Changing quality of the JPEG when saving an image, changes the file size. For eg. I have the following image. Dimension: 243px x 53 px Quality:100% File Size:9.7kb Background:

sample image


If I edit the image, keeping the dimensions and Quality same, the file size still falls to 6.1kb.

sample 2

size 2

Problem: I am using Fotoresizer, which has a batch Quality change option, but due to the above problem, you cannot predict file size from quality alone. So when I batch change quality of a set of 200px x 300px images set at 20% quality, some files will turn out at 6kb, whereas others will turn out at 15kb, when the file size I want is 10kb.

Is there any program or programmable solution, which lets me save all files in a range of 10-11kb, without me manually changing the quality slider to change file size each time.


3 Answers 3


IDsizer will allow you to do this you can set a maximum file size from the interface and drop a batch of files to resize.


Just as an aside, be aware that the quality once you have done this may be quite poor. Also if the image will save at a high quality with out compression some files could be less than 10Kb.


Irfan View can convert image to jpeg of Your desired size.


If You will not find following option You have to download Irfan View plugins.

How to do it in Irfan View?

You have to press 'b' key or click on "file->batch conversion/rename". Then You can set desired file size of images You want to convert.

enter image description here


It might take longer to encode it. From what I tested it looks like that compression options are found by compressing image several times and doing binary search to find those which produce Your desired size; I may be wrong. :)


RIOT (Radical Image Optimization Tool) was the program I used for such a task. It's free for personal and non-profit usage and extremely easy to use. To batch-convert the images you press "Batch" button, add your images, choose "Additional tasks" -> "Compress to size" option, set desired filesize threshold and start the process. Of course, it takes somewhat longer comparing to the common conversion methods (for me, 7 images were converted in about 1 minute).

This is the screenshot of the tool in process.


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