Sending a fax online in 2026: the complete guide

Short answer: in 2026, sending a fax requires neither an analogue line nor a fax machine. A browser, a PDF and the recipient's number are enough: a gateway converts the document, dials the number over the telephone network and returns a transmission report. The trip usually takes between thirty seconds and three minutes.

Why the fax still hasn't gone away

Every year for two decades, the death of the fax has been announced. Every year, court registries, health insurance offices, medical practices and part of the legal profession keep receiving them. The reason is not nostalgia: it is the evidentiary status of the transmission report.

An email proves that a message left a server. A fax report proves that an identified machine answered, accepted the document and confirmed it page by page. That difference — slight in appearance — is enough to keep the fax alive in any procedure where a filing must be time-stamped and enforceable.

There is also a more mundane constraint: a fax machine depends on no inbox to watch, no spam filter, no expired password. In a department where the desk changes hands every eight hours, that counts.

What you actually need

The list is short:

• a document, ideally a PDF;
• the recipient's number, in the correct international format;
• an email address, to receive the transmission report.

That is all. No account, no application, no card details. The gateway handles the rest: it rasterises each page in black and white at 204 × 196 dots per inch — the standard Group 3 resolution — then negotiates the transmission with the remote machine.

Formats that survive, and formats that fail

PDF is the only format that never surprises anyone. Office formats must be converted before rasterisation, and that conversion carries two classic risks: non-embedded fonts get substituted, and reflowable layouts recompose. A table that fitted on one page can end up spread across two.

Images pose the opposite problem: a photo taken on a phone contains far too many shades of grey for a binary signal. The result often arrives black or unreadable. If you must transmit a photographed document, convert it to PDF first and push up the contrast.

Dialling the number correctly

This is by far the most common cause of failure, and it is entirely avoidable.

A fax number is dialled exactly like a phone number: country code, then the national number without its leading zero. For France, 01 23 45 67 89 becomes +33 1 23 45 67 89. A leading zero kept by mistake — +33 01 23… — produces an invalid number that the network rejects without any explicit error.

We maintain two reference pages for this: the list of international dialling codes and the list of available countries, which states the expected format for each destination.

For French public bodies, the fax directory lists the numbers of the main agencies — useful when the official website only shows a contact form any more.

How long it really takes

A standard page of text goes out in thirty to forty seconds. A ten-page document takes two to three minutes. Those figures cover the transmission itself, once the connection is established.

What stretches the delay is almost never the volume: it is the recipient. A busy line triggers another attempt a few minutes later. A machine out of paper will sometimes accept the connection and then abort halfway through. A switchboard that falls through to voicemail will never answer with a fax tone.

In practice, expect a successful transmission within five minutes, and assume that beyond three failed attempts the problem lies with the number or with the equipment at the other end.

Confidentiality: what to know

A fax is not end-to-end encrypted. The leg between your browser and the gateway is — that is TLS, like any web page. But the final segment, between the gateway and the recipient's machine, travels the telephone network in the clear.

In concrete terms that means two things. First, the document physically emerges onto a tray, in an office, where it sits until somebody picks it up. Second, a fax is not the right channel for credentials or banking details. For a medical certificate sent to a practice that accepts nothing else, on the other hand, the risk is comparable to that of paper mail.

In summary

• The fax survives for its transmission report, not out of habit.
• A PDF, a correct international number and an email address are enough.
• PDF is the only format without nasty surprises; avoid raw photos.
• Never keep the leading zero after the country code.
• A normal transmission completes in under five minutes.
• The final leg is unencrypted: no credentials, no banking details.

Frequently asked questions

Do I need a fax machine to send a fax online?

No. The gateway plays that role: it holds the telephone lines and the sending equipment. All you need is a browser and a document. Only the recipient needs a fax machine or a receiving service.

How do I know the fax arrived?

The transmission report emailed to you states how many pages were actually transmitted and the status of the connection. A partial send — three pages out of five — appears explicitly, so you can resend without waiting to hear from the recipient.

Can I send a fax to a mobile number?

No. The Group 3 protocol assumes a stable analogue connection, which a mobile network does not provide. The number must belong to a landline connected to a fax machine or to a receiving gateway.

Is the service really free?

Yes, and with no per-user quota. The lines and the hosting are funded by donations. The exact terms are set out in our FAQ.