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Compress an image to 12 KB
To get an image under 12 KB, PixelFit aims at 12,000 bytes or less, so forms counting 1 KB as 1000 or 1024 bytes both accept it. Estimated from our measured encodes, that is about 243 × 182 pixels for a 4:3 photo at quality 75, or 211 × 263 for a portrait.
Under 12 KB
JPG · under 12 KB (at most 12,000 bytes) · original pixel size · white background
PixelFit aims at 12,000 bytes or less, so the file passes whether the form counts 1 KB as 1,000 or 1,024 bytes.
Fit, background and padding white background
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.
What 12 KB means in bytes
12 KB is 12,288 bytes when 1 KB = 1024 bytes (12 × 1024) and 12,000 bytes when a server counts 1 KB = 1000 bytes. The 288-byte gap matters only near the limit. PixelFit aims at 12,000 bytes or less and prints the exact byte count, so you can compare it with the form.
12 KB is 0.012 MB; 853 such files fit in 10 MB. Uncompressed, the 243 × 182 photo that fits here would need 130 KB of raw pixels, so JPEG at quality 75 packs it about 11 to 1.
Largest pixel size that fits 12 KB
The biggest image of each kind, in its own aspect ratio, that stays at or below 12,000 bytes.
| Image | JPG q60 | JPG q75 | JPG q90 | WebP q75 |
|---|---|---|---|---|
| Head-and-shoulders portrait | 251 × 313 | 211 × 263 | 156 × 194 | 277 × 345 |
| Outdoor landscape (12 MP phone photo) | 281 × 210 | 243 × 182 | 187 × 140 | 261 × 195 |
| Scanned typed document page | 268 × 336 | 231 × 290 | 177 × 222 | 265 × 333 |
| Handwritten letter with signature | 471 × 387 | 390 × 320 | 282 × 231 | 594 × 488 |
| Flat-colour graphic (flag) | 607 × 424 | 511 × 357 | 364 × 254 | 789 × 552 |
A 12 MP phone photo at 12 KB
Our 12 MP landscape sample (4032 × 3024) is about 4.15 MB at quality 90, 363 times the 12 KB budget; even quality 30 leaves 1.26 MB (extrapolated from encodes up to 3,000 px). So the pixels must go down too.
At about quality 75 it fits 12 KB near 243 × 182 (0.04 MP, 0.36 % of the original pixels). Quality 60 allows 281 × 210; quality 90 needs 187 × 140.
JPEG quality for fixed pixel sizes under 12 KB
When a form fixes the pixels, only quality can move. Highest quality (of 100) that keeps each size at or under 12,000 bytes:
| Pixel size | Measured on | JPG | WebP |
|---|---|---|---|
| 140 × 60 (small signature box) | handwritten page | quality 95+ (2.7 KB) | quality 95+ (1.8 KB) |
| 300 × 120 (signature strip) | handwritten page | quality 95+ (10.1 KB) | quality 95+ (6.8 KB) |
| 200 × 230 (small ID photo) | portrait photo | quality 80 (11.4 KB) | quality 86 (11.2 KB) |
| 413 × 531 (35 × 45 mm at 300 DPI) | portrait photo | no: fewer pixels needed | quality 33 (11.6 KB) |
| 600 × 600 (2 × 2 inch at 300 DPI) | portrait photo | no: fewer pixels needed | no: fewer pixels needed |
| 800 × 600 (4:3 web photo) | landscape photo | no: fewer pixels needed | no: fewer pixels needed |
Measured JPEG files either side of 12 KB
Real encodes from our test set at quality 75: the largest file that stays under 12,000 bytes and the smallest that goes over.
