The size, dimension and quality triangle
An image file's weight is roughly its pixel count multiplied by how many bytes each pixel costs, and that cost is set by format and quality. Fix the file size at 100 KB and the other two corners trade off against each other: a 1200-pixel-wide JPEG fits at genuinely good quality, a 2000-pixel version fits only at visibly rougher quality, and an 800-pixel version fits with quality to burn.
This tool automates the triangle. You fix the byte budget; it re-encodes on a canvas in a Web Worker, runs a binary search to find the highest quality that fits, and reduces dimensions only as a last resort. Switching output to WebP shifts the whole trade-off in your favour, since WebP spends bytes more efficiently than JPEG.
Where 100 KB pays off
Website and CMS uploads are the classic case: image weight dominates page load time, and a gallery of 100 KB photos loads several times faster than the same gallery at 3–5 MB phone-camera originals. Marketplace and classified listings often enforce per-image caps around this mark. Sharing works better too — an image already at 100 KB goes through WhatsApp or another messenger without the app applying its own aggressive recompression. Batch mode suits product galleries: compress the whole set to one target and download it as a ZIP, with each file's before and after size listed.
No upload, no queue
Because SafeFileConvert's entire pipeline runs in your browser, there is no waiting on a server and no copy of your product shots or personal photos held anywhere but your own machine. Files already under 100 KB come back untouched; everything else is re-encoded locally and handed straight back to you.