A target is a ceiling, not an exact final size
When you enter 500KB, Kompixa tries to produce an output at or below that limit. A simple image may finish far below the ceiling, while a detailed image may require lower quality or smaller pixel dimensions.
1. Respect maximum dimensions
The image keeps its aspect ratio and is reduced only when it exceeds the selected width or height.
2. Search output quality
For JPEG and WebP, the browser encoder is tried at different quality levels to find the highest result that fits the limit.
3. Reduce dimensions if needed
If quality reduction alone is not enough, the workflow progressively reduces dimensions and repeats the quality search.
What affects the result?
- Pixel dimensions and amount of fine detail.
- Noise, texture, gradients and transparency.
- Selected output format and starting quality.
- Browser image-encoding implementation.
PNG is treated differently because the browser's PNG encoder does not use the same adjustable lossy quality control. For strict targets, JPEG or WebP is usually the practical output choice.