This web-app encodes 24-bit bitmaps to baseline sequential JPEGs as specified in ITU T.81. Select one of the three sample images using the drop-down below and move the quality slider to see the effect on filesize, compression ratio and perceptible image quality. Alternatively, try uploading your own bitmaps, though be warned that only 24-bit colour bitmaps are supported. Other types of bitmap may successfully load, but will not be processed properly.
To prove that this isn't just smoke and mirrors, you can download the resulting JPEG (which will be named 'out.jpg') for viewing in a photo editor of your choice. I have had no issues opening these in both Windows photo viewer and Paint.NET, though I would be interested to hear if you face any problems with this.
Full description at: https://github.com/wjgra/jpeg-encoder.
