The Ultimate Guide to Image File Formats: JPEG, PNG, GIF, SVG, WEBP

by Federica Rustico

12 min read
Last Updated: May 26, 2023

JPEG, PNG, GIF, SVG, WEBP… these words sound like an alien language at first glance, but they’re just the acronyms to five of the most used image file formats online. The problem is there’s a lot of misunderstanding regarding when and why to use different types of image files. How are JPEG and PNG files different? In what file formats will I get the best possible picture quality? Will using particular file types slow down my website's performance? As marketers, it’s also part of your job to understand which image files are best for your business, and especially in which instance they should be used. 

Not that I want to state the obvious but images play an important part in digital communication and are utilized in a range of contexts, including advertising and email marketing in addition to websites and social media. But not all picture formats are created equal, and selecting the appropriate format for your project can make a significant impact on the final product's quality, file size, and degree of compatibility with other software and hardware. Today, we’ll go through everything you need to know about the five most common image file formats you'll come across online. Let’s get this party started (and leave the confusion behind us)!

Image compression

Before we go through each of the five image formats mentioned above, let’s go through something called image compression, aka the technique of lowering an image's file size without sacrificing quality. It's a tool for reducing an image's file size, making it easier to work with online and in mobile apps, and saving space. In regard to image compression, you'll frequently hear the terms "lossy" and "lossless", as they refer to two distinct categories of compression methods.

Lossy compression is a technique for reducing an image's size by throwing away some of the image data. This technique is frequently employed for images with a great deal of information and color, such as photographs, and can reduce file sizes. When an image is compressed, however, some of the data contained within it may be lost. Common examples of lossy image formats include JPEG and WEBP.

However, lossless compression can lower an image's file size without altering the quality of the image itself. Compared to lossy compression, this technique can result in larger file sizes but is preferred for images with a transparent background, such as logos and icons. When an image is compressed, however, its quality is not compromised. The image formats PNG, GIF, and WEBP are all examples of lossless formats.

Image file formats: when to use each file type

To sum it up, lossy compression reduces file size by removing unnecessary information, but at the expense of image quality. With lossless compression, the size of the saved file can be decreased while maintaining the same high quality of the original image.

Raster vs. Vector images

In digital graphics, the two most common image formats are raster and vector. The primary distinction between the two is in how photographs are saved and presented. Raster images, also called bitmap images, are constructed from a grid of pixels, with each pixel having its own color value. Raster images have a fixed resolution that is proportional to the number of pixels in the grid; increasing the size of a raster image makes the grid's individual pixels more obvious, reducing the image's overall quality. Photographs, images with a lot of detail, and images with a lot of different colors all work well as raster images. JPEG, PNG and GIF are all popular raster image formats.

In contrast, vector images are composed of equations that specify the image's lines, curves, and colors. Unlike pixel-based graphics, vectors scale well without degrading in quality. Vector pictures are the best option for logos, icons, illustrations, and any other graphics that need to be scaled or altered without compromising quality. SVG, EPS, and AI are typical vector picture file types.

More realistic and intricate graphics can be made with raster images as well. They excel in circumstances that call for a highly detailed and crisp image. They're not great for photographs that need to be scaled or edited, though, because they suffer quality loss when enlarged. On the other hand, vector pictures are ideal for making illustrations and graphics that can be scaled without losing quality. They work wonderfully for scalable logos, icons, and other images that need to look good at any size. And because they scale well without losing quality, they're perfect for use in print projects.

Obviously, there isn't one size fits all approach and both raster and vector picture formats have their benefits and drawbacks. Photographs and photos with a lot of detail benefit most from the raster format, whereas graphics and illustrations that need to be enlarged or edited without losing quality benefit most from the vector format. So when you're deciding on an image format, it's vital to think about its final destination and purpose.

JPG image format

The acronym "Joint Photographic Experts Group" (or "JPG") refers to the file format used to store digital images. I know, it’s a long acronym, but it gets across the general idea of what .jpg files are best used for: images. A jpg file is the preferred format for photos that will be displayed online.

