Anti-detect browser setup guides → Related: Browser fingerprint, Sticky session, Static ISP proxy

An ASN is the number that identifies one network on the internet, such as a national broadband provider, a mobile carrier or a hosting company. Every public IP address is announced by an ASN, which is why IP lookup tools can tell whether an address belongs to a home ISP, a carrier or a data centre.

On ZenProxy: ZenProxy country pages list major local ISPs with their ASNs and ready-to-copy -asn- examples for Residential Premium.

Locations and ISPs by country → Related: ASN targeting, Carrier targeting, IP reputation

ASN targeting means asking a proxy network for an exit IP from one specific network, for example one broadband provider in one country. It is used to test or verify what customers of a particular ISP see, such as local ads, prices or search results.

On ZenProxy: On Residential Premium, add the network’s ASN to your proxy username next to the country; on Mobile, choose the carrier by its ASN in the proxy generator.

ASN targeting guide → Related: ASN (autonomous system number), Carrier targeting, Geo-targeting

A backconnect proxy is a single hostname and port (a gateway) that forwards each connection to an IP from a large pool, instead of giving you a fixed list of addresses. Targeting and session options are usually set in the username, so one line can reach many IPs and countries.

On ZenProxy: Residential, Mobile, Unlimited Residential and Rotating Datacenter plans work this way: copy a line from the proxy generator and the gateway picks the IP.

Rotating Datacenter: one endpoint → Related: Rotating proxy, IP pool, Sticky session

A browser fingerprint is the set of details a website can read from a browser, such as the user agent, screen size, time zone, language, fonts and graphics features, which together can recognise a returning device without cookies. A proxy changes the IP address only; the fingerprint comes from the browser.

On ZenProxy: For account work, pair each ZenProxy line with its own browser profile and set the profile’s time zone and language to match the proxy’s country.

Browser and anti-detect setup guides → Related: Anti-detect browser, User agent, WebRTC leak

A CAPTCHA is a test a website shows to tell people from automated traffic, such as ticking a box, picking images or a background check the visitor never sees. Sites show more of them to IPs, browsers or request rates they don’t trust, and they are part of the site’s own access rules.

On ZenProxy: If a site challenges datacenter traffic, residential or mobile IPs, which come from consumer networks, usually suit it better; slowing your request rate helps on any IP type.

Compare proxy types → Related: Rate limiting, IP reputation, Residential proxy

Carrier targeting means choosing which mobile network an exit IP comes from, for example one operator in one country. It matters for testing mobile-only offers, app behaviour and ads that differ by operator.

On ZenProxy: ZenProxy Mobile lets you pick the country and, optionally, the carrier by its ASN in the proxy generator, over HTTP(S) or SOCKS5.

Mobile proxies → Related: Mobile proxy, ASN (autonomous system number), ASN targeting

City targeting asks a proxy network for an exit IP located in a particular city, so a website sees a local visitor. Which cities have IPs online changes over time on residential networks, because the IPs belong to real devices.

On ZenProxy: Residential Premium supports city targeting, Residential Lite supports US cities (with their state), and Private ISP has dedicated New York and Los Angeles pools.

Proxy locations → Related: Geo-targeting, State targeting, Country targeting

Concurrency, often called threads, is the number of connections you run through a proxy at the same time. Some providers cap it per plan; more threads finish a job faster but also send more traffic to each target at once.

On ZenProxy: ZenProxy per-GB plans charge for data rather than connections, IPv6 plans have no cap on connections at once, and Unlimited Residential is priced by the speed you choose.

Unlimited Residential → Related: Unlimited bandwidth proxy, Rate limiting, IPv6 proxy

CONNECT is the HTTP request a client sends to a proxy to open a tunnel to another host, which is how an HTTP proxy carries https:// traffic. Once the tunnel is open the proxy passes encrypted bytes both ways and cannot read the page.

On ZenProxy: ZenProxy HTTP(S) lines carry https:// sites through a CONNECT tunnel, so the traffic stays encrypted end to end between your app and the site.

