How to reduce a photo’s size in KB
- Choose the target size from the “Target size” menu — the form you are filling in usually states its limit.
- Select or drop the photo. The tool lowers the JPG quality step by step and, if needed, the dimensions, until the file fits.
- Download the result and check it looks right before uploading it.
KB, MB and why your photo is too big
A kilobyte (KB) is roughly a thousand bytes and a megabyte (MB) roughly a thousand kilobytes. Phone cameras save photos at very high resolution — often 12 megapixels or more — so a single picture is typically several megabytes. Upload forms set much lower limits to keep their systems fast, which is why a fresh photo is rejected.
Two ways a file gets smaller
- Lower quality: JPG discards detail the eye barely notices. Down to roughly 70% quality most photos look unchanged.
- Fewer pixels: halving the width and height cuts the pixel count to a quarter, which shrinks the file dramatically.
For very small targets the tool combines both. It always tells you when it had to reduce the dimensions to hit the size.
Which size should you choose?
Use the limit your form or site states. If it doesn’t state one, this is a reasonable starting point:
| Target | Typical use | What to expect |
|---|---|---|
| 10 KB | Signatures, tiny icons, very strict legacy forms | A few hundred pixels at most. Crop tightly; choose it from the Target size menu. |
| 20 KB | Signatures and small ID photos on application forms | All our test images fit, at 420–600 px wide. |
| 30 KB | Passport-style photos where 20 KB is too tight | Between the 20 KB and 50 KB results; pick it from the menu. |
| 50 KB | Face photos for registrations and portals | 700–1024 px wide in our test, depending on detail. |
| 100 KB | Job portals, CV photos, listings | Three of four test images kept their full width (up to 1600 px). |
| 200 KB | Email, documents, large website images | 1792–2560 px wide in our test. |
| 500 KB – 1 MB | Print-quality copies, sites with generous limits | Most photos keep near-full resolution. |
The pixel figures come from our own test of four images (three photos and a screenshot) on each size page, measured on 6 October 2026. Each size page shows the full table. The 10 KB, 30 KB and 500 KB to 1 MB rows are guidance only; we have not measured them.
Need it smaller than the menu allows?
Crop away background, then try again — cropping removes pixels without any loss of the part you care about. You can also use the full image compressor to set width and quality by hand, or remove hidden metadata first.