How the target size is reached
The tool searches for the highest quality setting that still fits inside 100 KB. It encodes the image, measures the result, and adjusts the quality up or down; this repeats a few times until the closest match is found. If even the lowest reasonable quality is still too large, the image is progressively scaled down as well, and the final dimensions are reported with the result.
When a target cannot be met
Some images simply cannot fit a small limit while staying usable — a very large photograph forced under a tight budget, for example. In that case the tool shows the smallest file it managed to produce together with a clear notice, instead of silently returning something that does not meet the limit.
Getting a better result
- Resize before compressing when the image is much larger than it needs to be. Fewer pixels means the quality setting can stay high.
- Choose WebP when the destination accepts it: the same limit then allows a noticeably better looking image.
- Crop away empty margins. Less area to encode leaves more room for the part that matters.
Where size limits come from
Upload limits of 100 KB are common on government and university application portals, job boards, forums and content management systems. The limit is applied to the stored file, which is why the reported size after compression is the number that counts.