Yes. An online fax service sends a document from your computer to any fax number in the world without a modem, a phone line or a printer: you sign in to the provider's web page or desktop app, upload the file, type the recipient's number and send, and the provider's server dials the number and transmits the pages. The transmission report arrives by email. What it costs is the plan's monthly price, the pages it includes and the overage per page beyond them, which the Fax Line Index catalog records vendor by vendor from the vendors' own pricing pages.
What you need
An account with an online fax service and a document in a format the service accepts, PDF being the safe one because each page maps to one fax page. No hardware is involved on your side; the fax modem and the phone line that a machine needs live at the provider. Every vendor in the catalog sends from a web page; several also ship desktop apps and print-to-fax drivers that make the service appear as a printer, so sending is a matter of choosing it in the print dialog.
What it costs per page
Pages sent from a computer count against the plan's allowance exactly like pages sent any other way. Fax.Plus prints 200 pages a month on Basic at $6.99 with $0.10 per extra page; WestFax prints 500 pages on Solo at $14.99 with a 3 cent overage; CocoFax prints 60 pages on Lite at $9.99 a month with $0.20 per additional page. For a single fax and nothing more, FaxZero sends up to three pages free or 25 pages for $3.29 with no account, which is cheaper than any plan for one document and dearer than all of them from the second.
Limits worth knowing
Providers cap pages per fax: Fax.Plus prints 60 pages per fax on Basic and 200 on Business, FaxZero 25 on its paid option, so a long contract may go as two faxes. Dense pages transmit more slowly than text, and a busy receiving line is retried automatically. The confirmation the service emails is the transmission report, and it is worth keeping: it is the proof that the fax went, which a paper machine's slip never reliably was.
Questions people ask about can i send a fax from my computer
Can I send a fax from my computer without a phone line?
Yes. An online fax service uses its own lines; your computer only needs a browser. The plan's price and allowance are the whole cost.
Can I fax a PDF from my computer?
Yes, and PDF is the safest format because each page becomes one fax page. Word documents and images are accepted by most services too.
Can I send a fax from my computer for free?
For a single short fax, FaxZero prints free faxes of up to three pages, five a day. Anything longer or recurring is a paid plan; the catalog's entry prices start at $3.49 a month per line and $6.99 with pages included.