A guide to image file formats and image file types.
Looking for a guide to file formats for images but not sure where to start? Learn the strengths of the most common image file formats and make sure your pictures look their best.
Have you ever wondered what the differences are between the dozens of image file formats? Each format has its strengths, and you should know when and where to use them. Read on to learn more about the most common image file formats.
Why do image file formats matter?
Whether you need to print family photos or upload graphics to your company’s website, it’s important to select an image file type that fits your size, quality, formatting, and shareability needs. While some image files take up significant space and cannot be reduced in size, you can compress others easily.
You’ll also need to keep your image editing needs in mind, as some formats are only compatible with specific image editors or are difficult to modify. Other factors to consider are animation capabilities, color limits, data retention, and transparency features.
What are the different image file types?
Before you choose a file format, it’s important to understand the different image file types. There are several categories that define an image file’s capabilities:
- Vector image files. These file types are ideal for resizing images, as they are endlessly scalable. The image proportions are calculated and automatically adjusted using line art equations, making it simple to modify your images without affecting file size or image clarity.
- Raster image files. Rather than using algorithms, raster image files are based on pixels. The number of pixels and number of pixels per inch (PPI) or dots per inch (DPI) determines the image resolution. Raster images can be more difficult to scale without affecting the image quality.
- High-resolution files. Images that have more PPI or DPI have a higher resolution, although this doesn’t always guarantee the image will appear crisp and clean. Depending on whether you need a web or print image, you’ll also need to pay attention to image dimensions and device requirements.
- Low-resolution files. Images with fewer pixels or that are stretched will often appear blurry. If you need to enlarge a low-resolution image, you may need to use a program that can adjust the resolution while retaining the pixel quality.
Image file formats list: What are the most common image formats?
The most common image file formats include JPEG, GIF, PNG, TIFF, BMP, and PDF. Read on to learn more about which files will best meet your imagery needs.
JPEG — Joint Photographic Experts Group
JPEG (or JPG) is a lossy image file format, meaning its quality decreases with the file size. It’s the best choice for nearly all online images and for some printed photographs and artwork. JPEG is your go-to option for adding images to websites and documents.
GIF — Graphics Interface Format
GIF is a lossless, lightweight image file format ideal for small graphics on websites and in emails. It supports transparent elements and animated graphics. If you see a small animated image on the web, you’re probably looking at a GIF. However, GIFs are limited to 256 simultaneous colors, so they can’t achieve photographic quality.
PNG — Portable Network Graphics
You can think of PNG as the next-generation GIF. It’s a lossless image file format that supports transparency and millions of colors. It can also create animations, but few applications support this feature. PNGs are ideal for colorful illustrations and graphics.
TIFF — Tagged Image File Format
TIFF is the workhorse format for high-resolution printing, including art photography and other fine artwork. It’s a lossless image file format that retains extremely high photographic quality for scanning and printing. However, TIFF file sizes are usually huge, making them difficult to share for general purposes.
BMP — Bitmap
BMP is an uncompressed raster file format suited well for storing and displaying high-quality digital images. While you don’t need to worry about losing data with BMP files, BMPs generally have larger file sizes than other formats and can be difficult to store. BMPs are ideal for creating detailed scans or archival copies. This file format was originally developed by Microsoft for Windows, but it’s compatible with many different operating systems.
PDF — Portable Document Format.
PDF isn’t actually an image file format, but sometimes it can be a good idea to convert images into PDFs. You can open PDFs on any device and compress them to smaller file sizes without significantly affecting image quality. And, if you need to share multiple images at once, PDFs are a great option. You can convert your images into a single PDF document with online tools like Adobe Acrobat online services.
What are the best image file formats?
The best image file format will depend on your imagery needs and intended medium. To help you select the right fit, let’s zoom in on the best file formats for working with web images and lossless images, sending pictures, and printing.
Best web image formats.
Web images need to meet specific dimensions and requirements, displaying well across devices and monitors. The best web image formats include JPEG (or JPG), GIF, and PNG. All of these file types can be compressed and adjusted to fit your web needs.
JPEG is one of the most common web image formats, although you’ll want to keep an eye on the size and resolution to ensure your images display well. GIF loads quickly and is perfect for catching users’ attention on web pages with subtle animation or movement. Finally, PNG is a versatile option for your website, supporting up to 16 million colors and featuring transparency capabilities.
Best lossless image formats.
Lossless images can be compressed without losing unnecessary metadata or affecting the graphic appearance. The best lossless image formats include GIF, PNG, TIFF, and BMP. These file types can be edited or compressed without impacting your image quality, although they may have lower resolutions.
Best image formats to send pictures.
If you need to send pictures, the best image format to use will depend on your sharing method. JPEG (or JPG) is ideal for sending photos via email or the web. Phones today often save files using the High Efficiency Image Container (HEIC) format, although you can easily convert HEIC to JPEG using online tools. PDF is an excellent choice for sharing multiple images at the same time and can be sent via email or a cloud-sharing link.
Best image formats for printing.
The best image formats for printing include JPEG (or JPG), PDF, and TIFF. Based on your image resolution and file size, you’ll want to select a format that preserves the appearance and quality of your picture when printing. It looks best to print higher-resolution images, so you may need to adjust the resolution to work with your desired print dimensions.
How to choose the highest image quality format for your website.
To select the highest image quality format for your website, you should use consistent pixel dimensions and choose a format that matches your file size, color, and display needs.
JPEGs (or JPGs) work best for web photos, while PNGs might be a better choice for logos or simple graphics. GIFs are great for animations; however, they offer fewer color choices than PNGs.
Once you’ve selected the best format for your website, don’t forget to optimize your image by adjusting the dimensions and file size as needed and adding image alt text for accessibility and SEO (search engine optimization) keywords for searchability.
More resources to work with your files.
Now you’ve learned about file formats for images and when to use them, you might find these additional resources on formatting files helpful:
- Learn how to batch-convert JPG images on a Mac.
- Learn how to convert JPG to PDF on Windows 10.
- Learn how to extract images from a web page.
- Learn how to remove page numbers in Word.
- Learn how to read text from an image using OCR.
Explore everything you can do with Acrobat online services to convert, edit, and share your files.