SOCKS5 or HTTP: which to use → Related: HTTP(S) proxy, SOCKS5

Country targeting asks a proxy network for an exit IP in a chosen country, so a website serves the local version of its pages, prices and results. Countries are identified by two-letter ISO codes: the United Kingdom is GB, not UK.

On ZenProxy: Residential Lite covers 200+ countries; every residential and mobile plan supports country targeting in the proxy generator, and static IP lists are sold per country.

Every proxy location → Related: Geo-targeting, State targeting, City targeting

A datacenter proxy uses an IP address owned by a hosting or cloud company rather than a home or mobile provider. Datacenter IPs are usually the fastest and cheapest type of proxy, and they work best on sites that don’t restrict traffic from hosting networks.

On ZenProxy: Static Datacenter gives you a dedicated IP list in the country you choose, from 100 IPs; Rotating Datacenter gives one endpoint with a new IP on each new connection and unlimited data, from US or European IPs.

Static datacenter proxies → Related: Residential proxy, ISP proxy, Rotating proxy

A dedicated proxy is an IP address that only one customer uses for the length of the plan, so no one else’s traffic shapes how websites see it. It costs more than a shared proxy and suits accounts and allow-lists that need a known, clean address.

On ZenProxy: Private ISP IPs are dedicated to you, registered to internet providers, in 8 countries plus New York and Los Angeles pools, and stay yours when you renew.

Private ISP proxies → Related: Shared proxy, Static ISP proxy, Subnet

A DNS leak happens when your device looks up a website’s address through your own network’s DNS resolver instead of through the proxy, so your provider (and sometimes the site) can see which domains you visit. Resolving names at the proxy closes it.

On ZenProxy: With ZenProxy SOCKS5 lines, use socks5h:// in curl and Python so DNS lookups happen at the proxy’s exit.

socks5:// or socks5h:// → Related: socks5h, SOCKS5, WebRTC leak

An elite proxy hides your IP address and does not add headers that reveal a proxy is in use, so to the website the request looks like it came straight from the exit IP. It is the highest of the three classic anonymity levels, above anonymous and transparent proxies.

Related: Anonymous proxy, Transparent proxy, Exit IP

The exit IP is the address a website sees when your traffic comes through a proxy: the last hop before the site. Its country, network type and history decide how the site treats you, so it is the first thing to check when a proxy behaves unexpectedly.

On ZenProxy: Paste any ZenProxy HTTP line into the free proxy checker to see its exit IP, country, city, network and response time.

Free proxy checker → Related: IP geolocation, IP reputation, IP pool

A forward proxy sits in front of clients: your app sends its requests to the proxy, and the proxy fetches the page and returns it, so websites see the proxy’s IP. Residential, ISP, mobile and datacenter proxies are all forward proxies.

On ZenProxy: Every ZenProxy product is a forward proxy you set in an app, a browser profile or code with one line.

Setup guides for the tools you use → Related: Reverse proxy, Proxy server, VPN

Geo-blocking is when a website changes or limits what it shows according to the visitor’s country, judged from the IP address. Businesses meet it when testing their own localised sites, checking regional prices or verifying ads in other markets.

On ZenProxy: Pick the country in the proxy generator to load a site as local visitors see it; the site’s own terms and any licensing rules still apply.

Proxies for QA and localisation → Related: Geo-targeting, IP geolocation, Country targeting

Geo-targeting is choosing where your proxy’s exit IP is located, by country and on some networks by state, city or network (ASN). It lets you see search results, prices and ads exactly as people in that place see them.

On ZenProxy: ZenProxy supports country targeting on every residential and mobile plan, US state and city on Residential Lite, and region, city and ASN on Residential Premium.

Targeting by country, city and ASN → Related: Country targeting, State targeting, City targeting, ASN targeting

A headless browser is a real browser engine, such as Chromium, run without a window and controlled by code, for testing and automated page loads. Tools such as Playwright, Puppeteer and Selenium drive one, and each takes a proxy setting when it starts the browser.

