A mobile proxy routes your traffic through a real phone or modem holding a physical SIM card on a real carrier, so target sites see a genuine mobile carrier IP address rather than a server. Because hundreds or thousands of real subscribers share each carrier IP through CGNAT, mobile IPs carry the highest trust of any proxy type — which is why Proxy4G runs every plan on real devices with real SIMs and assigns them a 100% trust score.
How to use this glossary
The terms below are grouped loosely from the most fundamental (what a mobile proxy is) to the more technical (ASN, exit node, x402). Each definition is written to stand on its own in one to three sentences, so you can read any single entry without the others. Where a concept has its own in-depth page, the term links to it — for example, what is a mobile proxy, rotating vs dedicated, or SOCKS5 vs HTTP.
If you are comparing connection types before buying, the companion explainer mobile vs residential vs datacenter puts three of these glossary entries side by side. For prices per country, see pricing, and for the full list of carriers see locations.
Core terms
- Mobile proxy
A proxy whose exit IP belongs to a mobile network operator and is served from a real device with a physical SIM. Target sites see a carrier IP shared by many real subscribers, making the traffic look like an ordinary phone on 4G or 5G. See what is a mobile proxy and 4G proxies.
- 4G / LTE proxy
A mobile proxy whose underlying device connects over a fourth-generation (LTE) cellular network. It delivers low-latency carrier IPs suitable for browsing, scraping and account work; LTE is the baseline standard across Proxy4G's 43 carriers. Background: 4G on Wikipedia.
- 5G proxy
A mobile proxy on a fifth-generation cellular connection, offering higher throughput and lower latency than LTE. 5G is available on select carriers and countries — for example T-Mobile 5G (US), Three 5G (UK), SFR 5G (France), Vodafone 5G (Germany) and Jio 5G (India). See 4G vs 5G proxy and 5G on Wikipedia.
- CGNAT (carrier-grade NAT)
The address-translation layer carriers use so that one public IPv4 address is shared by many subscribers at once. This is the technical reason a mobile IP looks trustworthy and is hard to block without harming real users. References: CGNAT and RFC 6598. More: how mobile proxies work.
- IP rotation
Changing the exit IP address so successive requests appear to come from different addresses. On Proxy4G dedicated plans you rotate on demand (instantly via the dashboard or a reset link) or automatically every 1–60 minutes; shared plans auto-rotate every 5 minutes. See rotating mobile proxies.
- Sticky session
A configuration that keeps the same exit IP for a defined window so a login, cart or multi-step flow stays on one address. A dedicated port that rotates only on demand acts as a sticky session for as long as you need it. Compare in rotating vs dedicated proxies.
- SOCKS5
A general-purpose proxy protocol that forwards TCP (and UDP) traffic without inspecting it, so it works for browsers, apps, bots and tooling alike. Proxy4G supports SOCKS5 on every plan alongside HTTP/HTTPS. See SOCKS5 mobile proxies, SOCKS5 vs HTTP and SOCKS on Wikipedia.
- HTTP(S) proxy
A proxy that understands the HTTP protocol; the HTTPS variant tunnels encrypted traffic via the CONNECT method. It is the simplest option for web browsing and most scraping libraries, and is available on all Proxy4G plans with either username/password or IP-whitelist auth.
Connection types
- Residential proxy
A proxy that exits through an IP assigned by an Internet service provider to a home connection. It is more trusted than a datacenter IP but tied to fixed broadband rather than a cellular carrier, so it lacks the CGNAT-shared trust of a mobile IP. Side-by-side: mobile vs residential vs datacenter.
- Datacenter proxy
A proxy served from a server in a hosting facility. It is fast and cheap but its IP belongs to a hosting ASN, which sophisticated sites detect and block easily — the opposite of a mobile carrier IP. Proxy4G uses no datacenter IPs; every exit is a real SIM on a real device.
- ASN
An Autonomous System Number identifies the network that owns a block of IP addresses — for example a mobile carrier versus a cloud host. Anti-fraud systems read the ASN to judge whether an IP looks like a phone or a server, which is why a carrier ASN is far more trusted than a hosting ASN.
- Exit node
The final device an outbound request leaves from before reaching its destination; the destination sees the exit node's IP. On Proxy4G the exit node is a physical handset or modem with a SIM card on one of 43 carriers across 18 countries.
Trust, identity and payments
- No-KYC
Short for "no Know Your Customer" — buying without identity verification. Proxy4G requires no government ID, no name or address, no phone and no email verification; your account is auto-created on first order. See no-KYC proxy.
- IP trust score
A rating anti-fraud platforms assign an IP based on signals like its ASN, history and abuse reports. Genuine mobile carrier IPs score at or near the top because blocking them would also block real subscribers — Proxy4G plans run at a 100% trust score.
- Browser fingerprinting
Identifying or tracking a visitor from browser and device attributes (user agent, screen, fonts, canvas, time zone) rather than the IP alone. A clean mobile IP only helps if your fingerprint is consistent too, which is why proxies are often paired with an antidetect browser. Guide: set up a mobile proxy with an antidetect browser.
- x402
An HTTP payment protocol that lets an autonomous AI agent pay for a resource over the wire. Proxy4G implements scheme "exact" with USDC on Base: a request returns HTTP 402 with an accepts block, the agent signs an EIP-3009 USDC authorization, and re-sends it in the X-PAYMENT header to fund a balance and buy. See AI agents & automation and MCP.
Frequently Asked Questions
A 4G proxy exits through a mobile carrier IP served from a real phone with a physical SIM, behind carrier-grade NAT shared by many subscribers. A residential proxy exits through a home broadband IP assigned by a fixed-line ISP. Both are more trusted than datacenter IPs, but the CGNAT-shared nature of mobile carrier IPs typically gives them the higher trust score, which is why Proxy4G uses only real mobile devices.
Under carrier-grade NAT, one public IPv4 address is shared simultaneously by hundreds or thousands of real subscribers. If a site blocks that IP to stop one user, it also blocks every genuine customer on it, so platforms are reluctant to ban mobile carrier IPs outright. That shared-fate property is the core reason mobile proxies carry a high IP trust score.
IP rotation changes your exit IP so requests appear to come from many addresses; a sticky session keeps one IP for as long as you need a stable identity. On Proxy4G, shared plans auto-rotate every 5 minutes, while dedicated plans let you rotate on demand or every 1–60 minutes — and a dedicated port that only rotates on demand effectively behaves as a sticky session.
Use HTTP/HTTPS for ordinary web browsing and most scraping libraries; use SOCKS5 when you need protocol-agnostic forwarding for apps, bots or UDP traffic. Proxy4G supports HTTP, HTTPS and SOCKS5 on every plan, so you can pick per task rather than per subscription. See the SOCKS5 vs HTTP guide for the full trade-offs.
x402 is an HTTP-native payment protocol that lets an autonomous AI agent pay for a resource without a human checkout. Proxy4G implements it with scheme "exact" and USDC on Base: the agent gets an HTTP 402 with an accepts block, signs an EIP-3009 USDC authorization, and re-sends it in the X-PAYMENT header to top up a balance and buy proxies. It is for agentic automation, not manual buyers.