ISP Proxies vs Mobile Proxies

What an ISP proxy is

The term "ISP proxy" is marketing language rather than a standard, so read each product page closely. In most offers it means a static IPv4 address that a provider leases or announces under an internet service provider's name, delivered from servers in a data center. You get the same address for the length of the plan, with the bandwidth and stability of server hosting.

The appeal is the label. When a site looks up the address, the registered holder is an ISP rather than a cloud host. IPinfo, for example, classifies each ASN as isp, business, hosting or education (IPinfo ASN data). An address under an "isp" ASN avoids the most obvious datacenter filter, which simply blocks known hosting networks.

Pricing reflects how cheap these addresses are to run. Decodo, as one example, lists dedicated ISP proxies from $3.33 per IP per month at 3 IPs down to $2.00 per IP at 2,000 IPs, with a shared pay-per-GB option from $1.30 per GB (Decodo ISP pricing, checked 30 October 2026). That makes ISP proxies the cheapest way to hold many fixed, non-hosting addresses.

The limits follow from the same design. The address is fixed, so anything tied to it, good or bad, stays with you. And the machine answering for the address is a server, which can show through in ways described below. Our guide to static residential IP proxies covers the static residential variant of this product.

What a mobile proxy is

With a mobile proxy, your requests reach the internet from a cellular modem or phone that holds a carrier SIM. The public address belongs to the carrier, and the carrier assigns it from a block that many subscribers share at once through carrier-grade NAT. The shared internal address space carriers use for that NAT layer is set out in RFC 6598.

Two things follow. First, the address looks like what it is: a phone network. MaxMind's connection type database has a separate Cellular label alongside Cable/DSL, Corporate and Satellite (MaxMind connection type documentation), and apps that care about mobile traffic can see it. Second, the same public address may be in use by ordinary subscribers at that moment, so a site that blocks it risks blocking real customers.

A dedicated mobile line adds control. On Coronium, each line is one device with its own SIM rented to one customer. You can keep the current IP as long as the carrier holds it, or change it from the dashboard, through the API, with a rotation link or on a timer with a 60-second minimum. HTTP and SOCKS5 are available on every line.

Detection: ASN, reverse DNS and the TCP handshake

Sites build a picture from several network signals. None of them is decisive alone, but together they separate an ISP proxy from a mobile line quickly.

ASN and connection type. An ISP proxy usually passes the first check, because the registered holder is an ISP. A mobile line reads as a carrier and as cellular. If a database labels the ISP range as business or corporate rather than consumer broadband, that is a hint that the block is not home connections. You can see the registered holder of any ASN through RIPEstat's AS overview call (RIPEstat AS overview) or our ASN lookup tool.

Reverse DNS. Many networks publish PTR records for their addresses. Some ISP ranges used for proxies carry names that mention static, business or a hosting partner, which home connections rarely do. Carrier ranges often have generic names or none. Run a reverse lookup on your exit and read the name the way a site would.

The TCP handshake. When you connect through an HTTP or SOCKS5 proxy, the target opens its TCP connection with the proxy's exit machine, not with your browser. That machine's operating system leaves traces in the first packets: window size, options, time-to-live. The p0f project describes identifying the operating system on both ends of a TCP connection from as little as a single SYN, and detecting connection sharing and proxying setups (p0f v3). A data center server usually presents a Linux server signature. If your browser claims Windows or iOS, the mismatch is visible.

Some Coronium lines let you set the operating system fingerprint the TCP stack presents. That setting is available today on lines in Georgia, Netherlands, Poland and Singapore. Our mobile vs residential proxies guide covers how browser and behavior signals add to these network checks.

Speed and session stability

ISP proxies win on raw consistency. A server in a data center has stable power, wired uplinks and low jitter. If your job is a high-volume API or page crawl that needs predictable response times, an ISP address is easy to plan around.

Mobile lines depend on radio conditions, the carrier's load in that cell and the generation of network the modem connects to. Throughput and latency vary through the day. For most account, browsing and app work this does not matter much, but for bulk transfer it does. Measure on your own target; our article on connection quality versus speed explains which numbers to watch.

Session stability is a different question from speed. An ISP proxy keeps one address for the whole plan, which suits long-lived logins as long as that address stays clean. A mobile line holds its address until you change it, although the carrier can also assign a new one, and an address change mid-session can log you out of a strict site. On a dedicated line you control rotation, so leave the timer off for sessions that must not move.

Cost model

The two products are priced for different jobs, and comparing their headline numbers directly can mislead.

ISP proxies are priced per address. At a few dollars per IP per month, holding fifty fixed addresses is inexpensive. Some offers meter bandwidth on top; others include it. Check whether the plan you choose is dedicated or shared, because shared ISP addresses carry other customers' history.

A mobile line is priced per device and period because a real device, SIM and carrier data plan sit behind it. On Coronium, the cheapest in-stock 30-day line today: From $97. Most carriers also offer 24-hour and 7-day periods. Data is not metered on dedicated lines, except Brazil, where lines include 20 GB a month.

Put simply: if you need many fixed addresses and the target tolerates server-hosted traffic, ISP proxies cost far less per IP. If the target scores mobile traffic differently or blocks your ISP ranges, one mobile line can do work that many ISP addresses cannot. See current plans and current prices by country and carrier.

A fit table

Read the table by the target, not by the proxy. If a site already accepts your ISP addresses, there is little reason to pay more per exit. If it blocks them, or the work is a mobile app, the carrier network is the part you are paying for.

Check your own exit in three commands

You do not need a vendor's word on what an address looks like. Three lookups from any terminal show most of what a site sees. Run them against the exit IP your proxy reports, not your own address.

# 1. Who holds the address and which ASN announces it
curl -s "https://stat.ripe.net/data/network-info/data.json?resource=203.0.113.10"

# 2. The reverse DNS name, if one is published
dig +short -x 203.0.113.10

# 3. What a web server sees as your public IP through the proxy
curl -s -x "http://USER:PASS@HOST:PORT" https://api.ipify.org

Replace the documentation address 203.0.113.10 with your exit. The first call returns the announcing ASN and prefix; feed the ASN into the AS overview call to read the holder's name. The second shows whether the PTR name hints at static, business or hosting use. The third confirms the proxy is actually in the path. If the holder is a hosting company, or the reverse name mentions a data center, expect a strict site to notice as well.

Moving a workload from ISP to mobile

If you are moving an existing job off ISP proxies, change one variable at a time. Keep the browser profile, account and target the same, swap only the proxy, and compare challenge rates over a few days. Expect fewer exit IPs: one line gives one address at a time, so a job that rotated across fifty ISP addresses may need several lines or a slower schedule.

Map each account to a line rather than to an address. On a dedicated mobile line the address changes when you rotate, so record the line, not the IP, as the account's home. Set the rotation timer only for jobs that benefit from new addresses, and leave it off for logged-in sessions.

Finally, check that your client supports the protocol you choose. Both HTTP and SOCKS5 work on Coronium lines; our SOCKS5 vs HTTP guide explains which suits each tool. To compare carriers and countries side by side, start from the mobile proxies overview.

Frequently asked questions