If you have shopped for a KVM switch you have probably seen the name Adder next to a price that made you close the tab. A four port Adder secure switch can cost more than the two computers plugged into it.
That price is not a brand tax. It is what you pay when a product is built for a broadcast gallery or a defence control room rather than a desk. Here is who Adder actually is, and how to tell whether any of it is relevant to you.
From publishing to KVM
Adder was founded in 1984 by Adrian Dickens, and not as a hardware company. It started life as Adder Publishing. The name changed to Adder Technology in 1986, and the business moved into computer peripherals.
It is still based in Cambridge, England, and moved to Bar Hill just outside the city in 2012. It opened a Customer Experience Center at its Cambridge headquarters in February 2026.
The company has stayed private for its whole existence, which is unusual in this industry. Its three main rivals all ended up inside larger groups: Raritan went to Legrand in 2015, Avocent to Emerson and then Vertiv, and Black Box has changed hands more than once.
In November 2025 Adder went a step further and moved a majority shareholding into an Employee Ownership Trust. Forty-one years in, the company is now owned largely by the people who work there.
What they actually make
Adder builds four things, and the distinction matters when you are reading a product page.
Desktop KVM switches. The AV4PRO family. Four to eight computers, one keyboard and mouse, and crucially up to four monitors at once. Our catalog carries the dual, triple and quad head DVI versions, plus DisplayPort and the equivalent VGA models. Multi-head is the point here. Most consumer switches handle one or two screens.
Secure KVM. This is the part that explains the pricing. Switches like the AVSC1102 and AVSC1104 are certified to EAL4+ and designed against Tempest requirements, with smart card and CAC support. They exist so that an operator can work on a classified network and an unclassified one from one desk without any possibility of data crossing between them. The isolation is physical, not software.
KVM over IP and extenders. The ADDERLink ALIF line, such as the ALIF1104T HDMI transmitter and the ALIF2112T dual link DVI extender, moves the machine out of the room entirely. Put the noisy, hot workstation in a rack somewhere else and leave only a screen and keyboard at the desk. The AdderLink IPEPS does the same job over an ordinary network connection.
Matrix switching. The AVX4024 and the AdderView DDX30 let many users reach many machines, any to any. This is what sits behind a broadcast gallery or a trading floor.
Who buys this
Adder states that around 60% of its production is exported to Europe and the United States, through a distribution network covering more than 60 countries, with offices in the US, UK, Germany, the Netherlands and Singapore.
The customers it names are broadcast, post-production, industrial control rooms, transport and medical imaging. That list tells you the design priorities: uptime, pixel-exact video, zero switching lag, and in the secure range, provable separation between networks. Nobody specifying a product for an air traffic control desk is optimising for price.
The recognition follows the same pattern. Adder has taken Deloitte Fast 50 placings for eight consecutive years, holds a Queen's Award for Enterprise, and has won Best of Show awards at IBC, ISE and NAB every year from 2023 to 2026 for products including the ADDERLink INFINITY 3000, the ADDERView Matrix and the Adder API.
Those are trade show awards from broadcast and AV industry press. They are a reasonable signal of standing inside that world and tell you nothing about whether the product suits a home office.
Should you buy one
Mostly no, and it is worth being direct about that.
Buy Adder if you are running three or four monitors off multiple machines and need them to switch together cleanly, you need certified network separation, you want the computer in a different room from the desk, or you are specifying for a facility where a failure costs real money.
Do not buy Adder if you want to switch one monitor between a work laptop and a gaming PC. A switch at a tenth of the price does that, and our guide to the best KVM switches covers the options that make sense at a desk. If your issue is specifically two screens, dual monitor KVM switches is the more useful read, and if you game, start with whether KVM switches support 144Hz, because many do not.
The honest summary: Adder is very good at a problem most people do not have.
For the other names you will meet in this category, see who ATEN is, who Raritan is and what happened to Avocent. They started in the same place and ended up serving very different buyers.
The thing worth stealing from their product line
One idea from the professional world is worth borrowing even if you never buy the hardware.
Adder's extender products exist because the best place for a computer is often not the place where you sit. Heat, fan noise and cable clutter are design problems in a control room, so the industry solved them by separating the machine from the desk.
The consumer version of that is cheaper than it used to be. A long HDMI or USB-C run, or a basic extender pair like the XDIP/P-US, will get a desktop into a cupboard. You keep the performance and lose the noise.
Where the information here came from
Company history, founding date, the 2025 Employee Ownership Trust transition, the award record and the export and distribution figures are from Adder's public record as summarised on Wikipedia. Product specifications are from our own catalog entries, which are built from manufacturer documentation.
We do not have a commercial relationship with Adder.