Image guide · Updated September 19, 2026
Compress an image to a file-size limit
A form asks for 200 KB, but your image is larger. Measure the result against the limit without quietly changing its dimensions.
Start with the receiving form
Check both its accepted formats and pixel dimensions. A 200 KB limit is not a 200-pixel limit. MallowDesk uses decimal units: 200 KB is 200,000 bytes. If another service uses KiB, 200 KiB is 204,800 bytes. A result at 200,000 bytes satisfies either of those size limits, but its format and dimensions still need to be accepted.
Set the limit before processing
In Output settings, turn on Find a result under a KB limit and enter the maximum. Choose a supported output format and your starting quality. Add your image, or use Apply settings to all for an existing batch. Each completed target result shows its exact output bytes, the requested limit, and the tested quality when the image was re-encoded with a lossy format.
What the search actually does
JPEG and WebP try at most five descending quality levels, starting at your selected quality. AVIF tries at most three because encoding can take longer. The tool returns the highest tested level that fits; it does not claim to find the highest possible quality. File size is measured after every attempt. A 20-second search budget stops additional attempts, and an external 60-second worker limit stops a stuck encode. Slow devices may therefore reach fewer candidates.
When the limit cannot be reached
An unsuccessful target is reported as Needs attention. No oversized candidate is silently marked complete or added to the batch ZIP. Increase the limit if the destination permits it. Otherwise choose a smaller percentage under Resize, or another accepted format, then apply again. PNG remains lossless; lowering the quality control does not throw away its colors. A PNG may need explicit resizing or conversion to meet a small limit.
Check the image, not only the number
Open Compare, inspect text and fine edges, then download and open the actual result. A tiny file with unreadable text is not a useful result. A portal may also reject dimensions, transparency, orientation, or unsupported formats. Keep the original and use the receiving service’s preview to confirm the upload.
Try it with a reproducible example
Open the source files, measured outputs, and settings. Use the same source for each comparison and inspect the actual result.