The most effective method to compress an image in Unity is by using Crunch Compression, as indicated in the following image:

For image Texture Type " Sprite (2D and UI), " you need to make each image resolution like " 256x64, 256x128, 512x256, 1024x512, 2048x1024" like this example image with resolution 256x64 with size 6.4 KB:

If the resolution image is 252x64 will  have 84.0 KB and look like this:

Imagine having numerous images with incorrect resolutions, leading to a substantial challenge in creating mobile browsers or WebGL games. Alternatively, use the tutorial above and enjoy your awesome game :)).

Image optimization is critical in developing high-performance Unity-engaging user experiences. A lack of proper optimization can compromise game performance, particularly on low-end hardware. Here are a few strategies to optimize image assets in your Unity game projects.

Firstly, the target platform should always be at the forefront of your consideration. The demands of a high-end PC game will differ significantly from those of a mobile game. Unity provides many settings to control compression levels and texture size constraints according to the intended platformAdjustingst these settings to align with the device's capabilities is crucial s to prevent overwhelming your target device with oversized textures.

The following measure involves utilizing appropriate image formats. Your specific requirements may lead you to choose from PNG for its lossless compression, JPG for its lossy compression, or more unique forms like ETC1 designed for mobile devices. Unity is compatible with various forms, each presenting its advantages and disadvantages. By gaining a solid understanding of these, you can ensure the selection of the most suitable design for each asset.