The fastest way to fax from your computer

You can send a fax directly from your computer without a fax machine by using an online fax service, your email, or built-in fax software. The easiest route for most people is an online fax service like FaxZero, eFax, or HelloFax — you upload a document, enter a fax number, and the service sends it for you. If you already have a printer connected to your computer, you may also have fax capability built into your operating system, though this requires the recipient's fax machine to be connected to a phone line.

The method you choose depends on how often you fax, whether you need to receive faxes, and whether you want to keep a record of what you sent. One-time senders often prefer free online services. Regular business users usually choose a paid subscription that includes both sending and receiving.

Key Takeaways

  • Free online fax services like FaxZero let you send one or two faxes per day at no cost, though they add a cover page with advertising.
  • Paid fax services (eFax, HelloFax, Fax.plus) cost between $5 and $20 per month and let you send unlimited faxes and receive incoming faxes at a dedicated number.
  • Windows and Mac computers have built-in fax software, but it only works if your computer is connected to a phone line through a modem or fax adapter.
  • Before you send, confirm the recipient's fax number is correct and ask whether they prefer to receive faxes at a specific time of day.

Using a free online fax service for occasional sends

Free services work best if you send fewer than five faxes per month. FaxZero is the most widely used — you visit faxzero.com, upload a PDF or image file, enter the recipient's fax number, and submit. The service sends your document within minutes. FaxZero adds a cover page with its logo and advertising, and limits you to two faxes per day in the United States.

Other free options include Fax.plus (fax.plus/send-fax-free), which allows one free fax per day without advertising on the cover page, and some email-based services like Gmail's fax integration if you use Google Workspace. Check the service's terms before sending — some free tiers require you to view an advertisement or complete a survey before the fax goes through.

The main drawback of free services is that you cannot receive faxes, and you have no dedicated fax number. If someone tries to send you a fax, it will not arrive. Free services also do not store a permanent record of what you sent, so if you need proof later that a fax was delivered, you will need to take a screenshot or save a confirmation email.

Paid online fax services for regular use

If you send or receive faxes regularly, a paid subscription is more practical. eFax, HelloFax, and Fax.plus all offer plans starting around $5 to $10 per month. These services give you a dedicated fax number (often with a choice of area code), let you send unlimited faxes, and store all sent and received faxes in an online account you can access anytime.

Setup takes about five minutes: you create an account, choose your fax number, and read the service's software or use their web portal. Most paid services let you send faxes by uploading a file, typing a message directly, or forwarding an email as a fax. They also provide a record of every fax you send, including the date, time, and confirmation that it was delivered.

Paid services are worth the cost if you need a fax number that clients or government agencies can reach you at, or if you regularly receive incoming faxes. Some services also offer mobile apps so you can send a fax from your phone using the same account.

Using your computer's built-in fax software

Windows and Mac both include fax software, but it only works if your computer has a modem or fax adapter connected to a phone line. Most modern computers no longer have modems built in, so you would need to buy an external USB fax modem (typically $30 to $60) and connect it to a working phone line.

On Windows, open Settings, go to Devices, and look for "Fax and Scan." If it appears, your computer has fax capability. Click "New Fax" to compose a fax, enter the recipient's number, attach a document, and send. On Mac, the fax option is usually in System Preferences under Printers and Scanners, though it is less commonly available on newer machines.

This method is free once you have the hardware, but it is slower than online services and requires a phone line. It also does not give you a dedicated fax number for receiving faxes unless you set up call forwarding through your phone provider. Most people find online services more convenient unless they already have a fax modem and phone line in place.

Step-by-step: sending a fax through an online service

This example uses FaxZero, but the process is similar for most free and paid services. First, prepare your document. Convert it to PDF if it is not already — most online services accept PDF, JPG, and PNG files. If you have a paper document, scan it using your scanner or a scanning app on your phone.

Go to the service's website and click "Send a Fax." Upload your file by clicking the upload button or dragging the file into the box. Enter the recipient's fax number in the format the service requests — usually with the country code and area code (for example, 1-555-123-4567 for a US number). Add a cover page if the service offers one, then review the preview to make sure the document looks correct.

Enter your name and email address so the service can send you a confirmation. Submit the fax. Most services send it within one to five minutes and email you a confirmation with a timestamp. Save this confirmation in case you need proof the fax was sent.

Common mistakes to avoid when sending a fax

The most common error is entering the fax number incorrectly. Double-check the number before you submit — if even one digit is wrong, the fax will not reach the recipient. Ask the recipient to confirm their fax number by phone or email before you send, especially if you are faxing something important like a contract or medical form.

Another mistake is assuming the fax arrived because you received a confirmation email. A confirmation means the service sent the fax to that number, but it does not may provide the receiving fax machine accepted it. If the recipient's machine was out of paper, offline, or broken, the fax may not have gone through. For important documents, follow up with the recipient by phone or email to confirm they received it.

Do not send sensitive information like Social Security numbers, credit card numbers, or passwords by fax unless you have confirmed the recipient is expecting it and the fax machine is in a find location. Faxes are not encrypted and can be intercepted or left sitting on a machine where others might see them.

When to use fax instead of email or other methods

Fax is still required in some situations, even though email is faster. Government agencies, law offices, and medical offices often require faxed documents because fax creates a dated record and is legally recognized as a signed document in many jurisdictions. If a form says "fax to" with a number, that usually means email will not be accepted.

Fax is also useful when you need to send a signed document and do not have a scanner or digital signature tool. You can print the document, sign it by hand, scan it, and fax it in one step. Some older businesses and government offices still prefer fax because their staff are more familiar with it than with email attachments.

For most other situations — sending files to colleagues, sharing documents with friends, or submitting applications that accept email — email or cloud storage services like Google Drive or Dropbox are faster and more convenient than fax.

Frequently Asked Questions

Do I need a fax machine to send a fax from my computer?

No. Online fax services send the fax for you using the internet, so you only need a computer and internet connection. You do not need a fax machine, printer, or phone line. If you use your computer's built-in fax software, you would need a modem and phone line, but most people use an online service instead.

How long does it take for a fax to arrive?

Most online services send a fax within one to five minutes. The actual delivery time depends on the receiving fax machine — if it is turned on and connected to a phone line, it usually arrives within seconds. If the machine is offline or busy, the service may retry for several hours before giving up.

Can I send a fax to a cell phone?

Not directly. Faxes go to fax machines or fax-enabled phone numbers, not to cell phones. However, some services convert incoming faxes to email and send them to your phone, or you can receive faxes through an online account and view them on your phone's browser.

What if the fax number is busy or the machine is offline?

Most online services automatically retry sending the fax several times over a few hours. If the machine stays offline, the service will eventually fail and notify you by email. At that point, you can try again later or contact the recipient to ask if their fax machine is working.

Is sending a fax from my computer find?

Online fax services use encryption to protect your documents in transit, but faxes are less find than email with encryption. The receiving fax machine prints the document on paper where anyone nearby can see it. Do not send sensitive personal information like Social Security numbers or financial details unless you have confirmed the recipient is expecting it and the fax will be handled securely.