On ZenProxy: ZenProxy has setup guides for Playwright, Puppeteer, Selenium and Playwright MCP, with one sticky line per browser context.

Playwright proxy setup → Related: Browser fingerprint, Sticky session, Web scraping

An HTTP proxy understands web requests: it fetches http:// pages for you and opens a CONNECT tunnel for https:// sites, so encrypted traffic passes through unread. “HTTPS proxy” in proxy listings usually means an HTTP proxy that carries HTTPS this way, and every browser and HTTP library supports it.

On ZenProxy: Every ZenProxy product works over HTTP and HTTPS with a username and password, and all except Private ISP also offer SOCKS5.

SOCKS5 or HTTP: which to use → Related: CONNECT method, SOCKS5, Username and password authentication

IP allow-listing lets you use a proxy without a username and password by registering the public IP addresses you connect from. It suits apps and system settings that can’t send proxy credentials, such as Android’s Wi-Fi proxy or Chrome with SOCKS5.

On ZenProxy: ZenProxy customers save their IPs on the Access & API page; login by IP switches on plan by plan, and username and password works on every plan.

Login by IP on Android → Related: Username and password authentication, SOCKS5

IP geolocation is estimating where an IP address is from databases that map address ranges to countries, regions and cities. The country is usually right; the city can show a provider’s hub instead, and different databases sometimes disagree.

On ZenProxy: The free ZenProxy IP lookup shows the location, network and time zone that IP data reports for any address.

Free IP lookup → Related: Exit IP, Geo-targeting, ASN (autonomous system number)

An IP pool is the set of addresses a proxy network can hand out for a product, location or tier. A rotating gateway draws a fresh IP from the pool for each new connection, so the pool’s spread across networks and locations decides what you get.

On ZenProxy: Residential Premium is a separate pool built for strict sites; Residential Lite is the budget pool for volume.

Residential Premium → Related: Backconnect proxy, Rotating proxy, Exit IP

IP reputation is how trustworthy a website or security service judges an IP address, based on its network type (home, mobile or hosting), its past behaviour and blocklists. A low-reputation IP sees more challenges and blocks, whatever the proxy protocol.

On ZenProxy: For strict anti-bot systems, logins and checkouts, ZenProxy sells Residential Premium; check any exit’s network with the free IP lookup.

Residential Premium → Related: Exit IP, CAPTCHA, Residential proxy

IPv4 is the original internet address format: 32-bit addresses written as four numbers, such as 203.0.113.10, giving about 4.3 billion addresses in total. Almost every website accepts IPv4, and because the addresses are scarce, IPv4 proxies generally cost more per address than IPv6.

Related: IPv6, IPv6 proxy, Subnet

IPv6 is the newer internet address format: 128-bit addresses written in hexadecimal groups, such as 2001:db8::1, with an address space vastly larger than IPv4. A website can only be reached over IPv6 if its domain has an IPv6 (AAAA) record.

On ZenProxy: Check a site with dig AAAA example.com +short: if an address comes back, the site accepts IPv6 and suits ZenProxy IPv6 plans.

IPv6 proxies → Related: IPv4, IPv6 proxy

An IPv6 proxy sends your requests to websites from IPv6 addresses, usually drawn from very large address ranges. You still connect to the proxy as usual; it reaches the site over IPv6, which suits highly parallel work on IPv6-ready sites.

On ZenProxy: ZenProxy IPv6 plans come with unlimited data, priced by time, over HTTP(S) and SOCKS5. They work on sites that accept IPv6.

IPv6 proxies → Related: IPv6, Concurrency (threads), Datacenter proxy

An ISP proxy is a static IP registered to an internet service provider but hosted on servers, so it combines an ISP’s network identity with datacenter speed and stability. The address stays the same for the whole plan, which suits long sessions and accounts.

