JPEG images can be saved with different amounts of compression.
Saving with "low-quality" compression slightly degrades image quality but
reduces file size from 25 to 12 kbytes and load time from 10 to 5 seconds.
(Low-quality JPEG compression: 1:32 compression. 12 Kbyte file)
The greater the compression, the smaller the file but the poorer the image quality.
(Lowest-quality JPEG compression: 1:45 compression. 8.7 Kbyte file)
Compare with the normal quality JPEG, 1:14 compression. 25 Kbyte file.
How to do it:
Graphic Converter (Macintosh): File --> Save As... --> Options --> Quality
Paint Shop Pro (Windows): File --> Save As... --> Options
--> Compression level.