Mobile proxy

A mobile proxy routes traffic through an address assigned by a mobile network operator — the same kind of address a phone on 4G or 5G uses.

#Why they are the hardest to block

Mobile networks place large numbers of subscribers behind a small number of public addresses using carrier-grade NAT. A single mobile address may represent hundreds or thousands of genuine users at once. Blocking it means blocking all of them, so filtering systems are markedly more tolerant of mobile ranges.

#The cost of that tolerance

• The most expensive category, by a wide margin.
• Higher and more variable latency than any other type.
• Addresses rotate on the carrier’s schedule, not necessarily yours.
• Smaller pools, since each address is a real SIM on a real network.

#When it is worth it

Mobile-only surfaces, and targets whose anti-bot systems have defeated every cheaper category. It is a last resort by design, not a default.

#Why carrier-grade NAT changes the calculation

Mobile networks have far fewer public addresses than subscribers, so carriers place many subscribers behind one public address using carrier-grade NAT. A single mobile address can therefore represent a large and constantly changing group of real people.

That is the whole reason mobile addresses are treated leniently. Blocking one risks refusing service to everyone sharing it, and the operator cannot tell which of them caused the problem. The tolerance is a property of the address sharing, not of any quality in the traffic.

#What you give up

• Cost. Mobile capacity is the most expensive of the four categories.
• Predictability. A radio path varies with signal, cell load and time of day.
• Control over rotation. The address may change when the carrier decides, not when you do.

Because of the last point, treat a mobile address as an exit node you observe rather than one you own. Verify the address at the start of each session instead of assuming it persists.