Image file formats: when to use each file type

If you use a professional camera like a Canon to snap your pics, your photos will be saved in a RAW format. RAW images are files that contain the raw data from a digital camera's sensor without any processing or compression. In other words, RAW photos retain all of the original data captured by the sensor, such as color, brightness, and exposure, in contrast to other image formats such as JPEG or PNG, which are processed and compressed by the camera.

Photos saved in RAW format are cumbersome and huge because they contain so much information. Amazingly, jpegs are able to compress all that data without noticeable loss of image quality, making them ideal for sharing online. JPG files can be further compressed to reduce their size. When you need to post JPEG images to a website, a great free online tool to reduce their file size is TinyJPG.

Because image quality degrades with each save, you shouldn't keep saving the same JPG over and again since they’re going to look pixelated. If you're working with a file in Adobe Photoshop or Illustrator that has a transparent background and you save it as a JPG, the background will be changed to white.

When to use JPEGs? 

Because of its tiny file size and compatibility with most devices and software, JPEGs are ideal for displaying pictures and detailed images on websites and mobile apps. Images of products, photos of nature, and other close-ups are all good examples of where you might use this.

PNG image format

Portable Networks Graphics is what png stands for. In addition to being perfect for use in web design as the name suggests, the .png format is recommended for logos, social media graphics, illustrations, etc., because it allows for the highest possible image quality to be preserved.

In comparison to a lossy format like JPEG, the size of a.png file will always be greater if you save the same content in both formats. The loading time of your website would increase if you uploaded a photo as a png file. Keeping the same level of quality in the visuals requires a greater file size, but this extra space is well worth it.

You can get even more space saved by processing your PNG files through TinyPNG. The image quality is preserved while the file size is drastically reduced because of TinyPNG's use of smart lossy compression. The quality of a PNG file will not degrade no matter how many times it is saved, which is not the case with JPG files. Graphics and logos that will be placed on top of a colored backdrop on a website should be saved as png files because of the format's capability for transparent backgrounds.

When to use PNGs? 

For logos and icons that need to appear on websites and mobile apps but have a transparent backdrop, PNGs are the way to go. They are also compressible without sacrificing quality. Use logos, icons, screenshots, and other images with a translucent background as examples.

PNGs are also used in Adobe Photoshop, Adobe Illustrator, and other graphic design programs to preserve picture quality during editing or to save images with a transparent background.

Images in GIF Format

Graphics Interchange Format (GIF) images have been available for over 30 years, but their popularity has skyrocketed in the last few years because of the explosion of social networking and instant messaging apps. GIF is an acronym for "graphics interchange format," and it is most widely known for its ability to store moving images. They are a lossless picture format that can be used to make simple graphics or short animations with a small number of colors.

Image file formats: when to use each file type

The great news is they are widely supported by both hardware and software, allowing for easy viewing and sharing across multiple systems. Usually, GIFs are frequently utilized to inject some lightheartedness and individuality into online discussions and social media posts. It is possible to use a GIF's sequence of images to communicate a message or tell a story. They can also serve as visual aids to explain a procedure or explain a complicated idea to a group of people. However, pictures and complex images are not recommended for GIFs because of the quality loss that can occur due to the reduced color palette.

When to use GIFs? 

When it comes to social media, websites and messaging apps, GIFs shine when used for quick animations and straightforward graphics with a small palette. Use cases include everything from an animated icon or button to a brief animation. Check out all you need to know about GIF marketing as a tool to boost your brand’s engagement

Illustrations in Svg Format

The letters "svg" indicate Scalable Vector Graphics. Until now, we've only discussed raster-based file formats, all of which suffer from blurriness when increased significantly. Raster-based file formats are digital photographs stored in a pixel grid. In a pixelated image, each individual dot, or pixel, has a specific color value, and the image is constructed by displaying these values in a predetermined sequence. Because of their vector-based nature, SVG files can be resized without compromising image quality. Only SVG files can compare in quality to those in use today.

In reality, SVG files are just a string of mathematical equations that specify the various attributes of an image. This ensures that their high standard is maintained regardless of how large an operation becomes. And that means you can't just drag and drop them onto your Squarespace page as you would with a.jpg,.png, or.gif file. This svg code has to be pasted into a code block.

