Updated · how we check
Compress an image to 15 KB
To get an image under 15 KB, PixelFit aims at 15,000 bytes or less, so forms counting 1 KB as 1000 or 1024 bytes both accept it. Estimated from our measured encodes, that is about 273 × 204 pixels for a 4:3 photo at quality 75, or 249 × 310 for a portrait.
Under 15 KB
JPG · under 15 KB (at most 15,000 bytes) · original pixel size · white background
PixelFit aims at 15,000 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 15 KB means in bytes
15 KB is 15,360 bytes when 1 KB = 1024 bytes (15 × 1024) and 15,000 bytes when a server counts 1 KB = 1000 bytes. The 360-byte gap matters only near the limit. PixelFit aims at 15,000 bytes or less and prints the exact byte count, so you can compare it with the form.
15 KB is 0.015 MB; 682 such files fit in 10 MB. Uncompressed, the 273 × 204 photo that fits here would need 163 KB of raw pixels, so JPEG at quality 75 packs it about 11 to 1.
Largest pixel size that fits 15 KB
The biggest image of each kind, in its own aspect ratio, that stays at or below 15,000 bytes.
| Image | JPG q60 | JPG q75 | JPG q90 | WebP q75 |
|---|---|---|---|---|
| Head-and-shoulders portrait | 294 × 367 | 249 × 310 | 180 × 224 | 333 × 415 |
| Outdoor landscape (12 MP phone photo) | 316 × 237 | 273 × 204 | 211 × 158 | 294 × 220 |
| Scanned typed document page | 301 × 378 | 259 × 325 | 198 × 248 | 299 × 375 |
| Handwritten letter with signature | 539 × 443 | 446 × 366 | 318 × 261 | 684 × 562 |
| Flat-colour graphic (flag) | 727 × 508 | 610 × 427 | 438 × 306 | 960 × 672 |
A 12 MP phone photo at 15 KB
Our 12 MP landscape sample (4032 × 3024) is about 4.15 MB at quality 90, 290 times the 15 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 15 KB near 273 × 204 (0.06 MP, 0.46 % of the original pixels). Quality 60 allows 316 × 237; quality 90 needs 211 × 158.
JPEG quality for fixed pixel sizes under 15 KB
When a form fixes the pixels, only quality can move. Highest quality (of 100) that keeps each size at or under 15,000 bytes:
| Pixel size | Measured on | JPG | WebP |
|---|---|---|---|
| 300 × 120 (signature strip) | handwritten page | quality 95+ (10.1 KB) | quality 95+ (6.8 KB) |
| 200 × 230 (small ID photo) | portrait photo | quality 87 (14.2 KB) | quality 91 (14.2 KB) |
| 413 × 531 (35 × 45 mm at 300 DPI) | portrait photo | no: fewer pixels needed | quality 50 (14.5 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 |
| 1200 × 1600 (3:4 portrait upload) | portrait photo | no: fewer pixels needed | no: fewer pixels needed |
Measured JPEG files either side of 15 KB
Real encodes from our test set at quality 75: the largest file that stays under 15,000 bytes and the smallest that goes over.
| Image | Largest under 15 KB | Smallest over 15 KB |
|---|---|---|
| Head-and-shoulders portrait | 240 × 300: 14,229 B | 320 × 400: 21,568 B |
| Outdoor landscape (12 MP phone photo) | 250 × 188: 12,684 B | 300 × 225: 18,059 B |
| Scanned typed document page | 239 × 300: 12,810 B | 318 × 400: 22,368 B |
| Handwritten letter with signature | 400 × 329: 12,599 B | 500 × 411: 18,061 B |
| Flat-colour graphic (flag) | 600 × 420: 14,688 B | 800 × 560: 20,958 B |
JPG, WebP or PNG at 15 KB
At quality 75, WebP holds 294 × 220 of the landscape photo in 15 KB, JPG 273 × 204: 16 % more pixels. Portrait gain: 79 %. Typed page gain: 33 %. A moderate gain for the landscape photo at 15 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 15 KB it holds a flat graphic of 382 × 267 pixels but a photo of only 96 × 72 (extrapolated), against 273 × 204 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 15 KB
In our form dataset, 14 photo or signature limits are 20 KB or less: 12 for signatures, 2 for photos. Measured for 15 KB:
- A handwritten page fits at 446 × 366 at quality 75, so a cropped signature strip has room to spare.
- A typed page fits at 301 × 378 at quality 60: crop to the lines the form needs.
- A portrait fits at 249 × 310 at quality 75, a stamp-size photo.
- Cropping empty paper first leaves more of the 15,000 bytes for the strokes or the face.
How to compress an image to 15 KB
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Open the tool above
It is preset to 15 KB (15,000 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 15 KB.
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Pixel size: only if asked
On auto, a typical photo stops near 273 × 204 at about quality 75.
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Download and check
name-15kb.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 15 KB?
Drop it into the tool here, preset to 15 KB. It searches JPEG quality (at most 8 encodes per pixel size), then scales pixels down if needed, until the file is 15,000 bytes or less. A 4:3 photo typically lands near 273 × 204 at about quality 75.
How do I compress an image to less than 15 KB without losing quality?
Give up pixels before quality: at quality 75, 15 KB holds 273 × 204 of a photo and 249 × 310 of a portrait; quality 90 at 273 × 204 costs 64 % more bytes.
Is 15 KB 15,000 or 15,360 bytes?
Both readings exist: 15,360 bytes (1 KB = 1024) or 15,000 bytes (1 KB = 1000). 15,000 bytes or less passes both.
Can I compress a PNG to 15 KB?
Yes, but a full-colour PNG photo stays big: about 96 × 72 (extrapolated) pixels in 15 KB, versus 382 × 267 for a flat graphic. As a JPG the photo reaches 273 × 204.
Why does my signature look blurry at 15 KB?
Usually the scan is huge and gets scaled down hard. Crop tightly first: a handwritten page fits 15 KB at 446 × 366 at quality 75.
Related
Nearby file sizes
- Compress to 12 KB photo ≈ 243 × 182
- Compress to 10 KB photo ≈ 221 × 165
- Compress to 5 KB photo ≈ 147 × 110
- Compress to 16 KB photo ≈ 282 × 211
- Compress to 20 KB photo ≈ 317 × 237
- Compress to 25 KB photo ≈ 357 × 267
More ways to hit 15 KB
- Image resizer with KB target Any size, pixels and format
Pixel sizes that fit 15 KB
- 200×230 px photo about 12.1 KB as a quality-75 JPG
- 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