You can fax from your computer using your internet connection, a fax service, or your phone line

You do not need a physical fax machine or a landline to send a fax from your computer. The easiest route depends on what you have available: an internet connection, a scanner or camera, and either a free online fax service or a paid subscription. Most people can send their first fax within 10 minutes using a web browser.

The document you want to fax needs to be in digital form — either a PDF file, an image file (JPG or PNG), or a document you can convert to PDF. If you have a paper document, you will need to scan it first using a scanner, a multifunction printer with scanning capability, or your phone's camera and a scanning app.

Key Takeaways

  • Free online fax services let you send one or two faxes per month at no cost, though they add a watermark and may limit file size.
  • You need the recipient's fax number and your own email address or phone number to send a fax online.
  • Paid fax services cost between $5 and $20 per month and let you send unlimited faxes without watermarks.
  • If you have a landline, you can use fax software on your computer to send faxes through your existing phone line.
  • Scanning a paper document takes an extra step but uses the same fax services once the file is ready.

Sending a fax using a free online service

Free fax services are the fastest option if you only need to send a fax occasionally. Services like eFax Free, Fax.plus, and HelloFax offer one or two free faxes per month. You create an account with your email address, upload your PDF or image file, enter the recipient's fax number, and send. The whole process takes about five minutes.

The trade-off is that free services add a watermark to your fax and may limit how large your file can be — usually 5 to 10 MB. If the recipient is particular about how the document looks, or if you need to send more than a couple of faxes per month, a paid service is worth the cost. Free services also do not give you a fax number to receive incoming faxes, so they work only for sending.

To use a free service: go to the website, create an account with your email, click the upload button, select your PDF or image file from your computer, enter the fax number you are sending to, and click send. Some services ask you to verify your email address before your first fax goes through. Check your email for a confirmation link and click it, then try sending again.

Using a paid fax service for regular sending

Paid fax services cost between $5 and $20 per month depending on how many faxes you need to send and whether you want to receive faxes as well. Services like eFax, Fax.plus Premium, and Hellofax Premium remove the watermark, let you send unlimited faxes, and give you a dedicated fax number so people can send faxes to you. They also store your fax history in an online account so you can look back at what you sent.

Most paid services let you send faxes through their website the same way free services do — upload, enter the number, send. Some also let you send faxes by email: you attach your document to an email and send it to a special address like 5551234567@fax.service.com, and the service converts it to a fax and sends it to that number. This is faster if you are already in your email program.

When you sign up for a paid service, you will be asked whether you want a new fax number or whether you want to port an existing fax number from another service. If you are starting fresh, the service will assign you a number. If you already have a fax number through another provider, you can usually transfer it, though this takes a few extra days.

Sending a fax through your computer's modem or phone line

If you have a landline phone connection and your computer has a modem (most laptops and desktops made before 2010 have one; newer ones usually do not), you can use fax software to send faxes directly through your phone line without using the internet. This method does not require a subscription, but it ties up your phone line while the fax is sending and is slower than internet-based faxing.

Windows computers come with a built-in fax application called Windows Fax and Scan. To use it, open the Start menu, search for "Windows Fax and Scan," and open the application. Click the "New Fax" button, enter the recipient's fax number, attach your document, and send. Your computer will dial the number through your modem and phone line.

Mac computers do not have built-in fax software, but you can download third-party applications like FaxTalk or eFax software. These work the same way: you open the application, enter the fax number, attach your document, and send. The software handles the dialing and transmission through your modem.

This method works only if your computer has a modem and you have an active phone line connected to it. Most modern computers do not have modems, so this option is becoming less common. If your computer does not have a modem, use an online fax service instead.

Scanning a paper document before faxing

If you have a paper document, you need to convert it to a digital file before you can fax it. The easiest way is to use a scanner. If you have a multifunction printer (a printer that also scans), place the document in the scanner tray, open the printer's software on your computer, click "Scan," and save the file as a PDF. Most printers save scans to your Documents folder by default.

If you do not have a scanner, you can use your phone's camera and a scanning app. Apps like Adobe Scan, Microsoft Lens, or Google PhotoScan take a photo of the document, automatically crop it, and convert it to a PDF. Download one of these apps, open it, point your phone's camera at the document, take a photo, and save the PDF to your phone. Then email the PDF to yourself or upload it to your computer using cloud storage like Google Drive or OneDrive.

Once you have the PDF file on your computer, use any of the faxing methods above to send it. The scanning step adds about five minutes to the process, but the rest is the same.

Troubleshooting common faxing problems

If your fax does not go through, the most common reason is an incorrect fax number. Fax numbers look like phone numbers but are not the same — they are dedicated lines for fax machines. Double-check the number with the person or organization you are sending to. If the number is correct and the fax still fails, the recipient's fax machine may be offline or out of paper.

If you are using an online service and the upload fails, your file may be too large. Try compressing the PDF by opening it in a PDF editor like Adobe Acrobat Reader or Preview (on Mac) and exporting it at a lower quality setting. Most fax services accept files up to 10 MB, so if your file is larger, compression will help.

If you are using Windows Fax and Scan and the fax will not send, your modem may not be properly connected or recognized by your computer. Open Device Manager (search for it in the Start menu), look for "Modems" in the list, and check that your modem is listed and has no warning symbols. If it does, right-click it and select "Update driver." If your modem is not listed, your computer may not have one.

Frequently Asked Questions

Do I need a fax machine to send a fax?

No. You can send a fax from your computer using an online fax service, fax software, or your phone line and modem. You only need a digital file (PDF or image) and the recipient's fax number.

Can I fax a document directly from Microsoft Word or Google Docs?

Not directly, but you can export the document as a PDF and then upload it to a fax service. In Word, go to File > Save As and choose PDF. In Google Docs, go to File > Download > PDF Document. Then upload the PDF to your fax service.

What if I do not know the recipient's fax number?

Call the person or organization and ask for their fax number. Fax numbers are usually listed on business websites or business cards. If you cannot find it, ask by phone — fax numbers are not always easy to locate online.

Is it safe to send sensitive documents by fax?

Faxing through an online service is as secure as email — your document travels over the internet encrypted. Faxing through a phone line is more secure because it does not go through the internet, but it is slower. For highly sensitive documents, ask the recipient whether they prefer fax or a different method like secure email or in-person delivery.

Can I send a fax to multiple people at once?

Most fax services let you enter multiple fax numbers on the same fax, and they will send to all of them. Some services charge per fax sent, so sending to five numbers counts as five faxes. Check your service's pricing before sending to multiple recipients.