Optimizing images for the JPEG format (2024)

TheJPEG format supports 24‑bit color, so it preserves the subtle variationsin brightness and hue found in photographs. A progressive JPEG filedisplays a low-resolution version of the image in the web browserwhile the full image is downloading.

JPEG image compression is called lossy because it selectivelydiscards image data. A higher quality setting results in less databeing discarded, but the JPEG compression method may still degradesharp detail in an image, particularly in images containing typeor vector art.

Note:

Artifacts, such as wavelike patterns or blocky areas of banding,are created each time you save an image in JPEG format. Therefore,you should always save JPEG files from the original image, not froma previously saved JPEG.

1. Open an image and choose File> SaveFor Web.

2. Choose JPEG from the optimization format menu.

   See Also

   15 Best Image File Types (Pros vs Cons + Use Cases for Each Format)

3. To optimize to a specific file size, click the arrowto the right of the Preset menu, and then click Optimize To FileSize. Enter a number in the Desired File Size text box, and selecteither Current Settings, which optimizes for the current settings,or Auto Select GIF/JPEG, which automatically determines whether JPEGor GIF is the better format.

4. Do one of the following to specify the compression level:

   • Choose a quality option (Low, Medium, High,and so on) from the pop‑up menu under the optimization format menu.

   • Click the arrow in the Quality menu and drag theQuality pop‑up slider.

   • Enter a value between 0 and 100 in the Quality box.

     Thehigher the Quality setting, the more detail is preserved in theoptimized image, but the larger the file size. View the optimizedimage at several quality settings to determine the best balancebetween quality and file size.

5. Select Progressive to display the image progressivelyin a web browser; that is, to display it first at a low resolution,and then at progressively higher resolutions as downloading proceeds.

   Note:

   Some browsers do not support progressive JPEGs.

6. To preserve the ICC profile of the original image inthe optimized file, select ICC Profile.

   Some browsers use ICC profiles for color correction. TheICC profile of the image depends on your current color setting.

7. If the original image contains transparency, select aMatte color that matches the background of your web page. Transparentareas in your original image are filled with the Matte color.

8. To save your optimized image, click OK. In the Save OptimizedAs dialog box, type a filename, and click Save.

More like this

• Create a matted GIF or PNG image
• About color management