A 100KB limit is common for uploads, profile images and performance budgets. Treat it as an approximate ceiling rather than a promise of identical quality: a detailed photo needs different settings from a flat illustration.
1. Resize before compressing
Find the largest width the image needs in its final layout. A 1,200-pixel-wide image is often enough for a content column, while a small thumbnail may need only 400 pixels. Fewer pixels give the encoder less information to store.
2. Pick the format
For photographs, try WebP or JPG. WebP often reaches 100KB with more detail, while JPG is a dependable fallback. Use PNG for crisp, limited-color graphics or transparency, but expect photographs to be larger.
3. Tune quality gradually
Start around 80 percent quality and inspect the output. Lower it in small steps, checking text, faces and high-contrast edges. If quality becomes unacceptable, reduce dimensions slightly instead of aggressively degrading the whole image.
Important: 100KB means 100 kilobytes, or roughly 102,400 bytes. Encoders cannot guarantee an exact byte count, so leave a small margin when a platform enforces a hard maximum.
4. Verify the actual result
File extensions are not measurements. Open the downloaded file and check its real size, dimensions and format. A browser-based compressor can show these values before you publish.
OptmizeImage has a dedicated 100KB tool that sends you to the target-size workflow without uploading the image.
Open the 100KB optimizer →