Sending with HTML

To allow users to easily construct faxes using server side frameworks, Phaxio accepts HTML input and renders content using a webkit renderer. Using HTML to render print media is a little quirky, so we’ve provided some guidelines on how our system views HTML content and normalizes it to PDF and images.


Phaxio uses a screen resolution of 800x600 when rendering content. The renderer runs on the public internet, so you should ensure that all assets referenced in your HTML can be accessed relative to your document or using an absolute URL. Avoid using color when possible, as all content will be converted to black and white for faxing. When passing a URL using HTTPS to Phaxio, ensure that the certificate is valid and all intermediate certificates are installed. Phaxio will verify the certificate chain when accessing your content.

Finally, Phaxio uses the Content-type header when accessing media on the Internet, so ensure that that header is set correctly for your content.

Special metatags

Phaxio uses special metatags when rendering your document. Below are some metatags available for customizing the rendering process.

Tag name Content Description
phaxioMediaType screen/print Defines which CSS media type is used to render content
phaxioOrientation portrait/landscape Specifies page orientation