How the KB target works
- The image is first resized to any dimensions you set.
- It is encoded at the lowest acceptable quality. If even that is too big and you allow it, the dimensions are reduced in proportion to how far off the size is, and it tries again.
- Once a version fits, Kilomill searches between “fits” and “too big” for the highest quality under your limit, usually in 3–6 encodes.
- If the form also has a minimum, the quality is raised, and as a last resort a comment block pads the JPG file up to the minimum.
Kilomill counts your maximum as 1,000 bytes per KB, which is the stricter reading. A file that passes “100 KB” here is at most 100,000 bytes, so it passes forms that count 1,024 bytes per KB too.
Presets for common limits
| Limit | Often asked for |
|---|---|
| 20 KB | Signatures and small photos on application portals |
| 50 KB | Passport-size photos on exam and job application forms |
| 20–50 KB | Forms with a minimum and a maximum, such as IBPS photos |
| 100 KB | Photos and scanned documents on government and university portals |
| 200 KB | Visa photos, larger document scans |
| 1 MB | Upload forms, email attachments, marketplaces |
Many forms have a minimum too
Size rules are often ranges, not just maximums: the UK online passport photo must be at least 50 KB, IBPS asks for a photo of 20–50 KB, and UPSC’s ESE 2027 notice wants each image between 20 KB and 300 KB (all read 21 Oct 2026). Enter both numbers and Kilomill keeps the file inside the range.
Get the best quality for a tight limit
- Crop first. Every pixel you remove (empty background, borders) leaves more bytes for the face or text that matters. Use Crop & rotate on the image.
- Set the dimensions the form asks for. If a form says 200 × 230 pixels, use exactly that: a bigger image wastes bytes, a smaller one may be rejected.
- Keep JPG. PNG is the wrong format for photos under a size limit; it needs far more bytes.
- Plain backgrounds compress better. A light, even background takes far fewer bytes than a busy one.