Filetypes: when to use what file

Part of being a professional designer is learning how to set up design files correctly.

From websites to print collateral to mobile app user interfaces, different situations call for different file types. A professional designer understands when to use the PDF format and when PNG makes more sense. But usage is only part of the puzzle.

Once the designer passes the final files to the client, the client is often left wondering, “Am I supposed to send a PDF or JPEG to my printer? Should I use PNG or JPEG on my Facebook page? What is an AI file?” When your design contract ends, it may be up to you, the client, to take the reigns on implementing your new designs.

Let’s review some common file types, why your designer set the file up this way, and a few appropriate ways to use each file.

There are two distinct types of files: raster files and vector files. Raster files use pixels to populate tiny squares with color. Vector files use points to populate tiny dots with color.

Let’s start with raster files:

.JPG

  • Best for use on your website or social media platforms (exception: photographs taken by a professional photographer; their high-end cameras result in a suitable resolution JPEG that can be sent to print)
  • For use online, without the need for a transparent background
  • Use in your blog posts, on Facebook posts, and spattered throughout your website content

.PNG

  • Best for use on your website or social media platforms (don’t send to print)
  • For use online, with the need for a transparent background
  • Perk: PNGs are compressed versions of JPEG files, resulting in quicker load times for websites with lots of graphics
  • Use for posting graphic artwork on your website

.GIF

  • Best for use on your website or social media platforms (don’t send to print)
  • For use online, when animation is needed
  • Use in your blog and social media postings

Now, on to vector files:

.PDF

  • Best for use in print (sometimes websites will offer downloadable PDFs)
  • Use to send a marketing piece to print; designers usually export a file as PDF when it includes graphic elements like typography, shapes, and lines as opposed to just a photograph
  • Perk: PDFs can usually be scaled up or down without losing resolution (unless a photographic image is embedded)
  • Use PDFs when you ultimately want to print something (an ad design in a newspaper or magazine, for example, or as a stand-alone brochure or marketing piece) or when you want to maintain very high resolution of graphics

.EPS

  • A slightly older file version that’s best for use in print
  • Used by your designer when they want to export a design from Adobe Illustrator that can later be opened in Illustrator by another designer and/or sent to print
  • Downside: this is a legacy file that may be disappearing as technology advances
  • Use when you’re passing a design file from one professional designer to another

Finally, there are native files (also called the master file).

These are files used by creatives who use industry-standard professional software. You’ll most likely have to hire a designer to manipulate a native or master file.

.AI

  • Designers export AI files when they export a file from Adobe Illustrator
  • Adobe Illustrator is used to create custom graphics and illustrations; logo designs take place in Adobe Illustrator

.PSD

  • Designers export PSD files when they export a file from Adobe Photoshop
  • Adobe Photoshop is used by designers when layered files for website and/or mobile app interface designs are required; it’s also used by professional photographers for manipulating pixels in a photograph

.INDD

  • Designers export INDD files when they export a file from Adobe InDesign
  • Adobe InDesign is used by designers for desktop publishing – creating multiple-spread books, magazines, and brochures

Other file types are available but these nine are the types that I use most often — and the file types I typically deliver to my clients.


Have a question about which file type to use?