What File Formats Can You Fax Online?

Whether you’re sending a signed contract, medical records, financial documents, or a business agreement, online faxing makes it easy to transmit important files without a traditional fax machine. However, before sending a fax, you may wonder: What file formats can you fax online?

The good news is that modern online fax services support a wide variety of file types, including PDFs, Microsoft Word documents, Excel spreadsheets, and image files. Instead of printing documents and scanning them into a fax machine, you can send digital files directly from your computer, smartphone, or tablet.

With FAXAGE, users can send documents in numerous formats through email, a web browser, or an API. Understanding which formats are supported and how to prepare your documents can help ensure successful transmissions while maintaining professional document quality.

What File Formats Are Supported for Online Faxing?

One of online faxing’s biggest advantages is its flexibility. Unlike traditional fax machines, which typically require paper documents, internet fax services allow users to transmit electronic files directly.

FAXAGE supports numerous file formats without requiring additional conversion software. These include commonly used business documents, spreadsheets, presentations, and images.

1. PDF Files (.pdf)

PDF, or Portable Document Format, is one of the most popular formats for online faxing.

Because PDFs preserve document layouts, fonts, images, and formatting, they’re especially useful for transmitting professional documents without unexpected changes to their appearance.

Common documents sent as PDFs include:

• Signed contracts and legal agreements
• Medical records and patient forms
• Insurance paperwork
• Tax documents and financial statements
• Business invoices and purchase orders

PDFs are also ideal for multi-page documents because multiple pages can be combined into a single file.

When you need to fax a PDF online, simply upload the document through your account or attach it to an email-to-fax message.

2. Microsoft Word Documents (.doc, .docx)

Microsoft Word files are another frequently used format for online faxing.

FAXAGE supports both older Word documents (.doc) and modern Word files (.docx), making it convenient to fax documents directly from your existing workflow.

Common examples include business correspondence, employment agreements, legal documents, client proposals, and administrative forms.

Additional supported word-processing formats include:

• Microsoft Word Templates (.dot, .dotx)
• Rich Text Format (.rtf)
• OpenOffice Writer (.odt)
• WordPerfect (.wpd)
• Microsoft Works (.wps)

Although Word files can be faxed directly, converting documents with complex formatting to PDF beforehand may help preserve their intended appearance.

3. Excel Spreadsheets (.xls, .xlsx)

Businesses frequently rely on spreadsheets to organize financial information, inventory, schedules, and operational data.

Fortunately, Excel spreadsheets can also be transmitted through an online fax service. FAXAGE supports both .xls and .xlsx files, along with OpenOffice Calc (.ods) and comma-separated values (.csv) files.

Spreadsheets are especially useful for faxing financial reports, invoices, inventory records, and accounting information.

However, spreadsheets sometimes contain wide columns, multiple worksheets, or extensive datasets. Before faxing, review the print layout to ensure that important information won’t be cut off or become difficult to read.

4. Image Files (.jpg, .png, .tiff, and More)

Not every document begins as a text file. Sometimes, the information you need to fax is stored as a photograph, scanned document, or digital image.

FAXAGE supports several popular image formats, including:

• JPEG (.jpg, .jpeg)
• PNG (.png)
• TIFF (.tif, .tiff)
• Bitmap (.bmp)
• GIF (.gif)
• WebP (.webp)
• HEIC (.heic)

This makes it convenient to fax photographed receipts, identification documents, handwritten forms, scanned paperwork, and other images.

For example, you can photograph a signed document using your smartphone and send it through the FAXAGE mobile fax app.

The app specifically supports sending PDF, PNG, and JPG files, along with photos captured using your phone’s camera.

5. PowerPoint, Text, and Other Document Formats

Online faxing isn’t limited to standard documents and images.

FAXAGE also supports several additional file types, including Microsoft PowerPoint (.ppt, .pptx), plain text (.txt), HTML (.htm, .html), Adobe PostScript (.ps), and HP Printer Control Language (.pcl).

This flexibility is particularly useful for businesses that work with specialized software or exchange documents across different platforms.

For a complete list of compatible extensions, visit our Internet Fax Features page.

What Is the Best File Format for Online Faxing?

Although several formats are compatible with online faxing, PDF is generally the best choice for most professional documents.

PDF files are particularly useful because they maintain consistent formatting across devices and operating systems.

For example, a Word document containing specialized fonts or complex tables may appear differently depending on how it’s processed. Converting that document to PDF first can help prevent formatting inconsistencies.

However, other formats may be better depending on your needs.