On ZenProxy: ZenProxy sells Shared ISP (budget static IPs shared with other users, currently in the United States) and Private ISP (dedicated IPs registered to internet providers, in 8 countries).

Shared ISP proxies → Related: Static ISP proxy, Dedicated proxy, Shared proxy

Keep-alive is when an HTTP client keeps a connection open and sends several requests over it instead of opening a new one each time. Through a rotating proxy, requests on one open connection share the same exit IP.

On ZenProxy: ZenProxy rotating lines give a new IP for each new connection: open a new connection per request, or turn keep-alive off, to get a new IP every time.

Rotating vs sticky proxies → Related: Rotating proxy, Sticky session, Backconnect proxy

A mobile proxy routes traffic through IPs from mobile carriers’ 4G and 5G networks. Carriers place many real phones behind each IP, so websites are cautious about blocking them, and several requests can share one IP even when rotating.

On ZenProxy: ZenProxy Mobile gives real carrier IPs with country and carrier (ASN) targeting, rotating or sticky, over HTTP(S) and SOCKS5, billed per GB with data valid for 180 days.

Mobile proxies → Related: Carrier targeting, Residential proxy, IP reputation

Per-GB pricing charges for the data that passes through the proxy, both requests and responses, rather than for IPs or time. It suits rotating residential and mobile proxies, where you use many IPs, and makes light or occasional use cheap.

On ZenProxy: Residential Lite, Residential Premium and Mobile are sold per GB from 1 GB, and the rate drops as you buy more; Residential Lite is pay-once with no subscription, and Residential Lite and Mobile data lasts 180 days.

Residential proxy prices per GB → Related: Unlimited bandwidth proxy, Residential proxy, Mobile proxy

A proxy chain sends traffic through two or more proxies in a row, so each hop only sees the one before it. It adds latency and more points that can fail, and the website still sees only the last proxy’s IP.

Related: Exit IP, Forward proxy, Proxy server

A proxy line is the text that holds everything an app needs to connect: hostname, port, username and password. The two common formats are hostname:port:username:password for apps with separate fields and protocol://username:password@hostname:port for code and URL fields.

On ZenProxy: The ZenProxy proxy generator writes lines in either format, for HTTP or SOCKS5, rotating or sticky, and up to 1,000 sticky lines per batch (generate again for more).

How to get a proxy line → Related: Username and password authentication, Sticky session, SOCKS5

A proxy server is an intermediary that forwards your requests to websites and returns the answers, so sites see the proxy’s IP address instead of yours. Proxies are set per app, per browser profile or in code, and are grouped by where their IPs come from: homes, mobile carriers, ISPs or data centers.

On ZenProxy: ZenProxy (zenproxy.io), operated by Zentrix Data in Dubai, UAE, sells residential, mobile, ISP, datacenter and IPv6 proxies with instant delivery, HTTP(S) on every product and payment by card or crypto.

ZenProxy plans and pricing → Related: Forward proxy, Residential proxy, Datacenter proxy

Rate limiting is a website capping how many requests one visitor, usually one IP address, can make in a period, often answering with HTTP 429 Too Many Requests when the cap is passed. It protects the site’s servers, so a well-behaved job keeps its request rate reasonable and backs off when asked.

On ZenProxy: ZenProxy rotating lines spread independent requests across many IPs, and sticky lines keep one visitor on one IP; either way, pace your job to the site.

Which session type for which job → Related: CAPTCHA, Rotating proxy, Concurrency (threads)

A residential proxy routes your traffic through an IP address that an internet provider assigned to a real home connection. Websites see an ordinary household visitor, which makes residential IPs the standard choice for sites that restrict datacenter traffic.

On ZenProxy: Residential Lite covers 200+ countries from 1 GB with US state and city targeting; Residential Premium is a separate pool for strict sites with region, city and ASN targeting. Both run rotating or sticky over HTTP(S) and SOCKS5.

