IPv4 Proxies
An IPv4 proxy gives you access to a public IPv4 address through a proxy service. You can recognise an address in this format by its four numbers separated by dots: for example, 203.0.113.42.
The comparison between address versions is covered in IPv4 vs IPv6 Proxies. Here, we explain IPv4 itself: how its addresses are built, why their supply is limited, and how that affects the cost and history of the proxies you buy.
What are IPv4 and IPv4 proxies?
IPv4 stands for Internet Protocol version 4. It defines how data is addressed and carried between networks. Data travels in units called packets, each containing source and destination addresses. Network equipment uses the destination address to direct a packet towards the recipient.
An IPv4 address is the numeric address used in this system. It is assigned to a network interface: a device's physical or virtual connection to a network. A server can have several addresses, and an address can later be assigned to another server. The number is therefore not a permanent identifier of one physical machine.
A proxy is an intermediary service that sends requests on your behalf and returns the responses. With an IPv4 proxy, those requests reach the destination from the proxy's public IPv4 address. This is the address a website sees as the network source of the proxied requests.
When you buy a proxy, you pay for access to that service and its address resources for the agreed period. The IP is useful because the provider operates the server and network behind it: a written address alone cannot forward a request.
How an IPv4 address is built
The address 203.0.113.42 contains four parts: 203, 0, 113, and 42. Each part represents an octet, a group of eight bits. A bit is a binary digit that can be either 0 or 1.
Eight bits have 28, or 256, possible combinations. Counting from zero gives values from 0 to 255. This is why an octet can contain 203 or 42, but cannot contain 300. The dots separate the octets in the familiar decimal notation.
All four octets together contain 4 × 8 = 32 bits. For example, the decimal number 203 is written as 11001011 in binary, and 42 as 00101010. Each still occupies eight bits, even though one decimal number has three digits and the other has two.
The four numbers do not separately encode a country, city, provider, and device. Information about an address's network and estimated location comes from registration records, routing information, and location databases.
A proxy entry commonly adds a port after the address. In 203.0.113.42:8080, the colon separates two different values:
The IP address identifies where to connect; the port identifies the service at that address. Here, 8080 is the port on which the proxy service accepts connections. The port is separate from the four octets and is not included in the address's 32 bits.
The port is specified by the provider. Changing a port does not create another IPv4 address. A provider can, however, configure different ports to use different existing addresses when contacting websites; the connection settings alone do not tell you how many IPs the destination will see.
Why the number of IPv4 addresses is limited
A 32-bit value has exactly 232 = 4,294,967,296 possible combinations: about 4.3 billion. This is the size of the entire IPv4 address space. Some addresses are reserved for local networks and special purposes, leaving fewer available for ordinary public use.
The supply is also unevenly distributed. Address resources were allocated to networks over many years, and much of the available space is already held by organisations. An address can be allocated even when it is not currently serving an active device. A failed connection or an unanswered ping therefore does not show that the address is available for someone else to use.
When a registry reports that its free IPv4 pool is exhausted, it means it has run out of the stock used for ordinary allocations. ARIN, one of the regional organisations that administer address resources, reached this point in 2015. Previously allocated addresses continue to work, and existing resources can return to use or move between organisations.
For a growing proxy service, the constraint is access to those resources. Additional distinct public IPv4 addresses must come from the finite existing supply. That makes addresses a resource with its own availability and cost.
How networks share a limited supply of IPv4
Devices do not all need a separate public IPv4 address. Inside a home or office, they can use local addresses, such as 192.168.1.10. Another independent local network can use the same address without conflict: those addresses are not routed directly across the public internet.
NAT, or Network Address Translation, allows a router to translate local addresses into public ones. In the common form that also translates ports, a laptop and a phone can reach websites through one public IPv4. The router keeps track of their connections and sends each response back to the correct device.
Internet providers can apply the same principle at a larger scale, sharing public addresses among subscribers. This lets existing addresses serve more devices. It does not increase the number of distinct public IPv4 values: several users' traffic can still appear to a website under one address.
Where proxy providers obtain IPv4 addresses
Proxy providers obtain addresses through several arrangements. They can use address resources already registered to their organisation, rent resources from another holder, or receive addresses as part of a server or network service.
