Why is my compressed image larger than the original?

Running an image through a compressor does not guarantee a smaller file. DeskKit compares the output bytes with the source and tells you when the result is larger. That is useful feedback: it prevents a larger export from being mistaken for a successful reduction.

The original may already be efficient

A source image might have been encoded with lower quality, smaller dimensions or a different encoder. Exporting it again at 80% quality can produce more bytes. The number on one quality slider is not a universal measure shared by every image encoder.

The output format may be a poor fit

A photograph converted to PNG can grow considerably because the output is lossless. Conversely, a screenshot with flat colours may behave differently from a detailed photograph at the same dimensions. Compare the actual result, rather than assuming one extension always wins.

Check the dimensions

Accidentally increasing the width or height creates a larger pixel canvas. Keep the aspect ratio enabled and verify that the output is no larger than you intended. If you only need a small web preview, exporting the original camera dimensions may be unnecessary.

A practical recovery sequence

Return to the original file rather than compressing the latest export again.
Choose an output format accepted by your destination.
Reduce dimensions if the destination allows it.
For JPEG or WebP, try a lower quality setting.
Create another preview, compare sizes and inspect the image.

Know when to keep the original

If the original already meets the upload rules and looks better, keep it. Saving a new file is not a goal by itself. When tiny text or important details become unreadable, further compression may do more harm than a small byte reduction is worth. Store both versions with clear names so you do not overwrite your useful source.

A DeskKit test example

During a browser check, a 1536 × 1536 JPEG logo image went from about 263 KB to 190 KB at the selected settings, a reduction of roughly 27.6%. This is one measured example, not a promise for other files. The content of your image and your browser’s encoder affect the outcome.