Phaxio vs Sfax (2026): which should you pick?

Pick Phaxio if

• Fits if you're a developer who needs to send faxes from your own software
• Works for low-volume senders who don't want a monthly plan

Look elsewhere if

• Not for you if you don't write code, because the main way in is the API
• Skip it if you want a free trial, as there isn't one
• Watch out: the API allows one request per second per account unless Phaxio raises it
• Pricey if you send a lot: volume rates only start at 50,000 pages a month

Pick Sfax if

• Fits if your medical office needs an audit trail on every fax
• Works for practices that fax from desktop programs through a print driver

Look elsewhere if

• Not for you if you want to see a price first, as none could be read from Sfax's pages
• Watch out: the trial is a paid plan you must cancel within 14 days, and monthly plans need 30 days' notice to cancel
• Skip it if you use Android, or Windows older than 11, as neither is supported
• Tight if you need several lines, since plans include one toll-free line and each extra is $5 a month

Phaxio

• Pricing is per page only: 7 cents in the US and Canada, 10 cents international, and 1 cent per fax received for the caller name add-on.
• Volume rates start at 50,000 pages a month: 5 cents, then 4 cents at 100,000.
• The API allows one request per second per account unless Phaxio raises it.
• Phaxio says it can be used for HIPAA workloads if its guidelines are followed, and it supports docx, pdf, tif, jpg, txt, html and png.

Sfax

• Prices could not be read: the Sfax pages on scrypt.com turned away automated reading, and the help center lists no prices.
• Plans include one toll-free line; each extra line is $5 a month on monthly plans or $48 a year on annual plans.
• Cancelling a monthly plan needs 30 days' notice by support ticket or email, with no refunds or partial months after the first 14 days.
• The Windows app supports only Windows 11 on x64 or x86, and the help center lists an iPhone app but no Android app.

Phaxio

JSON fax API

Send a fax with one call that takes a number and a file, or post a URL or a string of HTML to be rendered and sent.

Batching and retries

Batching and collision avoidance keep faxes from hitting a busy number, and retries for busy lines and other errors are configurable.

Callbacks and metadata

Failed callbacks are retried for three days, and each outgoing fax can carry metadata such as an order number or patient record number.

Numbers for receiving

Receive faxes on a US or Canadian number at $2 a month, or use the shared Phaxio number with a PhaxCode on the document.

Dashboard

A web console lists faxes, provisions numbers and lets you trigger a callback by hand.

Sfax

Web app with folders and a library

Send, forward, export and split faxes in the browser, sort received faxes into folders and keep reusable files in a document library.

Windows and Mac print drivers

Install the Sfax printer on Windows 11 or a Mac and fax a document from any program's print menu.

Annotate and sign faxes

Mark up and sign a received fax before sending it back, and pick a default fax cover page or buy custom ones.

Audit trail and HIPAA

Each fax keeps an audit trail of activity, and Sfax says it is HIPAA and GLBA compliant and signs a BAA on request.

Admin, SSO and permissions

Admins add users and fax lines, set permissions and IP safelists, and connect single sign-on through Okta, Microsoft Entra ID, Google Workspace and others.

API and file integrations

An API with callbacks lets other software send and receive faxes, and Box and ShareFile integrations move faxes into document storage.

Phaxio

• Pay as you go$10

  one-time top-up, used as you go

  No monthly fee. 7 cents a page in the US and Canada, 10 cents elsewhere; funds can recharge automatically.

Sfax

Pricing could not be confirmed. See scrypt.com.

Phaxio

• Other savings

  Volume discounts above 50,000 pages a month

  US and Canada pages drop to 5 cents at 50,000 a month and 4 cents at 100,000; international drops to 8 and then 7 cents.

Sfax

No public discounts listed.