What actually fits in 100 KB
100 KB sounds tiny next to a 3–5 MB phone photo, but it's enough for a clear picture on a screen. The catch is that something has to give, and it's mostly pixels, not sharpness. Rough guide for JPG at decent quality:
| Image | What 100 KB typically holds |
|---|---|
| Ordinary photo (people, a room, a street) | about 1,000–1,300 px on the long side |
| Head-and-shoulders portrait on a plain background | 600 × 600 to 1,000 × 1,000 px with room to spare |
| Scanned A4 page or certificate | about 1,000–1,200 px wide; text stays readable |
| Screenshot with text, saved as JPG | roughly full-HD width, with slight halos round the letters |
| Detailed landscape (foliage, gravel, water) | closer to 800–1,000 px |
These are approximate — the content of the image matters more than anything else. A flat blue sky compresses to almost nothing; a field of grass eats bytes.
Where 100 KB limits show up
It's one of the most common caps on the web: photo fields in job and exam application forms, ID and profile uploads on registration portals, older webmail and forum attachments, support tickets. These forms usually display the picture small, so 1,000 px or so is more than they need.
How this page reaches 100 KB
- The target is 100,000 bytes — decimal kilobytes. That passes whether the site counts 1 KB as 1,000 or 1,024 bytes. The result shows sizes in 1,024-byte units, so a file right at the limit appears as about 98 KB. That's expected.
- It first looks for the highest JPG quality that fits (between 92% and 40%). If the photo is too big even at 40%, it reduces the width and height and tries again, rather than handing you a blocky mess.
- A JPG, PNG or WebP that is already under 100 KB is returned as it is, untouched.
- You can drop a batch; each file is handled separately and you get a ZIP.
Get a cleaner 100 KB file
The tool keeps as many pixels as it can, which on a 12-megapixel photo can mean a fairly low quality level. If the form will show the image small anyway, you often get a crisper result by making it smaller yourself first:
- Crop to what matters — just the face for a portrait, just the document for a scan. Use Crop Image.
- Resize to around 1,000–1,200 px on the long side with Resize Image, or set Max side in Compress Image with a 100 KB target.
- Then compress here. With fewer pixels the quality stays high.
Stick to JPG for photos. PNG is lossless and rarely gets a photo under 100 KB at a usable size.
"Between 20 KB and 100 KB"
Many forms give a range rather than a single maximum. This page aims just under the top value, so the result usually lands a little under 100 KB — inside the range. Two cases to watch:
- Your file is already below the minimum. It's returned unchanged, so it stays too small. Enlarge the pixel size with Resize Image (more pixels means more bytes), then check again.
- The form also asks for exact dimensions, such as 200 × 230 px. Resize to those dimensions first; at that size the photo will almost certainly be well under 100 KB at full quality.
When it still doesn't work
- The result stays PNG. Your image has transparent pixels (common for signatures and logos), so it's kept as PNG and only shrunk in size. If the form doesn't need transparency, convert it with PNG to JPG first.
- The form rejects the file type. A WebP stays WebP here; if the form wants JPG, use WebP to JPG. iPhone photos in HEIC go through HEIC to JPG.
- The limit is lower. Try 50 KB or 20 KB. If you have more room, 150 KB or 200 KB keep noticeably more detail.
Compression runs in your browser, so ID photos and scanned documents never leave your device.