When you save a file on your computer, do you notice the few letters in the drop-down box below the name field? These are file extensions, and define which format your file saves as. Rarely is there a single format for one type of file, so you might be confused on how they differ and which are best to use.
Let’s compare two of the most popular file types each for images, documents, and audio files. Understanding the main differences between these major file types will help you decide which one to use in the future.
Know Your File Formats
Most digital information today takes three major forms — text, sight, or sound. Whether you’re talking about web pages, movies, or any other form of entertainment, information is presented to the audience in one or more of those three.
So, if you’re a producer of information, how do you know what file format to use? The answer boils down to how you want to distribute or use that file.
Images: PNG vs. JPG
Many people use JPG and PNG files almost interchangeably, and don’t understand how they affect file sizes. However, more experienced users know that not only will smaller image sizes reduce overall server memory consumption, they’ll also increase page load speed.
File size is the major difference between JPG and PNG, but the reasons aren’t obvious until you take a closer look at the images themselves. Below is a picture of a forest scene in JPG format.
This is a large image — over 1,000 pixels wide — and features vibrant colors and details. JPG (which stands for Joint Photographic Experts Group) has always been a popular image type for photographers sharing their work online. This is due to the fact that the compression of highly-detailed images involves finding redundancies in those files and compressing the data. Thus, beautiful images like the one above can still be presented with little quality loss. The resulting file size is a fraction of the original that may come straight from a digital camera.
However, because of the compression method, JPGs have some issues with contrasting edges in photos. This is most prevalent with text, signs, and the like. But if you zoom in far enough even into a high-quality image like the one above, you can see the quality reduction along those straight edges in the form of a “shadow” along the edge.
After saving the file multiple times, you can see the quality of the image reduce even further when you zoom back in. In this case, the meshing between edges becomes more pronounced, and you can see near highly-contrasting colors that there’s a greater amount of distortion.
The PNG Difference
Let’s next take a look at a highly-detailed PNG image of a park with strong contrasting black and white colors. Such an image would do a number to the JPG compression process. It isn’t too apparent from a distance, but much more obvious as you zoom in.
However, zooming into the PNG image, you can see that there’s no “shadow” effect or any significant distortion on the contrasting edges.
PNG stands for Portable Network Graphics, and was originally created as a replacement for the outdated GIF format. The PNG compression algorithm is non-lossy. When you save a PNG file again, the quality of the saved image is identical to the original.
Another huge benefit to PNG files is that they support image transparency. This allows you to use a transparent icon or image that blends seamlessly into a background without any ugly outline. See below the JPG image on the left, and the PNG image on the right over a blue background.
So, how do you choose which image format to use? Basically, if you want to provide high-quality photographs, save once as a JPG file. Avoid making too many modifications and performing multiple saves as you’ll lose quality.
On the other hand, if you’re creating icons or images with sharp contrasting colors — like images with text for example — then go with a PNG. Also, PNG is particularly valuable in web design when you need transparent images. Just keep in mind that PNG file sizes are typically larger than JPGs, so plan accordingly.
Documents: DOCX vs. PDF
Most people have sent a document online — whether it’s offering a formatted document via a website, or email documents when applying for a job. The most common document formats are Microsoft Word documents (DOCX) and Adobe PDF files.
Here’s what happens if you try to open a DOCX file from a web page:
That’s right, Word documents don’t work as embedded files — you can’t view them inside a browser because it’s a proprietary file format. You could open it via Office Online, but a novice user might not know to do that. If you aren’t certain whether your recipient has Microsoft Word installed, then it’s better to present your document as a PDF. This is easy thanks to a variety of PDF creation methods available.
You might think that Adobe Acrobat Reader is the de facto PDF reader, but you really don’t need it anymore. Indeed, Google Chrome and Microsoft Edge can open PDFs just fine, so your recipient doesn’t even need to have a desktop reader installed.
Are PDFs Always the Best Choice?
So, it might seem that PDF is always the way to go when you want to distribute documents. You can embed them in web pages, work well for small eBook formats, and they transcend operating systems. Do they have any downsides?
Of course, the catch is that editing a PDF is clunky, and advanced editing requires expensive software. When you’re collaborating with someone on a project, it’s important to have the tools that Microsoft Word offers for editing and collaborating. So, there’s a place for the DOCX format in sharing documents, but it comes down to how you want to use that document and why you’re sharing it.
If you’re sure that all recipients have Word installed and want them to edit it further, use DOCX. For times when you want to preserve a document’s format and want compatibility across all platforms, go with PDF. You should know how to reduce the size of a PDF file for more efficient sharing, too.
Audio: MP3 vs. FLAC
Perhaps you’re thinking of recording yourself playing guitar, or maybe you are buying music and have the choice to download a lossless FLAC or a compressed MP3. Which do you choose, and why?
This topic has seen plenty of debate around the internet. Plenty of music fans feel that MP3 files are a high-enough quality that they’re indistinguishable from the original recordings. Other folks — usually those within the music recording community — feel that the quality difference is quite noticeable. We’ve even tested audio compression’s effects if you’re interested.
To take a closer look at this, we downloaded a free classical song in lossless FLAC format. Played in Audacity, it was apparent that the music was crisp and clear.
The first test was exporting the original recording as an MP3 file using the default Audacity export settings. Then, opening both files side-by-side, we took a closer look at the sound files.
You can see subtle differences when you look at them together. It isn’t quite as obvious in this snapshot, but if you look close, you can see that the graphs for the MP3 file (the bottom two tracks) are not quite as dark as the top FLAC graphs. This is most apparent in the first section of the graph, where the far edges of the response (shown by the first arrow) are definitely more defined in the FLAC file.
I didn’t notice a substantial difference when listening to the two audio files, but music recording experts might pick up on distinctions between them.
Changing the MP3 Bitrate
So, I tweaked this up to the maximum value — 320 kbps — and then repeated the exercise above.
This time, the differences between the FLAC track and the MP3 track were almost indistinguishable from each other. Given, the 320 kbps MP3 was much larger than the 128 kbps file — 12 MB versus 5 MB, but it was still half the size of the original 24 MB FLAC file. Again, in the image below find the MP3 track as the bottom two graphs and the FLAC track at the top.
So, how do you decide on an audio format? If you’re recording music and want to maintain the highest possible quality, FLAC or any other lossless format is obviously the way to go. This will ensure that you’re capturing every nuance of the performance. Thankfully, external hard drives let you save tons of files for a low cost, so saving such audio files isn’t a huge deal.
However, if you’re a collector of music and you just want to store as much as possible on your portable player, MP3 is clearly the way to go. If you run a podcast and want to ensure that your listeners are not waiting forever for an episode to download, MP3 is the best choice.
Which Formats Are Your Favorite?
We’ve compared the differences between major formats of images, documents, and sound. In all cases, the format you opt for almost always depends on where you draw the line between quality and size. There’s a place for both, but you need to carefully consider how you’re going to use that file, and choose the right file format for the purpose.
When preserving quality is of the utmost importance, a lossless format like FLAC or PNG works best. Universal, space-friendly formats like PDF and MP3 ensure the lightest strain for those viewing them, and the best compatibility.
Does this help with your own file format dilemmas? Do you have any other file formats you prefer above those mentioned above? Share your own thoughts and insights in the comments section below.
Image Credit: Ulza via Shutterstock.com