The fastest way to fax from your computer
You can send a fax directly from your computer without a fax machine or phone line. The method depends on what you have available: an internet connection and a fax service, a printer that supports faxing, or software that connects to your existing phone line. Most people use an online fax service because it works on any computer and stores copies automatically.
The three main routes are online fax services (eFax, HelloFax, Fax.plus), built-in fax software on Windows or Mac, and fax-capable printers. Online services are the most reliable for regular use. Windows and Mac both include fax tools, but they require setup and work best if you already have a fax number. Printers with fax capability need a phone line connection, which fewer homes have now.
Key Takeaways
- Online fax services let you send faxes from any computer with internet, store copies in the cloud, and cost between $5 and $20 per month depending on volume.
- Windows Fax and Scan (built into Windows 10 and 11) and Mac's native fax tools are free but require a fax modem or USB adapter and an active phone line.
- To send a fax, you need the recipient's fax number, a document in PDF or image format, and either a service account or fax software configured on your computer.
- Online fax services typically deliver within minutes and send a confirmation email showing whether the fax went through.
- If you receive faxes regularly, online services are cheaper than maintaining a dedicated fax machine or phone line.
Using an online fax service
Online fax services are the easiest option for most people. You create an account, upload or compose your document, enter the recipient's fax number, and send. The service routes your fax through the internet to the recipient's fax machine or online account. Popular services include eFax, HelloFax, Fax.plus, and RingCentral Fax. Pricing usually runs $5 to $20 per month, with limits on how many pages you can send and receive each month.
To send a fax through an online service, log into your account, click the option to send a new fax, and upload your document. Most services accept PDF, Word, Excel, image files (JPG, PNG), and sometimes scanned documents. Enter the recipient's fax number in the format the service requests—usually with the country code and area code. Add a cover page if you want one, review the details, and click send. You will receive a confirmation email within minutes showing whether the fax was delivered.
The main advantage is that you keep a digital record of every fax you send and receive, which is stored on the service's servers. You can search your fax history, read copies, and forward faxes to other people without printing. If you travel or work from multiple locations, you can send faxes from any device with a web browser.
Sending a fax on Windows using built-in tools
Windows 10 and Windows 11 include a fax process called Windows Fax and Scan. To use it, you need a fax modem—either built into your computer (rare on modern machines) or connected via USB. You also need an active phone line connected to the modem. If your computer does not have a fax modem, you can buy a USB fax modem for $30 to $60.
Open Windows Fax and Scan by typing its name into the Windows search bar. Click "New Fax" and select your document. The process will ask you to enter the recipient's fax number and optionally add a cover page. Review the settings, then click send. Windows will dial the fax number through your phone line and transmit the document. The process takes a few minutes depending on document size.
This method works well if you already have a phone line and fax modem set up, but it is slower than online services and requires your computer to stay on during transmission. You also cannot send faxes while someone is using the phone line.
Sending a fax on Mac using native fax features
Mac computers can send faxes through the Print dialog in most applications. Open the document you want to fax in any program—Word, PDF viewer, email, or web browser. Press Command+P to open the Print dialog. In the bottom left, click the dropdown menu that says "PDF" and select "Fax PDF". Enter the recipient's fax number and click "Fax".
Like Windows, Mac faxing requires a fax modem and active phone line. If your Mac does not have a built-in modem, you will need a USB fax modem. The fax will transmit through your phone line, and you can check the status in the Print & Scan system preferences.
This method is convenient if you are already working in an process and want to fax directly without opening separate software. However, it has the same limitations as Windows faxing: it requires a phone line, ties up your modem during transmission, and is slower than internet-based services.
Using a fax-capable printer
Some multifunction printers have built-in fax capability. If your printer has a fax modem and is connected to a phone line, you can send faxes through the printer's control panel or through your computer's print dialog. Check your printer's manual to see if it supports faxing and how to configure it.
To send a fax through a fax-capable printer, open your document and select "Print". Choose your fax-capable printer from the printer list. Some printers will show a fax option in the print settings; others require you to use the printer's touchscreen to enter the fax number. The printer will dial the number and transmit the document through its phone line connection.
This option works if you already own a compatible printer and have a phone line available. The downside is that you do not get a digital record unless you scan the document first, and fax-capable printers are becoming less common as online services replace traditional faxing.
Preparing your document for faxing
Before you send a fax, make sure your document is in a format the fax service or software accepts. Most services accept PDF, JPG, PNG, TIFF, and sometimes Word or Excel files. If you have a paper document, scan it first using a scanner or your phone's camera, then save it as a PDF or image file.
Check that the document is readable and all text is clear. Fax transmission can reduce image quality slightly, especially for small text or light colors. If you are faxing a contract or legal document, make sure signatures and dates are visible. Test with a small document first if you are using a new service or method.
For online services, keep file size under the limit specified by your service—usually 10 to 50 MB per fax. If your document is larger, split it into multiple faxes or compress the file. Most services will reject oversized files and send you an error message.
Comparing cost and reliability
| Method | Setup Cost | Monthly Cost | Speed | Best For |
|---|---|---|---|---|
| Online fax service | None | $5–$20 | Minutes | Regular faxing, multiple locations, digital records |
| Windows Fax and Scan | $30–$60 (USB modem) | Phone line cost | 5–10 minutes | Occasional faxing, existing phone line |
| Mac native fax | $30–$60 (USB modem) | Phone line cost | 5–10 minutes | Occasional faxing, existing phone line |
| Fax-capable printer | Included with printer | Phone line cost | 5–10 minutes | Occasional faxing, existing phone line |
Online fax services are the most cost-effective for regular use because you pay a flat monthly fee with no hardware investment. They are also the fastest and most reliable—faxes typically arrive within minutes, and you get a confirmation email. If you send fewer than five faxes per month, the per-fax cost of an online service is lower than maintaining a phone line.
Built-in fax tools on Windows and Mac are free but require upfront hardware investment and an active phone line, which many people no longer have. They work well if you already have both. Fax-capable printers are convenient if you own one, but they are becoming harder to find and still require a phone line.
Frequently Asked Questions
Can I send a fax if I do not have a phone line?
Yes. Online fax services send faxes through the internet, not a phone line. You only need an internet connection and a computer. Built-in fax tools on Windows and Mac require a phone line or USB fax modem, so they are not an option without one.
How long does it take to send a fax?
Online fax services deliver within minutes, usually one to five. Built-in fax software and fax-capable printers take five to ten minutes because they dial through a phone line. You will receive a confirmation email or notification showing whether the fax was delivered.
What happens if the fax number is wrong?
Online services will attempt to send the fax and notify you if delivery failed. Built-in fax tools will show an error message if the number does not connect. Always double-check the fax number before sending, especially for important documents.
Can I send a fax from my phone instead of my computer?
Yes. Most online fax services have mobile apps for iPhone and Android. You can upload a document, enter the fax number, and send from your phone the same way you would on a computer. Some services also let you fax by email—you attach a document to an email and send it to a special fax number.
Do I need to keep my computer on while the fax is sending?
With online fax services, no—the service handles transmission on its servers. With Windows Fax and Scan, Mac fax, or a fax-capable printer, yes—your computer or printer must stay on and connected to the phone line until transmission is complete.