File Format	Best Use
PDF	Contracts, medical records, official documents
DOC/DOCX	Letters, agreements, business documents
XLS/XLSX	Financial reports, spreadsheets, invoices
JPG/PNG	Photos, receipts, scanned forms
TIFF	Multipage scans and document imaging
PPT/PPTX	Presentations and business materials

Ultimately, the best format is one that preserves document readability and meets the recipient’s requirements.

How to Send Different File Formats Through Online Fax

Once you’ve prepared your document, sending it is straightforward. FAXAGE offers several ways to transmit compatible files.

Send Files Through Email

With our email-to-fax service, you can send documents directly from your existing email account.

Simply create a new email, address it using the recipient’s fax number followed by @faxage.com, and attach the files you want to transmit.

For example, an email addressed to 3035551212@faxage.com would send a fax to that number.

You can attach multiple supported file types to the same fax, including PDFs, Word documents, and images.

By default, text and HTML attachments are excluded from email fax jobs to avoid unintentionally faxing email-body content; account settings can be adjusted when necessary.

Upload Files Through the Website

Another convenient method is sending documents through our online fax portal.

After logging into your FAXAGE account, navigate to the sending interface, enter your recipient’s fax number, and upload the documents.

You can combine multiple supported file types in a single fax job, eliminating the need to convert each document into an identical format.

The portal also allows you to monitor transmission status and review your fax history.

Fax Documents From Your Smartphone

For professionals working remotely or traveling, mobile faxing provides additional flexibility.

Our iOS and Android app allows you to send PDFs, PNGs, and JPGs, scan paper documents using your phone’s camera, and sign or annotate received faxes.

You can also import supported files from cloud storage platforms such as Google Drive, Dropbox, and iCloud Drive.

Send Files Through an API

Businesses with automated workflows can use the FAXAGE Internet Fax API to incorporate faxing into their existing applications.

This is particularly beneficial for healthcare organizations, financial institutions, and companies that regularly transmit large volumes of documents.

API integration helps reduce manual document handling and supports more streamlined communication processes.

Tips for Preparing Files Before Faxing Online

Even when a file format is supported, proper document preparation is essential for successful transmission.

Check Document Quality and Readability

Fax transmission can reduce image detail compared with the original digital file.

Before sending, ensure that text is legible, scanned pages are properly aligned, and images have sufficient contrast.

For physical documents, scanning at approximately 200 DPI is often suitable for standard faxing, while higher resolutions can help preserve finer details.

For more guidance, explore our scan-to-fax tips.

Review File Size and Page Limits

Large files may take longer to process, especially when they contain high-resolution images or extensive graphics.

FAXAGE supports outgoing faxes of up to 250 pages or 64 MB per fax job.

If your document exceeds these limits, consider reducing unnecessary image resolution, compressing the file, or dividing it into smaller transmissions.

Protect Sensitive Information

When faxing medical records, financial statements, legal paperwork, or other confidential information, document security is essential.

Our secure internet faxing features include SSL/TLS-protected web and API connections, secure email transport options, PGP support, and password-protected incoming fax PDFs.

Healthcare organizations can also explore our HIPAA-compliant faxing solutions to support their regulatory requirements.

Regardless of the file format, always verify the recipient’s fax number and follow your organization’s data-handling policies.

Frequently Asked Questions About Online Fax File Formats

Can I fax a PDF directly from my computer?

Yes. You can upload a PDF through the FAXAGE web portal or attach it to an email-to-fax message without printing the document.

Can I send multiple file formats in one fax?

Yes. FAXAGE supports combining different compatible file types within a single outgoing fax. For example, you can send a Word document, PDF, and JPEG image together.

Can I fax a photo from my phone?

Yes. The FAXAGE mobile app allows you to fax JPG and PNG images, including photos captured with your smartphone camera.

What format will I receive my incoming faxes in?

Incoming faxes are delivered in PDF format by default. TIFF is also available as an alternative, depending on your account configuration.

What if my file format isn’t supported?

You can convert the document to PDF or another supported format before sending it. Alternatively, our Print to Fax feature allows you to fax documents from Windows applications that support printing, even when their native file formats aren’t directly supported.

Send PDFs, Word Documents, Images, and More With FAXAGE

Online faxing has made document transmission more convenient than ever. Whether you’re sending a PDF contract, Microsoft Word document, Excel spreadsheet, or scanned image, there’s no need to rely on a traditional fax machine.

Understanding which file formats you can fax online helps eliminate unnecessary conversions, streamline workflows, and ensure your documents reach their intended recipients in a readable format.

With FAXAGE, you can take advantage of extensive file compatibility, convenient sending options, and robust security features designed for both individuals and businesses.

Ready to simplify the way you send documents? Explore our affordable online fax plans and discover how easy it is to send and receive faxes from virtually anywhere with an internet connection.