| Image | Largest under 12 KB | Smallest over 12 KB |
|---|---|---|
| Head-and-shoulders portrait | 200 × 250: 11,139 B | 240 × 300: 14,229 B |
| Outdoor landscape (12 MP phone photo) | 200 × 150: 8,262 B | 250 × 188: 12,684 B |
| Scanned typed document page | 199 × 250: 8,926 B | 239 × 300: 12,810 B |
| Handwritten letter with signature | 300 × 247: 7,303 B | 400 × 329: 12,599 B |
| Flat-colour graphic (flag) | 500 × 350: 11,657 B | 600 × 420: 14,688 B |
JPG, WebP or PNG at 12 KB
At quality 75, WebP holds 261 × 195 of the landscape photo in 12 KB, JPG 243 × 182: 15 % more pixels. Portrait gain: 72 %. Typed page gain: 32 %. A moderate gain for the landscape photo at 12 KB, a large one for portraits: where WebP is accepted, use it for those. Many portals accept only JPG/JPEG, so this page starts in JPG.
A full-colour PNG is lossless, so its size follows the content. In 12 KB it holds a flat graphic of 318 × 222 pixels but a photo of only 85 × 63 (extrapolated), against 243 × 182 as a quality-75 JPG. Reducing a PNG to a palette of up to 256 colours (PixelFit does this when a PNG must shrink) helps graphics far more than photos.
Signatures and thumbnails under 12 KB
In our form dataset, 14 photo or signature limits are 20 KB or less: 12 for signatures, 2 for photos. Measured for 12 KB:
- A handwritten page fits at 390 × 320 at quality 75, so a cropped signature strip has room to spare.
- A typed page fits at 268 × 336 at quality 60: crop to the lines the form needs.
- A portrait fits at 211 × 263 at quality 75, a stamp-size photo.
- Cropping empty paper first leaves more of the 12,000 bytes for the strokes or the face.
How to compress an image to 12 KB
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Open the tool above
It is preset to 12 KB (12,000 bytes or less), JPG output.
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Add your image
Drop, paste or pick it; a PNG, WebP or (where the browser opens it) HEIC file becomes a JPG under 12 KB.
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Pixel size: only if asked
On auto, a typical photo stops near 243 × 182 at about quality 75.
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Download and check
name-12kb.jpg comes with its byte count, pixels and quality.
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 12 KB?
Drop it into the tool here, preset to 12 KB. It searches JPEG quality (at most 8 encodes per pixel size), then scales pixels down if needed, until the file is 12,000 bytes or less. A 4:3 photo typically lands near 243 × 182 at about quality 75.
How do I compress an image to less than 12 KB without losing quality?
Give up pixels before quality: at quality 75, 12 KB holds 243 × 182 of a photo and 211 × 263 of a portrait; quality 90 at 243 × 182 costs 64 % more bytes.
Is 12 KB 12,000 or 12,288 bytes?
Both readings exist: 12,288 bytes (1 KB = 1024) or 12,000 bytes (1 KB = 1000). 12,000 bytes or less passes both.
Can I compress a PNG to 12 KB?
Yes, but a full-colour PNG photo stays big: about 85 × 63 (extrapolated) pixels in 12 KB, versus 318 × 222 for a flat graphic. As a JPG the photo reaches 243 × 182.
Why does my signature look blurry at 12 KB?
Usually the scan is huge and gets scaled down hard. Crop tightly first: a handwritten page fits 12 KB at 390 × 320 at quality 75.
Related
Nearby file sizes
- Compress to 10 KB photo ≈ 221 × 165
- Compress to 5 KB photo ≈ 147 × 110
- Compress to 15 KB photo ≈ 273 × 204
- Compress to 16 KB photo ≈ 282 × 211
- Compress to 20 KB photo ≈ 317 × 237
More ways to hit 12 KB
- Image resizer with KB target Any size, pixels and format
Pixel sizes that fit 12 KB
- 200×200 minimum share image about 10.6 KB as a quality-75 JPG
- 192×192 PWA icon about 9.8 KB as a quality-75 JPG
- 180×180 apple-touch-icon about 8.7 KB as a quality-75 JPG
- 320×100 banner about 8.6 KB as a quality-75 JPG