Svg files can only be made with a dedicated piece of software. Photoshop and other raster programs won't cut it; instead, use Illustrator, Sketch, or another vector-based program. SVGs are great for simple visuals like logos and icons. In addition to looking crisper than a png file, their reduced file size means they won't slow down your website. The one drawback is that there is more of a learning curve involved in correctly developing and installing them.

When to use SVGs? 

Because of their flexibility in resizing without loss of quality and their small file size, SVG files are ideal for usage in mobile applications. Logos, icons, and other forms of vector art are all prime examples of this type of graphic's application.The flexibility and adaptability of SVG pictures make them ideal for use in gaming apps, in graphic design software and apps that make use of visual aids like maps, diagrams.

Google’s WEBP file

Google created the cutting-edge WEBP (Web Picture format) image format in 2010. It was made to be more space efficient than JPEG and PNG while keeping image quality high. Because it works with both lossy and lossless compression techniques, it offers a lot of flexibility.

When utilized for photos, WEBP can drastically speed up a website's load time. The user experience is enhanced, and it is especially helpful for photos that are displayed at lower sizes. It's a modern format, so browsers like Chrome, Firefox, and webp all play nice with it.

Image file formats: when to use each file type

Some older browsers and devices may not support WEBP, and it is not as extensively supported by image editing tools. It also lacks PNG's support for transparency.

In conclusion, WEBP is a cutting-edge picture format that outperforms JPEG and PNG in terms of both file size and image quality. In the case of website images, it is especially helpful because it can shorten the time it takes for the page to load, thereby enhancing the user experience. Although it does enable transparency, it is not as extensively used as PNG and is not supported by all image editing applications.

When to use WEBPs? 

WEBP images are fantastic for web pages since they may drastically cut down on page load times, which in turn improves the user experience. They shine brightest when applied to frequently-loaded, small-sized pictures like thumbnails, as well as those that are presented at larger sizes. They’re also ideal for online e-commerce platforms since they improve page load times and, in turn, the user experience for shoppers.

Wrapping up

Many factors, including file size, quality, and compatibility, should be taken into consideration when selecting an image format. It's like deciding what to wear to a party; you want to be comfortable and look your best, but also not stand out too much.

Consider the file size as a top priority. Avoid being the person who sends a huge file that takes forever to open. Using an image format like JPEG or WEBP will result in a smaller file size, which is beneficial for speedy loading times. Other formats, such as PNG or GIF, will result in a larger file size, but they are ideal for images that need to maintain quality when compressed.

Image quality should also be taken into account. If you care about how you look in your clothes, you should care about how you look in your photos. Some formats, like PNG and GIF, maintain quality even when compressed, whereas others, like JPEG, may suffer quality loss. Obtaining success requires striking a balance between the two.

When deciding whether lossless or lossy compression is preferable, another key consideration is the compression method. You can always wear your original outfit again, just like with lossless compression you can keep all your party attire after the event. Using lossy compression is like getting rid of old clothing: it helps you save space but at the expense of some information.

Some formats, like PNG, support transparency, while others, like JPEG, do not. Transparency is important in the same way as being honest with your friends is important. In the end, harmony is essential. It's important to check if the picture format can be read by the devices and programs that will be used to view or edit the image. Like wearing the appropriate footwear to a party, because no one wants to be the one relegated to the grassy knoll in a pair of stilettos when everyone else is dancing the night away.

Frequently Asked Questions

Why do we need to consider the image format of an image?

By learning the differences between picture file types and how they are used, you can save time during the editing and sharing processes. Knowing the final destination for each photograph and taking into account its intended use, required resolution, and file size is crucial.

Is JPEG or PNG better quality?

PNG's primary benefit over JPEG is lossless compression, which ensures that image quality is maintained regardless of how many times the file is accessed and saved. Detailed, high-contrast photos are no problem for PNG either.

What types of images work best as a GIF format?

GIFs are ideal for animations, line art, clip art, images with sections of solid color, charts, and graphic text. They're not idea for images with too many hues as they can only store up to 256 colors.