An ISP proxy gives you an address registered to an internet provider, served from a machine in a data center. A mobile proxy sends your requests out through a phone carrier's address, which many people share and which changes often. For one account that must look like the same person every day, the ISP proxy wins. A static ISP address is yours alone, it does not move, and at the median price it costs less than a gigabyte of mobile traffic. Mobile wins when the job needs a carrier address itself.
| ISP proxy | Mobile proxy | |
|---|---|---|
| Exit runs on | a server in a data center | a device with a SIM card |
| Address belongs to | an internet provider | a phone carrier |
| Shared with | nobody, when static | many users, through carrier NAT |
| Address over time | fixed for the rental | changes often |
| IP data label | ISP, or hosted | cellular, MOB |
| Usually billed | per IP and month | per GB |
What separates an ISP proxy from a mobile proxy?
Where the exit runs, and whose address it uses. An ISP proxy runs on a server. Its seller holds addresses registered to an internet provider and points them at that server. Spur sells detection data to websites, and it puts this plainly. ISP proxies use "IP addresses that appear residential but are hosted in data center environments". Our explainer on ISP proxies covers how sellers get those addresses.
A mobile proxy ends at a phone, a modem or a box with a SIM card on a carrier's network. The carrier hands that device its address, and your requests leave the internet from it. Our explainer on mobile proxies covers the devices. In both cases the registry and the network number, the ASN, name a consumer network. For the ISP proxy that network is an internet provider, and for the mobile proxy a carrier.
How do IP databases label each one?
They file the two apart. MaxMind's IP data gives each address a user type, with values that include cellular, residential and hosting. IP2Location sorts networks into usage types such as ISP for fixed lines, MOB for mobile networks and DCH for data centers. A site that reads either label can tell a mobile proxy from an ISP proxy without looking further.
The ISP proxy has a second tell. Its address belongs to an internet provider, while the machine behind it sits in a data center. Detection data that looks at the hosting side, like Spur's, can single it out. Our guide to how websites detect proxies covers the signals beyond the address.
How many people share the address?
On a mobile proxy, many. Carriers do not have enough IPv4 addresses for every phone, so they put their users behind a few public ones with carrier-grade NAT. Cloudflare writes that "a single IPv4 address may represent hundreds or even thousands of users". A 2016 study by Richter and colleagues found carrier-grade NAT in more than 90 percent of the cellular networks it looked at. RFC 6598 even sets aside a range, 100.64.0.0/10, for the networks inside it. Our explainer on CGNAT walks through how it works.
Sharing cuts both ways. RFC 7021 warns that blocking a shared address can "negatively impact legitimate users", which makes a site wary of blocking it. Yet Cloudflare found these addresses "subject to rate limiting three times more often than non-CGNAT IPs". The likely reason is that so many users share each one. A static ISP address serves one customer, so its record is yours.
Does the address stay the same?
A static ISP address does, for the whole rental. A carrier address moves. MaxMind scores how static an address is, from 0 to 99.99. Many cellular addresses score under one, and broadband addresses that rarely change score above thirty. MaxMind adds that the score helps decide "whether an IP address represents the same user over time".
Mobile sellers work with that. They rotate the address on a timer or per request, and a sticky session holds one exit for a while. For a login that has to look like one person for weeks, a fixed address fits better. Our guide to proxies for social media management covers the account side.
What does each cost?
The two are sold in different ways. We counted how sellers bill each type in our price records from August 3 to October 14, 2026.
- ISP, 60 sellers
- Mobile, 50 sellers
One static ISP address for a month cost a median $3.00 at the 18 sellers that sell a single address, from $1.20 up. Mobile traffic cost a median $4.00 per GB on the smallest plan at 33 sellers, and $2.20 on the largest. So one identity that moves more than about 0.75 GB a month costs less on the ISP address. To find your own break-even, divide the monthly price of one ISP address by the price of one GB of mobile traffic.
Two worked examples at those medians show where the line falls:
- Ten accounts that each move 2 GB a month. Ten ISP addresses cost $30 a month. The same 20 GB of mobile traffic costs $80.
- Fifty identities that each move 0.1 GB a month. Fifty ISP addresses cost $150 a month. The same 5 GB of mobile traffic costs $20.
Some sellers rent a whole mobile port by the hour, day or month instead, with unlimited traffic. Our comparison with MobileHop prices that model, at $225 for a month of its roaming US plan. ISP addresses often come with unlimited traffic as well. Our page on unlimited residential proxies explains why unlimited plans exist for ISP, datacenter and mobile.
How do you check which one you got?
Read the network of the exit. Our online proxy checker shows the internet provider or carrier behind each exit in its Network column, with a flag when the network belongs to a hosting company. A mobile exit should name a carrier. An ISP exit should name an internet provider, and a hosting flag on it is worth a question to the seller.
To check the registry yourself, ask ARIN's RDAP server about the exit address. It passes the query to the right regional registry, and the entity with the role "registrant" names the holder:
curl -s https://rdap.arin.net/registry/ip/YOUR-EXIT-IP
Which one should you buy?
For most account work, the static ISP proxy. Mobile loses there on price, on stability and on sharing. Pick by the job:
Pick a static ISP address when
One account must stay one person
the address is fixed for the rental
The identity moves steady traffic
cheaper above about 0.75 GB a month
The record should be yours alone
no carrier crowd behind it
Pick mobile when
The job needs a carrier address
to see what a mobile network's users see
Each identity moves little data
billed per GB, below the break-even
A new address per session is fine
rotating, or sticky for a while
Before you commit, test both on your own target, the way your tool will send requests. If the target accepts a datacenter or a residential exit, those can cost less again. Compare datacenter and residential, ISP and residential and mobile and residential.
Where do our ISP and mobile proxies stand?
Our static ISP proxies cost $2.70 per IP a month for one address. Our rotating ISP proxies are billed by the gigabyte, and both sit on our ISP proxies page. Our mobile proxies cost $1.50 per GB, rotating or sticky. Before you put either to work, run the exit through our proxy checker to see the network a site will read.
Sources
- Cloudflare, "One IP address, many users: Detecting CGNAT to reduce collateral effects", October 29, 2025: how many users share one address, and the rate-limiting finding.
- Richter and colleagues, "A Multi-perspective Analysis of Carrier-Grade NAT Deployment", 2016: carrier-grade NAT across cellular networks.
- RFC 6598 and RFC 7021: the shared address range, and the effect of blocking a shared address.
- MaxMind's GeoIP response fields, IP2Location's usage types and Spur's definition of ISP proxies, read October 22, 2026.
- Our price records of sellers' own price lists, August to October 2026.
