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PayPerFax accepts multiple file formats for faxing. Learn about the requirements and best practices for preparing your documents.

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Supported file formats

PDF

RecommendedMost reliable format

DOC/DOCX

Word DocumentsMicrosoft Word files

TIF/TIFF

Image FormatG3 compression supported

JPG/JPEG

Photo FormatImage files

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File size limits

Maximum file size: 8MB per uploadFiles larger than 8MB will be rejected.
If you have a large document, consider:
  • Compressing the PDF
  • Splitting into multiple faxes
  • Reducing image quality/resolution before converting to PDF

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How to attach files

1

Click 'Choose files'

On the PayPerFax web form, click the “Choose files” button
2

Select your file

Browse your computer and select a file to upload
3

Add more files (optional)

Click “Choose files” again to add additional documentsFiles will be faxed in the order you added them
You can attach multiple files. They’ll be combined into a single fax in the order uploaded.

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Format recommendations

Why PDF is best:
  • Most consistent conversion to fax format
  • Preserves layout and formatting
  • Works well with both text and images
  • Widely compatible
Tips:
  • Use black text on white background when possible
  • Avoid complex graphics or colored backgrounds
  • Test that text is readable at lower resolution
Microsoft Word documents work well for:
  • Text-heavy documents
  • Simple formatting
  • Letters and forms
Cautions:
  • Complex layouts may not convert perfectly
  • Fonts may be substituted
  • Embedded images should be high contrast
If your Word document has critical formatting, convert it to PDF first and review before faxing.
TIFF is the native fax format:
  • G3 compression supported
  • Black and white only
  • Direct transmission without conversion
When to use:
  • You already have fax-format files
  • Receiving faxes electronically and forwarding them
  • Maximum compatibility required
JPEG works for:
  • Scanned documents
  • Photos (though faxes are black & white)
  • Images of forms or papers
Tips:
  • Use high contrast (dark text, light background)
  • Ensure text is sharp and readable
  • Remember that colors will convert to grayscale

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Technical specifications

When you upload a file, PayPerFax:
  1. Validates the file format and size
  2. Converts to fax format (TIFF G3)
  3. Processes at fine quality: 204×196 dpi
  4. Converts to black and white (1-bit)
  5. Generates preview for your review
This takes 30-60 seconds depending on document complexity.
Faxes use standard resolution of 204×196 dpi (lower than typical documents). This is the universal fax standard worldwide and why faxes appear pixelated on screens.See Why Confirmations Look Low Quality for complete details.
Fax technology transmits in 1-bit black and white (not grayscale).Color conversion:
  • Colors are converted to grayscale first
  • Then converted to pure black or white (dithering)
  • Light colors may disappear
  • Dark colors become black
Avoid colored text on colored backgrounds - it may become unreadable.

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Preparing documents for faxing

1

Use high contrast

  • Black or dark text
  • White or very light background
  • Avoid gray text or watermarks
2

Keep layouts simple

  • Standard margins
  • Single column when possible
  • Avoid tiny fonts (12pt minimum recommended)
3

Test before faxing

  • Convert to grayscale on your computer
  • Zoom out to simulate lower resolution
  • Verify all text is readable
4

Combine multiple files

If you have multiple documents:
  • Either upload them separately (faxed in order)
  • Or combine into a single PDF first

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Common file issues

Solutions:
  • Compress the PDF using online tools or Adobe Acrobat
  • Reduce image quality in your PDF
  • Split into multiple smaller faxes
  • Remove unnecessary pages
This is normal: Fax format has lower resolution than modern documents.
  • Text should still be readable
  • Layout may shift slightly
  • Fine details may be lost
Use the preview to verify readability before sending.
Problem: Light colored text or backgrounds disappearSolution: Convert to high-contrast black-on-white before faxing
Not supported:
  • EPS, AI (vector graphics)
  • PSD (Photoshop)
  • RAW image formats
  • Compressed archives (ZIP, RAR)
Solution: Convert to PDF, DOCX, or export as JPEG/TIFF

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Multiple file handling

When you attach multiple files:
  1. Order matters: Files are faxed in the order you added them
  2. Combined into one fax: All files become a single transmission
  3. Total page count: All pages from all files are summed for pricing
  4. Preview shows all: The preview displays the complete combined fax
If you need to change the order of files, you’ll need to start over and upload them in the correct sequence.

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Minimum requirements

You must provide either:
  • At least one attached file, OR
  • A cover page, OR
  • Both
You cannot send a completely empty fax.

Step-by-Step Guide

Complete sending instructions

Step-by-Step Guide

Review your converted document

Low Quality Confirmations

Why faxes appear pixelated

Cover Pages

Add a text cover page