Advantages and Disadvantages of PNG Images

In recent years, PNG, which stands for Portable Network Graphics, has remained popular. When it comes to web design, PNG is probably the most commonly used image format, alongside JPEG.  Due to their high-quality standards, even surpassing the quality of JPEG images, PNG images have gained favor over the years.  Why do we frequently use the PNG image file format, and what are its advantages and disadvantages?

The purpose of this article is to provide an overview of the advantages and disadvantages of using PNG images.

What is the PNG standard?

PNG is an acronym for Portable Network Graphics. It was in 1994 that the PNG format was developed following the patenting of the LZW data compression algorithm used in GIF and the requirement to pay royalties for its use. Originally developed as a better, non-patented alternative to the Graphics Interchange Format, or GIF, Portable Network Graphics (PNG) is a file format for compressed digital images.

The PNG file format supports all true colors and is widely used to transfer images over the Internet. PNG files support images with a resolution of 48 bits in true colors or 16 bits in grayscale. It is possible for pixels within PNG files to be transparent in both color and grayscale images. Files in this format are raster graphics.

Lossless Compression of PNG Images

In contrast to JPEG, the Portable Network Graphics or PNG standard maintains the quality of images even after repeated encodings and decodings. The PNG format uses a different compression technique than that used by JPEG, which does not result in any loss of information or quality in the image (lossless compression).

Due to PNG’s high image quality and lossless compression, it is also widely used by archivists and information scientists for the digitization of documents. Furthermore, millions of Web sites use PNG files due to their ability to conceal transparent areas and 24-bit color palette.

What are the Advantages of PNG?

PNG Image with Transparent Background from Public Domain

It is well known that PNG images have many advantages, most notably their high quality and transparency support. The following are the advantages of using the PNG image file type:

  • Support for full-color images – PNG is best for dealing with full-color images, which cannot do well with JPEG compression. PNG files are suitable for a variety of digital images, including photographs and graphics. In addition to the RGB colors (Red, Green, and Blue), PNG also has alpha.
  • Transparency Support – It is possible for pixels within PNG files to be transparent both for color and grayscale images. Transparency is one of the most significant differences between JPEG and PNG files. While PNG can handle transparency, JPEG cannot. Additionally, one of the biggest advantages that PNG image files have over other transparency formats (like GIF) is the size. Typically, PNG files offer increased compression and are smaller in size than GIF files.
  • Image fidelity – As a result of the lossless compression algorithms used in PNG images, the image fidelity is maintained. It simply means that images compressed with PNG retain their quality, details, and data regardless of how many times they are encoded and decoded. The quality does not diminish when a file is opened and saved again. With PNG, you don’t have to worry about your images getting blurry or warped, making it a great choice for charts with lots of figures and sharp logos.
  • Image Compression Efficiency – PNG format compresses images with clear transitions and large areas of solid color more efficiently than JPEG when you are saving images containing text, line art, or graphics.
  • Better screenshots and raster graphics –  PNGs are most commonly used for screenshots because they provide a near-perfect, pixel-by-pixel representation of a screen, rather than condensing groups of pixels. It is the recommended format to use when making screenshots due to the image quality retained. PNG is also a good choice for converting vector graphics into raster formats for display on systems without vector graphics.
  • Image Interlacing – PNG supports image interlacing. Images that are interlaced or progressive such as PNG images are displayed differently from normal images. A normal or baseline image is typically rendered from left to right and top to bottom, which means that the entire image is not visible until it is fully loaded. On the other hand, images that are rendered gradually, such as PNG, allow you to get a sense of the entire image before it is fully loaded. Images may look out of focus when first displayed, but as they load, they become increasingly clear. An advantage of this method is that it is especially useful when viewing images over a slow Internet connection.

What are the Disadvantages of PNG?

Large file sizes can be expected from PNG files.

It is true that PNG files offer many advantages, such as transparency, but this does not necessarily mean that you should use them at all times. The following are the disadvantages of using the PNG image file type:

  • Larger file sizes vs. JPEG – In some cases, a PNG image will display a non-noticeable difference in quality from a JPEG, but will be larger in file size. When this occurs, it is much better to use a JPEG file, since they are smaller in size and will load more quickly.
  • Larger file sizes vs. WebP – Despite the fact that Portable Network Graphics (PNG) is generally effective at compressing photographic images, there are lossless compression formats designed specifically for photographic images, such as WebP and DNG. Lossless WebP images are still 26% smaller than PNGs.
  • Not suitable for printing – PNG images are best used digitally. For printing purposes, CMYK color model support is better (ex. PDF, EPS).
  • No animations – PNG images do not support animations.

Final Thoughts: Using PNG

It is recommended that PNGs be used for screenshots and logos, as well as images that will require constant modification.

PNG is not suitable for incredibly large photographs due to its large file size, printing, as well as for images that need to load quickly.