What Is Online Faxing?

Online fax services let you send and receive faxes without using a fax machine. To send a fax, you typically generate a PDF or scan the document pages you want to send. After that, you upload the file to the fax service. You then fill out additional information, such as the recipient's name and fax number, and optionally add a cover page. The online fax service takes care of the rest. The recipient receives the documents just the same as if you had fed them through a fax machine. Sometimes, you can send a fax through email, which we'll cover a bit later.

To receive faxes through an online fax service, you have to have a paid account, which will get you a dedicated fax number. In most cases, you either log into a web portal to retrieve digital versions of faxes you receive, or they can be sent to your email.

If you plan to use an online fax service regularly, say, sending more than one or two faxes per month, you'll want an account with a paid subscription plan. Otherwise, you can get by using a free service, such as FaxZero, or you can pay per fax without a subscription using HelloFax (now owned by Dropbox and in some places referred to as Dropbox Fax).

How to Send a Fax Online

All the fax services included here offer a web interface, but their utility wildly varies. Well-designed software can inspire user confidence, while archaic services can just as easily undermine it.

Of the services we tested, HelloFax is the best when it comes to having a highly functional and clear web interface.

(Credit: HelloFax/PCMag)

When sending a fax from a web portal, all your attachments (that is, the fax pages) are sent as images. All the fax services we tested support a generous range of file types, though the file size limit varies. The majority of the services let you preview attachments before you send them. HelloFax also includes tools for creating and applying digital signatures.

For more details, see our article explaining how to send and receive a fax online.

How Much Does Sending Online Faxes Cost?

Most online fax services want you to sign up for a subscription and pay a monthly fee. Each subscription typically includes an allotment of pages that you can send each month. Some companies distinguish between how many pages you can receive and how many you can send. Other services offer a pool of pages, which is a more flexible approach. With a pool, if you send more faxes than you receive, you can make the most use of the total allotment.

Pooled-page plans also make it easier to avoid paying overage fees, which are per-page fees assessed when you exceed your monthly allocation. These fees are typically around 10 cents per page. HelloFax charges just 5 cents per page for overage, which is the lowest rate you'll find.

Depending on your service, your plan might not include international faxing, though faxes from the US to Canada and the UK sometimes do not incur extra costs. Some paid plans include international coverage. It's not unusual for an online fax company to charge an additional fee to send an international fax, sometimes on a graduated scale, depending on the recipient's location, and usually per page.

Setup fees are rare in the world of online fax services. Only one of the services we tested, eFax, charges one ($10). Between the setup fee, non-competitive prices, and eFax's merely average list of features, it didn't make the cut to appear in this list of the best fax apps.

What Is the Best Free Online Fax Service?

If you rarely send faxes, a free faxing service will do. Three services are the best for free faxing: Fax.Plus, HelloFax, and FaxZero.

Fax.Plus lets you send 10 pages for free, ever, from your account. Similarly, HelloFax lets you send 5 pages for free. FaxZero lets you send 5 faxes per day for free, and each fax can include 3 pages plus a cover. FaxZero's business model runs on advertisements.

(Credit: FaxZero/PCMag)

There's simply no reason to opt for a paid service if all you need to do is send a fax once in a while. If receiving faxes is a requirement for you, then you need a paid plan.

How to Fax From Your Phone or Tablet

The majority of online fax services offer Android apps and iPhone apps. With a mobile faxing app, you can just take a picture of a document and send it on its way. Of the services included in this list, Fax.Plus and RingCentral offer mobile apps.

We prefer online fax services to have dedicated mobile apps, but, at the very least, they should have a mobile website. FaxZero and SRFax have sites that are very usable via mobile browsers. HelloFax lets you send a fax from your mobile device, but you have to go through your email account to do it.

(Credit: Fax.Plus/PCMag)

How Can You Receive a Fax to Your Email (and Vice Versa)?

Modern businesses and workers are familiar with email workflows, and most of the fax services included here offer similar fax-to-email capabilities. In practical terms, fax services convert received faxes into email attachments, and conversely, turn email fields and attachments into their fax equivalent. As you can send and receive email from anywhere, this approach makes a fax service more universally available.

The process of sending a fax via email is fairly straightforward and doesn't vary much from service to service. You type the fax number—including country and area code—into the address line, followed by an email domain specific to the fax service (for example 12345678910@samplefax.com). The subject line and body text appear on the fax cover page, while any attachments appear as separate pages. Your fax number appears as the sender, so there's no confusion about where the message originated.

How to Choose a Fax Number

Most services let you select an area code and either assign you an available phone number for receiving and sending faxes or let you choose from a list of available numbers. Most also let you port over an existing fax number if you have one.

If you don't want people to have to pay to fax you, consider getting a toll-free fax number, which is usually free of charge once you have a paid plan. RingCentral offers vanity numbers for your fax number, though we only recommend RingCentral for medium to large businesses that send or receive a high number of faxes every month.

(Image: Getty/Just_Super)

Some industries still rely on faxing for various reasons, and knowing where to turn online when you need to send a fax to one of them is much easier than running out, pages in hand, to find a business that offers faxing services in-house.

But faxing isn't the only way to deliver documents, so be sure to check out the numerous secure methods for file sharing and sending encrypted email.