When you license a video from iStock, you'll notice you can choose between different formats. Use the following guidelines to determine which is best for your project. • 4K | Good for maintaining high-quality output for TV, film, advertising, or large-scale displays. • HD | Most commonly used format. Gives a quality image relative to its file size. Good for TV, advertising, small digital projects, and social uses. Note: At times, you may see two HD options with different video codecs. Learn more about codecs • HD Web | Ideal for full screen web projects, online ads, and social projects. Good for streaming. Keep in mind that you can always re-download your video in any size—at no extra cost.