Residential proxies → Related: Mobile proxy, ISP proxy, Datacenter proxy

A reverse proxy sits in front of websites rather than users: it receives visitors’ requests and passes them to the site’s own servers, handling caching, TLS and load balancing. CDNs and load balancers are reverse proxies; the proxies you buy to browse or collect data are forward proxies.

Related: Forward proxy, Proxy server

A rotating proxy gives you a different exit IP from its pool for each new connection, without you managing a list of addresses. It suits independent requests such as listings and search results; for logins and multi-step flows, a sticky session keeps one IP instead.

On ZenProxy: Every ZenProxy residential and mobile plan can rotate, and Rotating Datacenter gives a fresh datacenter IP on each new connection with unlimited data.

Rotating vs sticky proxies → Related: Sticky session, Keep-alive, Backconnect proxy

A SERP is the page of results a search engine shows for a query. Results change with the searcher’s country, city, language and device, so rank-tracking tools check them through IPs in each market they report on.

On ZenProxy: ZenProxy residential lines target the country, and on supported plans the state or city, so you see results as local searchers do, one query per rotating IP.

Proxies for SERP tracking → Related: Geo-targeting, Rotating proxy, Rate limiting

Session length is how long a sticky proxy session keeps the same exit IP before it may change. Longer sessions suit multi-step flows; shorter ones recover faster if a residential device goes offline.

On ZenProxy: Choose a Sticky Duration in the ZenProxy proxy generator: from 1 minute up to 24 hours, depending on the plan.

How sticky sessions work → Related: Sticky session, Rotating proxy

A shared proxy is an IP address that several customers can use at the same time. It costs less than a dedicated proxy, but a website may already have seen traffic from other users on that address.

On ZenProxy: ZenProxy Shared ISP is a fixed list of static ISP IPs for the whole plan at a budget price per IP, with 30-day, 7-day and 1-day plans.

Shared ISP proxies → Related: Dedicated proxy, ISP proxy

SOCKS5 is a proxy protocol that passes along any TCP connection your app opens, so it also suits tools that don’t speak HTTP. It adds no encryption of its own, but HTTPS sites stay encrypted through it, and it supports username and password login.

On ZenProxy: Every ZenProxy product except Private ISP supports SOCKS5 with a username and password: set Protocol to SOCKS5 in the proxy generator.

SOCKS5 proxies → Related: socks5h, HTTP(S) proxy, DNS leak

socks5h:// is the form of a SOCKS5 proxy address that sends the hostname to the proxy and lets the proxy look it up, instead of resolving it on your own machine. Supported in tools such as curl and Python requests, it keeps DNS lookups at the exit and avoids DNS leaks.

On ZenProxy: ZenProxy’s generator writes socks5://; in curl and Python, change the scheme to socks5h:// and keep the rest of the line.

socks5:// or socks5h:// → Related: SOCKS5, DNS leak

State targeting asks a proxy network for an exit IP in a particular state, province or region of a country. It matters where prices, taxes, delivery and search results differ by region.

On ZenProxy: Residential Premium supports region targeting, and Residential Lite supports US states and Canadian provinces.

Proxy locations → Related: Geo-targeting, City targeting, Country targeting

A static ISP proxy is an ISP-registered IP address that stays the same for your whole plan, so websites see the same address every visit. It is the usual choice for accounts you return to for weeks and for allow-lists that need a known IP.

On ZenProxy: ZenProxy Private ISP IPs are dedicated, priced per IP for 30 days and kept when you renew, with pool types Retail+, Retail, Events and General; Shared ISP is the budget option.

Private ISP proxies → Related: ISP proxy, Dedicated proxy, Tier-1 network

A static residential proxy is a fixed IP that websites read as an internet provider’s address rather than a hosting company’s, and that stays the same for the whole plan. In practice the name usually means the same thing as an ISP proxy.

On ZenProxy: ZenProxy Shared ISP and Private ISP are static residential-style IPs: the same addresses for the whole plan, registered to internet providers.

