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Compress an image to between 40 KB and 120 KB
For a 40–120 KB requirement, aim for 40,960 to 120,000 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 461 × 345 up to 786 × 589 pixels.
40–120 KB
JPG · 40-120 KB (40,960-120,000 bytes) · original pixel size · white background
PixelFit aims between 40,960 and 120,000 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 40–120 KB
"At least 40 KB" is 40,000 or 40,960 bytes, so the safe minimum is 40,960. "At most 120 KB" is 120,000 or 122,880 bytes, so the safe maximum is 120,000. The window is 79,040 bytes wide, 66 % of the maximum: wide enough that, at quality 75, the largest 4:3 photo inside it has 2.9 times the pixels of the smallest.
If the best result under 120,000 bytes is below 40,960, PixelFit raises quality, then pads the file only if you opt in (below).
Pixel sizes that land between 40 KB and 120 KB
At quality 75, each kind of image lands in the 40–120 KB window from the first size up to the second.
| Image | Reaches 40 KB at | Stays under 120 KB up to |
|---|---|---|
| Head-and-shoulders portrait | 493 × 615 | 992 × 1,238 |
| Outdoor landscape (12 MP phone photo) | 461 × 345 | 786 × 589 |
| Scanned typed document page | 436 × 547 | 805 × 1,011 |
| Handwritten letter with signature | 811 × 666 | 1,504 × 1,236 |
| Flat-colour graphic (flag) | 1,364 × 954 | 3,085 × 2,159* |
Fixed pixel sizes against 40–120 KB
When the form fixes the pixels, the file lands in the 40,960–120,000 byte window between these two JPEG qualities; "pad" means even quality 95 stays under 40 KB.
| Pixel size | Lowest quality reaching 40 KB | Highest quality under 120 KB |
|---|---|---|
| 140 × 60 (small signature box) | none: pad 38,178 bytes | 95+ |
| 300 × 120 (signature strip) | none: pad 30,629 bytes | 95+ |
| 200 × 230 (small ID photo) | none: pad 18,537 bytes | 95+ |
| 413 × 531 (35 × 45 mm at 300 DPI) | 84 | 95+ |
| 600 × 600 (2 × 2 inch at 300 DPI) | 68 | 95+ |
| 800 × 600 (4:3 web photo) | any (30 reaches it) | 73 |
| 1200 × 1600 (3:4 portrait upload) | any (30 reaches it) | 56 |
What falls below 40 KB
Even at quality 95, the highest quality we measured (the tool also tries 100), a 4:3 photo stays under 40,960 bytes up to about 304 × 228 pixels (15 % of the pixels that still fit under 120 KB at quality 75); a handwritten page up to 441 × 362 and a portrait up to 286 × 357. From there to 461 × 345 a photo reaches 40 KB only above quality 75, and from 461 × 345 to 786 × 589 quality 75 lands inside 40–120 KB.
A 200 × 230 image (small ID photo) is about 21.9 KB at quality 95, so 45 % of a 40,960-byte file would be padding; a 140 × 60 image (small signature box) is about 2.7 KB at quality 95, so 93 % of a 40,960-byte file would be padding. Padding satisfies a file-size check of 40–120 KB and leaves the pixels unchanged; where the form does not fix the pixel size, a larger image is the cleaner way to reach 40 KB.
Upload sizes against 40–120 KB at quality 75
600 × 600 (about 45.5 KB) lands inside 40–120 KB as is. Below 40 KB: 200 × 230 (10.2 KB), which needs padding; 413 × 531 (31.2 KB), which reaches it from quality 84. Just above 120 KB: 800 × 600 (about 124,200 bytes), 1080 × 1080 (about 307,000 bytes), which need a lower quality or fewer pixels.
Inside 40–120 KB at quality 75, a handwritten page runs from 811 × 666 to 1,504 × 1,236 pixels and a portrait from 493 × 615 to 992 × 1,238.
How to compress an image to 40–120 KB
-
Open the tool above
Preset: minimum 40 KB, maximum 120 KB, JPG.
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Add the image
Drop, paste or pick it; the 40,960–120,000 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 40 KB).
-
Download
name-120kb.jpg; compare its byte count with 40–120 KB.
Forms that ask for 40–120 KB
Upload specs in our dataset with exactly this window. Verify with the official notice before you submit.
40–120 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 40 KB and 120 KB?
Use the tool on this page, preset to 40–120 KB: it returns a JPG of 40,960 to 120,000 bytes. A 4:3 photo stays under 120 KB up to about 786 × 589 at quality 75.
What if my image comes out smaller than 40 KB?
PixelFit raises the quality first, up to 100. A 200 × 230 image (small ID photo) is still only about 21.9 KB at quality 95, 18,537 bytes short of 40–120 KB, so it needs padding: opt in, and a JPEG comment segment adds the missing bytes without touching the picture.
Is a 78.6 KB file inside 40–120 KB?
Yes: anything from 40,960 to 120,000 bytes passes under both KB definitions. Exactly 122,880 bytes passes only where 1 KB = 1024 bytes.
Which pixel size lands between 40 KB and 120 KB?
At quality 75: a photo from about 461 × 345 to 786 × 589, a portrait from 493 × 615 to 992 × 1,238.
Related
Single limits
- Compress to 35 KB
- Compress to 40 KB Maximum only
- Compress to 45 KB
- Compress to 100 KB
- Compress to 120 KB Maximum only
- Compress to 150 KB
Pixel sizes under 120 KB
- 600×750 px digital passport photo about 114 KB as a quality-75 JPG
- 854×480 (FWVGA) about 104 KB as a quality-75 JPG
- 800×480 (WVGA) about 97.1 KB as a quality-75 JPG