What happens to a page when it is faxed
A fax is not a copy of your file. The sending side turns each page into a grid of black and white dots, 1728 across, and sends it down a phone line one row at a time. In fine mode there are 196 rows per inch; in standard mode, 98. There is no grey and no colour, only ink or no ink. Anything in between is approximated with a dot pattern, and the receiving machine prints whatever it gets.
That is why a document that looks perfect on screen can arrive with missing lines, black smudges or print too small to read. Most of these problems are easy to fix once you can see them, which is what the preview above is for.
How to make a document fax-friendly
- Use black text on white. Dark ink comes through crisp. Light grey text, pale form lines and watermarks break up or vanish, so darken anything the recipient needs to read.
- Don't rely on colour. Red and blue print as black, yellow and light blue fade to almost nothing, and highlighter disappears. Point things out with bold, underlining or a box instead.
- Keep text at 10 pt or larger. Fine resolution holds about 6 pt before letters run together; standard needs about 8 pt. Fine print on forms is the usual victim.
- Leave out big photos and dark backgrounds. They turn into grainy or solid black patches, and a busy page takes much longer to send than a page of text. If a photo matters, crop it to what the recipient needs.
- Use Letter or A4, portrait. Other sizes are scaled to fit the fax width, and landscape pages are turned or shrunk, which makes their text smaller.
- Remove the password. A password-protected PDF can't be opened to be faxed. Print or save it as a new PDF first.
Faxing a scan or a phone photo
Scans and photos are where most bad faxes come from. A grey scanner background or a shadow across a phone photo becomes a speckled or black area. Scan in black and white (sometimes called text or document mode) at 200 dpi, or photograph the page flat, in daylight, filling the frame. When you add photos here, Faxio evens out the paper to white before checking, which is the same clean-up it applies when you send.
How long a fax takes and what it costs
A typical page of text takes 30 to 60 seconds to transmit; pages with photos or shading take longer. The checker adds that up for you. With Faxio a fax of up to 10 pages is $2.99, with no account, no subscription and your credit returned if the fax fails. See pricing.
Frequently asked questions
How accurate is the fax preview?
It draws each page at real fax width (1728 pixels, about 204 dpi) and line count (196 lines per inch in fine mode, 98 in standard), then turns grey into black-and-white dots the way fax software does. The receiving machine, its paper and its toner still vary, so treat it as a close guide, not a guarantee.
Is my document uploaded when I check it?
No. The checker runs entirely in your browser. Your file never leaves your device unless you press Fax it now and then send the fax.
What is the difference between fine and standard resolution?
Both are 204 dots per inch across. Fine sends 196 lines per inch down the page, standard sends 98, so standard is faster but small text and thin lines get blurry. Faxio sends in fine resolution.
Why does my coloured or grey text disappear?
A fax has only black and white. Dark colours such as red or navy come out black, but pale colours and light grey become a sparse dot pattern or nothing at all. Use black text on a white background for anything the recipient must read.
Can I fax a photo of a document?
Yes. Add the photo here and it is turned into a PDF page with the paper evened out to white, which is what Faxio sends. Take the photo straight on, in good light, with the whole page in the frame.
How much does it cost to send?
Checking is free. Sending with Faxio costs $2.99 for a fax of up to 10 pages, $4.99 for 11 to 30 pages and $7.99 above that, with no account or subscription.
Looks good?
Check your document above and press Fax it now, or go straight to send a fax online for $2.99 →