Private ISP proxies → Related: ISP proxy, Static ISP proxy, Residential proxy

A sticky session keeps the same exit IP across many connections for a set time, usually by carrying a session ID in the proxy username. It is what logins, carts and multi-page journeys need, because the site expects one visitor on one address.

On ZenProxy: Set Proxy Type to Sticky in the ZenProxy proxy generator, pick a duration and make up to 1,000 lines per batch (generate again for more); each line is its own session with its own IP.

Rotating vs sticky proxies → Related: Session length, Rotating proxy, Proxy line format

A subnet is a block of neighbouring IP addresses written with a prefix length: a /24 is 256 addresses that share their first three numbers. Websites sometimes judge or limit a whole subnet at once, so spreading IPs across subnets, or owning a full one, changes how they are treated.

On ZenProxy: A dedicated /24 subnet of Private ISP IPs, 256 addresses used only by you, can be quoted for some Private ISP locations and pool types by the ZenProxy sales team, rather than bought in the checkout.

Contact sales for a subnet → Related: Dedicated proxy, Static ISP proxy, IPv4

A Tier-1 network is one of the large carriers at the top of the internet that can reach every other network without buying transit from anyone. Some proxy sellers use “Tier-1” loosely as a marketing word for a large, well-known network; it says nothing about whether the IPs are residential or dedicated.

Related: ASN (autonomous system number), Static ISP proxy

A transparent proxy forwards requests without hiding who you are: it passes your real IP to the website, typically in an X-Forwarded-For header. Networks use them for caching and filtering; they give no privacy.

Related: Anonymous proxy, Elite proxy, Reverse proxy

An unlimited bandwidth proxy is priced by time, and often by speed, instead of by data, so heavy, round-the-clock jobs cost the same however much they move. Throughput is then limited by the connection speed rather than a data allowance.

On ZenProxy: Unlimited Residential offers 9 speeds from 200 Mbps to 1 Gbps, rotating or sticky. Rotating Datacenter and IPv6 plans also include unlimited data, and IPv6 has no cap on connections at once.

Unlimited residential proxies → Related: Per-GB pricing, Concurrency (threads), Residential proxy

The user agent is the header in which a browser or HTTP client names itself and its version, such as a Chrome build on Windows. Sites use it to serve the right page and as one part of a browser fingerprint; a proxy doesn’t change it.

Related: Browser fingerprint, Headless browser

Username and password authentication is the standard way to log in to a paid proxy: the credentials travel with each connection, so the proxy works from any network. A proxy answers 407 Proxy Authentication Required when they are missing or wrong.

On ZenProxy: Every ZenProxy line comes with a username and password, and on gateway plans the username also carries the targeting and session options you set in the proxy generator.

Fix 407 and other proxy errors → Related: IP allow-listing, Proxy line format, HTTP(S) proxy

A VPN sends all the traffic from a device through an encrypted tunnel to one server, so every app shares the VPN server’s IP. A proxy works per app, per browser profile or per request, which lets you run many IPs and locations side by side.

On ZenProxy: ZenProxy sells proxies rather than a VPN, so each tool, profile or thread can use its own IP and country.

What is my IP? → Related: Proxy server, Forward proxy

A WebRTC leak is when a browser’s real-time communication feature reveals your real IP address to a website even though the page loaded through a proxy. It happens because WebRTC can open connections outside the proxy settings.

On ZenProxy: Check your browser’s WebRTC setting and use a separate browser profile for each ZenProxy line, then confirm the IP on the free What is my IP page.

What is my IP? → Related: DNS leak, Browser fingerprint, Anti-detect browser

Web scraping is collecting public information from websites automatically, such as prices, listings, reviews or search results, with code or tools that load pages and extract the data. Responsible scraping keeps to public pages, paces requests and respects each site’s terms.

On ZenProxy: ZenProxy has setup guides for Python, Scrapy, Playwright, Crawlee and more, with rotating lines for independent pages and sticky lines for multi-step flows.

Proxies for web scraping → Related: Rotating proxy, Rate limiting, Headless browser