Do you even need a stand-alone fax? Many all-in-one printers include the ability to send and receive faxes. If you only need to transmit the occasional fax, this might be a better solution because it saves valuable desk space. The main difference between all-in-one printers and a dedicated fax machine with extra features is that all-in-one printers usually excel at printing but are only so-so at faxing, while a fax machine excels at receiving and sending faxes, but might only be a so-so printer.
How much will you use the fax machine? Fax machines with a low initial cost often have higher costs for consumables, such as toner cartridges, drums, thermal-transfer ribbons and paper. Thus, for heavy fax users, a machine with a higher up-front cost may be the best long-term value because of its lower per-page cost. For light users, by contrast, a cheaper machine is usually the best value, because they'll use so little paper and toner that those costs will be minimal.
Do you have a need for speed? Inexpensive fax machines, like the Brother FAX-575, can take around 15 seconds per page to send a fax. By contrast, pricier machines with fast G3 modems, such as the Brother IntelliFax-2840, can send a fax in three seconds or less. The more pages you send and receive at a time, the more difference that extra speed will make.
How much memory do you want? Fax machines store incoming and outgoing pages in their onboard memory. Some fax machines use that capacity to perform multiple tasks at once, such as receiving one fax while preparing another to be sent. They can also save an incoming fax if they're out of paper and then print it once the paper tray is reloaded. The most basic models can store around 25 pages in memory, while high-end fax machines can hold as many as 500 pages. Memory backup is another plus; it will hold the saved pages in memory should power temporarily go out.
Which features and extra functions do you need? Many fax machines include extra functions such as copying, scanning and printing, which can blur the distinctions between a fax machine and an all-in-one printer. Desirable fax-centric features include caller ID, auto redial, fax forwarding, speed dialing and a built-in answering machine.
The dedicated fax machine is a dying breed. As all-in-one printers grow more affordable and more competent at performing a variety of tasks, the market for machines that are primarily designed to send and receive faxes is dwindling. Only four manufacturers -- Brother, Canon, HP and Panasonic -- still offer fax machines for the U.S. market, and all four of them together produce only a handful of different models. Moreover, online fax services make it possible to send and receive documents directly from your computer for anywhere from free (for occasional use) to $40 a month (for heavy use). Fortune magazine quotes Austin Allison, a tech CEO, as predicting that fax machines will disappear from the market within five to 10 years as the business world continues its shift "from physical to digital."