With a lease, the provider pays to use an existing range for an agreed period. With a transfer, rights to an address range move between organisations through the relevant registry's procedures. Such transactions often involve payment to the previous holder. In both cases, the addresses already exist within the IPv4 address space.
With hosting or connectivity, addresses may be supplied together with infrastructure. For example, a proxy provider can rent servers from a data centre and obtain additional IPs from that data centre's available resources. The proxy seller and the organisation listed in the address registry can therefore be different companies.
Obtaining the resources is only part of making them usable. The network must deliver traffic to the correct infrastructure, and the proxy software must handle requests. Installing another copy of that software does not generate new public IPs; the service needs both address resources and the equipment that makes them work.
How IPv4 scarcity affects proxy prices
Limited supply and continuing demand give IPv4 address resources a market value. A provider leasing addresses pays for access to them; a provider acquiring resources through a transfer commits money to their long-term use. These costs exist even when customers send little traffic.
This helps explain why a proxy service can charge by the number of IPs. Making more distinct addresses available means supplying more of a limited resource. A small workload does not necessarily make a large collection of IPv4 addresses inexpensive to provide.
The final proxy price also covers servers, network capacity, maintenance, and support. Several addresses can operate on the same server, spreading the equipment cost across them. That can reduce the cost of providing each proxy, while each distinct public IP still consumes an address from the available supply.
Scarcity therefore explains part of the price, but it does not set one universal rate. Providers have different acquisition costs, infrastructure, and service models. A higher price by itself does not establish a better address history or guarantee that a particular website will accept the proxy.
The history and reputation of an IPv4 address
An IPv4 address can pass through several periods of use: on a company server, in a hosting service, and later in a proxy provider's inventory. Buying a proxy starts your access to the service. It does not erase earlier activity associated with the address.
IP reputation is an assessment of an address based on information about its use. A website or security system may consider previous and current requests, complaints, suspicious behaviour, and the network the address belongs to. With shared access, other customers' current traffic can also affect how that IP is treated. Different systems collect different evidence and apply their own rules; there is no single reputation score used by every website.
History can work in an address's favour. Where a service considers past behaviour, an established record of ordinary traffic may be a useful signal. The relevant factor is what the system has observed: the age of the address alone does not establish trust.
History can also create problems. An earlier user may have generated abusive traffic or triggered an IP restriction. A new customer can then encounter additional checks or denied requests before doing anything that caused the original restriction. A new subscription does not automatically notify every website that the user behind the IP has changed.
These assessments can change. Operators can stop harmful activity, investigate complaints, and request corrections to particular listings; websites can revise their own restrictions. There is no single action that resets an address's reputation everywhere, and one service's decision does not determine how all others will treat it.
What “new” and “clean” IPs mean
These terms need a specific meaning to be useful. Three different claims can appear in proxy descriptions, and each says something different about the address.
New to the customer. The address has just been assigned to your service or added to the provider's available stock. This describes when you or the provider received it. It does not establish when the address first appeared on the internet or what it was used for before.
Clean in the checks performed. An address may be described as clean because it is absent from the blocklists checked or has no reported problems in particular databases. That result has a scope and a date. A public list cannot show every restriction maintained privately by a website.
Not previously used as a proxy. This is a claim about past use. An address might have served an ordinary company network before entering a proxy service. That history differs from never having been used at all, and the absence of a proxy label in one database does not prove the claim by itself.
A meaningful assessment therefore states what was checked: which sources, when, and for what kind of problem. An actual request to the required website provides evidence about current access to that website. Record the response, too: a timeout can come from a connection problem, while a login error can concern the account rather than the IP's history. Neither one request nor a blocklist result establishes a complete history or permanent acceptance.
Why restrictions can affect a whole network
A website can apply rules to an individual IP, a range of addresses, or an operator's network. Network-level restrictions can reflect activity observed across many addresses or a policy towards a particular source of traffic.
For example, a site may restrict traffic from a hosting network. An address in that network can be affected even if the site has no record of harmful requests from that particular IP. A check of the address's individual history would not fully explain the result.
If a restriction covers a whole range, replacing one proxy with another inside that same range leaves the rule applicable. If it covers the operator's network, even an address from a different range within that network can remain affected. Changing the address and changing the network are different changes.
This is why address history and network membership need to be considered together. A proxy can have no known individual reputation problem and still be unsuitable for a website's access policy. The practical result depends on how that website evaluates the address, its network, and the requests being sent.