Looking for consistency in jpg file size for use with website

[bluetiddlywinks]

I am looking to speed up the load times of my web pages and have noticed an inconsistency in the file sizes of the images. A good portion of the images are 150x125 with 72dpi resolution, however the file sizes range from 3kb to over 50kb. With the images all being the same dimensions and dpi, what causes this broad range of file size, and what steps can be taken to bring the large files down in size.

 

[Arch]

when you save as a jpeg, you get the quality slider..... this will determin the overall file size of the image.... if you notice.... when you move the jpeg quality from the max 12... down to say 9 (high) you can see at the bottom of the window the file size and the upload time in relation to connection speed.... use these figures to get all your images roughly the same.

If you really want to speed up loading times then you would have to lower the sizes to get a really quick upload speed.

 

[ksmattfish]

what causes this broad range of file size

Resolution, the amount of detail, colors, etc...

Take a photo where the frame is filled with a blank piece of white paper, and take a photo where the frame is filled with grass. The white paper photo file size will be significantly smaller.

 

[bluetiddlywinks]

In Photoshop how would one adjust the spectrum of color to reduce a file size? Are there any more advanced ways of reducing the overal quality other then just the slider bar at the very end when you save the file. I went to adjust the levels, pulling it in on both ends of the spectrum, but upon saving the file size had increased by ten.

 

[astrostu]

At least in the more recent versions of PhotoShop, there's a Save for the Web option that somehow compresses it even more, and you set the quality at a 0-100 scale.