Troubleshooting

Improve fax quality

Tips for crisp, easy-to-read faxes

Tested solutions
Quickly resolved

Quick diagnosis

Quick tip

Low resolution, wrong format, or poor contrast

Use PDF format, choose high contrast (black text on white background), font size at least 10 pt.

Quick check

Check these items first

  • Document saved as PDF?
  • Black text on white background?
  • Font size at least 10 point?
  • Resolution at least 200 DPI?
  • Margins sufficient (min. 1,5 cm)?

Possible causes and solutions

Click a cause to view the solution

1

Text is blurry or pixelated

Cause

Resolution too low or compressed image

Symptoms

Letters are hard to read, edges are not sharp

Solution

Create the document at least 200 DPI. Use PDF instead of JPEG for text documents.
2

Grays are too dark or too light

Cause

Fax machines can represent only a limited range of grayscale

Symptoms

Photos or graphics are barely recognizable

Solution

Increase the contrast. Faxes work best with black-and-white documents. Avoid photos or convert them into high-contrast graphics.
3

Margins are cut off

Cause

Margins are too small, the recipient's fax machine prints with different margins

Symptoms

Text at the page edge is missing

Solution

Use margins of at least 1,5 cm on all sides. Do not place critical information at the very edge.
4

Font too small to read

Cause

Font size under 10 point, fine details get lost

Symptoms

Text is unreadable after faxing

Solution

Use a font size of at least 10 pt, preferably 12 pt. Avoid thin or ornate typefaces.

How to prevent the issue

  • PDF is the best format for faxes - formatting is preserved and quality is optimal.
  • Avoid colored backgrounds - faxes are transmitted in black and white.
  • Scan paper documents at a minimum of 200 DPI in black and white.

A clearly readable fax makes a professional impression. With these tips, you can ensure that your faxes reach recipients in optimal quality.

The optimal document

For the best fax quality, your document should have these characteristics:

  • Format: PDF preferred
  • Contrast: Black text on white background
  • Font size: At least 10 pt, preferably 12 pt
  • Typeface: Clear, readable fonts (Arial, Times New Roman)
  • Resolution: 200-300 DPI

Scan paper documents correctly

If you want to fax a paper document:

  • Scan mode: Black and white or grayscale (not color)
  • Resolution: 200 DPI minimum, 300 DPI for best quality
  • Format: Save as PDF
  • Alignment: Feed straight, skewed scans are harder to read

Avoid common mistakes

These mistakes often lead to poor fax quality:

  • Colored backgrounds: Often become too dark or illegible
  • Photos: Usually transmit poorly - avoid if possible
  • Small fonts: Anything under 10 pt becomes hard to read
  • Thin lines: Can disappear or appear broken

Frequently asked questions

Which file format delivers the best fax quality?

PDF delivers the best quality for faxes. The format preserves formatting, fonts, and layout precisely. JPG and PNG also work, but PDF is optimal for text documents.

What resolution should I use?

At least 200 DPI (dots per inch). For very detailed documents or small fonts, 300 DPI is better. Higher resolutions offer little benefit because fax machines have limited resolution.

Are colors transmitted?

No, faxes are generally transmitted in black and white or grayscale. Color content is automatically converted to grayscale. Check in advance whether your document is easy to read in black and white.

Problem still not solved?

If none of the solutions worked, a technical issue may be the reason. Our support team will be happy to help.

Go to help page

Problem solved?

Try again now - it will work this time!

1 € first page · 0,25 € each additional

Send fax again