Free fax tools that run in your browser

Which fax tool do I need?

Most fax errands run into one of five questions, and each tool answers one of them. If you have the document and the number and only want to know what it will cost, use the cost calculator. If the number is the problem, because it is printed with a (0) or a dash or a leading 00, use the formatter first and then the calculator. If the page is the problem, a signed form, a stamped letter, a photo of a document, use the preview to see whether it survives at fax resolution. If you need a cover sheet because the machine or service you are using does not add one, the generator prints one. And if the fax has been sending for a while and you want to know whether that is normal, the transmission time calculator gives the expected range.

Why these tools are free and run in the browser

A fax carries a document someone did not want to email: a signed form, a medical record, a court filing, a tax notice. A tool that asked you to upload that page to check it would defeat the reason you are faxing it. So the preview reads the image with the browser’s own canvas and draws the result on the page; the number formatter and the cost calculator carry the app’s destination list and pack prices inside the HTML they were built from; the cover sheet prints from the page you filled in. There is no upload endpoint on this site. The only thing the site sends anywhere is the anonymous analytics tag described in the privacy policy, which sees that a page was visited and nothing you typed.

The tools are free because the questions they answer are the questions people have before they choose a fax app, and Faxvio would rather answer them plainly than hide the answers behind an install. The cost calculator prices the competition next to Faxvio at published App Store prices, with the date those prices were read; the number formatter tells you when a number is outside Faxvio’s list; the preview shows the same monochrome rendering the app shows before a page is spent. If the answer is that another service suits you better, the tools will have said so.

What the tools have in common with the app

Two of them run the app’s own logic. The number formatter and the cost calculator use a port of the engines inside Faxvio: the same normalisation of a typed number to the international form, the same resolution of shared dial codes such as +1 and +44 to a territory, the same allow-list of 37 destinations, and the same rule that toll-free, shared-cost and premium prefixes use two pages per page. The port is checked against the app’s own test vectors at every build, so a number the tool says is a service prefix is one the app will quote at two pages, and a number the tool refuses is one the app refuses before charging.

The preview reproduces what the app calls “as received”: every page rendered in one-bit black and white at fax resolution before sending, because the grey signature that looks fine on a phone screen is what arrives as a smudge. The app does it automatically for every page; the tool does it for one image at a time, on this site, for anyone.

The five tools at a glance

Each tool takes one kind of input and gives one kind of answer. None of them needs an account, a download or a connection beyond loading the page itself; the number formatter and the cost calculator work offline once the page is open, because everything they need is inside it.

When a tool is not enough

The tools stop at the edge of the page. A cover sheet does not send itself, a preview does not fix a faint signature, and the cost calculator cannot see a balance you already own. For the sending itself, Faxvio does what the tools describe: it scans the pages or takes a file, previews every page as the receiver will print it, generates the cover sheet without charging for it, quotes the pages before anything is deducted, dials, and writes a receipt when the receiving machine confirms. A fax machine at a shop does the same job for a per-page fee and no receipt; a subscription service does it for a monthly fee with an inbound number attached. Which of the three is right depends on how often you fax, and the calculator is the honest way to find out.

If a question about faxing is not answered by any of the five, write to support. Questions that arrive more than once become pages, and pages that need arithmetic become tools. Two candidates are already on the list: a page-count estimator for a PDF, so the cost calculator can read the document instead of asking, and a checker for the fax numbers that agencies print on their forms, which change more often than the forms do. Neither exists yet, and this page will say so until it does.

The example numbers on this site are reserved ones

Every fax number shown on this site and in the app’s screenshots is drawn from a range that regulators reserve for fiction, so no real machine can be reached by copying one. In the North American Numbering Plan, 555-0100 to 555-0199 are set aside for exactly this purpose; in the United Kingdom, Ofcom publishes ranges such as 020 7946 0000 to 020 7946 0999 for drama and demonstration use. The tools accept them like any other number, which is convenient for trying a tool without a real number to hand.

Facts the tools are built on

Bottom line

faxvio.com publishes five free fax tools that run in the browser without uploading anything: a cover sheet generator, a cost calculator, an international number formatter, a one-bit fax preview and a transmission time calculator. Two of them run the same number and quoting engine as the Faxvio app, checked against the app’s test vectors, so what they say about a destination or a price is what the app will do.