Updated · how we check
Compress an image to between 10 KB and 50 KB
For a 10–50 KB requirement, aim for 10,240 to 50,000 bytes: that window passes whether the form counts 1 KB as 1000 or 1024 bytes. At quality 75 a 4:3 photo lands inside it from about 223 × 167 up to 510 × 382 pixels.
10–50 KB
JPG · 10-50 KB (10,240-50,000 bytes) · original pixel size · white background
PixelFit aims between 10,240 and 50,000 bytes, so the file passes whether the form counts 1 KB as 1,000 or 1,024 bytes.
Fit, background and padding white background · padding off
Saving presets is part of Pro.
The result appears here: the exact byte count, pixel size and quality, the size before and after, a preview and a download button.
The batch kit (one ZIP for up to 500 photos, several photos merged into one PDF) is part of Pro.
The safe byte window for 10–50 KB
"At least 10 KB" is 10,000 or 10,240 bytes, so the safe minimum is 10,240. "At most 50 KB" is 50,000 or 51,200 bytes, so the safe maximum is 50,000. The window is 39,760 bytes wide, 80 % of the maximum: wide enough that, at quality 75, the largest 4:3 photo inside it has 5.2 times the pixels of the smallest.
If the best result under 50,000 bytes is below 10,240, PixelFit raises quality, then pads the file only if you opt in (below).
Pixel sizes that land between 10 KB and 50 KB
At quality 75, each kind of image lands in the 10–50 KB window from the first size up to the second.
| Image | Reaches 10 KB at | Stays under 50 KB up to |
|---|---|---|
| Head-and-shoulders portrait | 189 × 236 | 562 × 701 |
| Outdoor landscape (12 MP phone photo) | 223 × 167 | 510 × 382 |
| Scanned typed document page | 213 × 267 | 485 × 609 |
| Handwritten letter with signature | 358 × 294 | 906 × 744 |
| Flat-colour graphic (flag) | 448 × 313 | 1,601 × 1,120 |
Fixed pixel sizes against 10–50 KB
When the form fixes the pixels, the file lands in the 10,240–50,000 byte window between these two JPEG qualities; "pad" means even quality 95 stays under 10 KB.
| Pixel size | Lowest quality reaching 10 KB | Highest quality under 50 KB |
|---|---|---|
| 140 × 60 (small signature box) | none: pad 7,458 bytes | 95+ |
| 300 × 120 (signature strip) | 95 | 95+ |
| 200 × 230 (small ID photo) | 74 | 95+ |
| 413 × 531 (35 × 45 mm at 300 DPI) | any (30 reaches it) | 88 |
| 600 × 600 (2 × 2 inch at 300 DPI) | any (30 reaches it) | 77 |
What falls below 10 KB
Even at quality 95, the highest quality we measured (the tool also tries 100), a 4:3 photo stays under 10,240 bytes up to about 145 × 108 pixels (8 % of the pixels that still fit under 50 KB at quality 75); a handwritten page up to 208 × 171 and a portrait up to 114 × 142. From there to 223 × 167 a photo reaches 10 KB only above quality 75, and from 223 × 167 to 510 × 382 quality 75 lands inside 10–50 KB.
A 140 × 60 image (small signature box) is about 2.7 KB at quality 95, so 73 % of a 10,240-byte file would be padding. Padding satisfies a file-size check of 10–50 KB and leaves the pixels unchanged; where the form does not fix the pixel size, a larger image is the cleaner way to reach 10 KB.
Upload sizes against 10–50 KB at quality 75
200 × 230 (about 10.2 KB), 413 × 531 (about 31.2 KB), 600 × 600 (about 45.5 KB) land inside 10–50 KB as is. Below 10 KB: 140 × 60 (1.1 KB), which needs padding; 300 × 120 (3.8 KB), which reaches it from quality 95. Just above 50 KB: 800 × 600 (about 124,200 bytes), 1080 × 1080 (about 307,000 bytes), which need a lower quality or fewer pixels.
Inside 10–50 KB at quality 75, a handwritten page runs from 358 × 294 to 906 × 744 pixels and a portrait from 189 × 236 to 562 × 701.
How to compress an image to 10–50 KB
-
Open the tool above
Preset: minimum 10 KB, maximum 50 KB, JPG.
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Add the image
Drop, paste or pick it; the 10,240–50,000 byte window is applied for you.
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Fix pixels only if required
With pixels fixed, only quality moves (and padding, if you allow it, to reach 10 KB).
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Download
name-50kb.jpg; compare its byte count with 10–50 KB.
Forms that ask for 10–50 KB
Upload specs in our dataset with exactly this window. Verify with the official notice before you submit.
10–50 KB
Sources
- Measured by PixelFit with sharp 0.35.5 / libvips 8.18.7 on 31 October 2026.
- Sample images, Wikimedia Commons, checked 31 October 2026: landscape (CC0 1.0) commons.wikimedia.org/w/index.php?curid=154070378; portrait commons.wikimedia.org/w/index.php?curid=23956389; typed page commons.wikimedia.org/w/index.php?curid=194775753; handwritten letter commons.wikimedia.org/w/index.php?curid=90423615; flag commons.wikimedia.org/w/index.php?curid=361734 (public domain).
- Binary prefixes, NIST, checked 31 October 2026: physics.nist.gov/cuu/Units/binary.html
Frequently asked questions
How do I compress an image to between 10 KB and 50 KB?
Use the tool on this page, preset to 10–50 KB: it returns a JPG of 10,240 to 50,000 bytes. A 4:3 photo stays under 50 KB up to about 510 × 382 at quality 75.
What if my image comes out smaller than 10 KB?
PixelFit raises the quality first, up to 100. A 140 × 60 image (small signature box) is still only about 2.7 KB at quality 95, 7,458 bytes short of 10–50 KB, so it needs padding: opt in, and a JPEG comment segment adds the missing bytes without touching the picture.
Is a 29.4 KB file inside 10–50 KB?
Yes: anything from 10,240 to 50,000 bytes passes under both KB definitions. Exactly 51,200 bytes passes only where 1 KB = 1024 bytes.
Which pixel size lands between 10 KB and 50 KB?
At quality 75: a photo from about 223 × 167 to 510 × 382, a portrait from 189 × 236 to 562 × 701.
Related
Single limits
- Compress to 5 KB
- Compress to 10 KB Maximum only
- Compress to 12 KB
- Compress to 45 KB
- Compress to 50 KB Maximum only
- Compress to 60 KB
Ranges sharing a limit
Pixel sizes under 50 KB
- 600×315 link preview image about 47.3 KB as a quality-75 JPG
- 300×600 banner about 45.1 KB as a quality-75 JPG
- 35×35 mm photo about 42.7 KB as a quality-75 JPG