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JPG to PDF under 30 KB
To make a PDF under 30 KB, PixelFit compresses the JPG to at most 29,264 bytes and wraps it in a one-page PDF with about 736 bytes of PDF structure, 30,000 bytes or less in total. Measured: an A4 scan fits up to 51 DPI at quality 50; a 4:3 photo at about 389 × 291 pixels (quality 75).
PDF under 30 KB
PDF · under 30 KB (at most 30,000 bytes) · original pixel size · white background
PixelFit aims at 30,000 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 · page the size of the picture
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.
Where the 30 KB go in a JPG-to-PDF file
Of the 30,000 bytes that pass as 30 KB under both KB definitions, PDF structure takes 736 bytes for one A4 page (computed with PixelFit's own writer), leaving 29,264 bytes, 97.5 %, for the JPEG; ten pages leave 2,476 bytes each.
For one photo, quality 75 allows 389 × 291 pixels and quality 90 299 × 224; a full 12 MP frame must be scaled down first, which the tool does for you.
How many pages fit in a 30 KB PDF
The 30,000 bytes of 30 KB, less 736 bytes of PDF structure for the first page and about 500 for each extra one, shared evenly.
| Pages | JPEG bytes per page | Max A4 DPI at q50 | Max A4 DPI at q75 | A4 at 150 DPI |
|---|---|---|---|---|
| 1 page | 29,264 | 51 DPI | 41 DPI | no: 4.3× over at q30 |
| 2 pages | 14,384 | 36 DPI | 28 DPI | no: 8.7× over at q30 |
| 3 pages | 9,422 | 29 DPI | 23 DPI | no: 13.3× over at q30 |
| 5 pages | 5,453 | 22 DPI | 17 DPI | no: 23.0× over at q30 |
Phone photos in one PDF under 30 KB
Largest 4:3 photo per page, in pixels, when 1 to 10 photos share 30,000 bytes; "full" means a 12 MP phone photo keeps all its pixels (the tool never enlarges).
| Photos | Quality 60 | Quality 75 | Quality 90 |
|---|---|---|---|
| 1 photo | 451 × 338 | 389 × 291 | 299 × 224 |
| 2 photos | 309 × 231 | 267 × 200 | 206 × 154 |
| 3 photos | 248 × 186 | 214 × 160 | 163 × 122 |
| 5 photos | 183 × 137 | 155 × 116 | 119 × 89 |
A4 and Letter pixel sizes against 30 KB
One typed page per DPI: its pixels, the quality it gets alone in 30 KB, and how many fit at quality 75.
| DPI | A4 pixels | One A4 page under 30 KB | Letter page | Pages at q75 |
|---|---|---|---|---|
| 72 DPI | 595 × 842 | no: 1.3× over at q30 | no: 1.3× over at q30 | none |
| 100 DPI | 827 × 1169 | no: 2.3× over at q30 | no: 2.2× over at q30 | none |
| 150 DPI | 1240 × 1754 | no: 4.3× over at q30 | no: 4.2× over at q30 | none |
| 200 DPI | 1654 × 2339 | no: 6.4× over at q30 | no: 6.3× over at q30 | none |
| 300 DPI | 2480 × 3508 | no: 11.6× over at q30 | no: 11.3× over at q30 | none |
Readable pages and photos in 30 KB
30 KB holds a full typed A4 page only as a low-resolution scan: about 51 DPI (422 × 596 pixels) at quality 50, where a line of 12-point type is about 9 pixels tall, hard to read. A 72 DPI scan (595 × 842) is 1.3 times too big even at quality 30.
What fits at a readable 150 DPI is a crop: a full-width strip about 36 mm high (12 % of the page, roughly 7 lines of 12-point type at single spacing) at quality 50. For a certificate or mark sheet, crop to the part the form needs before you convert.
Under 30 KB a full 150 DPI A4 scan gets nothing: even quality 30 is 4.3 times too big, and no photo of 1600 × 1200 fits at quality 70.
One image free, several merged with Pro
Free: each image becomes its own one-page PDF under 30 KB. Pro: several images merged into one PDF under 30 KB, on your device; 2 pages get 14,384 bytes of JPEG each.
How to turn a JPG into a PDF under 30 KB
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Open the tool above
Preset: PDF output, at most 30 KB.
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Add the JPG
Drop, paste or pick it (PNG, WebP and HEIC work too).
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Choose the page
Keep the picture's own size or fit it on A4 or Letter.
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Download
name-30kb.pdf arrives with its exact byte count (30,000 bytes or less).
Sources
- Measured by PixelFit with sharp 0.35.5 / libvips 8.18.7 on 31 October 2026.
- Samples, Wikimedia Commons, checked 31 October 2026: typed page (public domain) commons.wikimedia.org/w/index.php?curid=194775753; landscape (CC0 1.0) commons.wikimedia.org/w/index.php?curid=154070378
- Paper sizes, Markus Kuhn, checked 31 October 2026: cl.cam.ac.uk/~mgk25/iso-paper.html
- PDF format, Library of Congress, checked 31 October 2026: loc.gov/preservation/digital/formats/fdd/fdd000474.shtml
Frequently asked questions
How do I convert a JPG to PDF under 30 KB?
Drop the JPG into the tool on this page, preset to PDF under 30 KB: the picture is compressed to 29,264 bytes or less, so the PDF ends at or below 30,000 bytes.
Can I convert JPG to PDF for free?
Yes, one image per PDF, with no upload. Under 30 KB a 4:3 photo keeps 389 × 291 pixels at quality 75; merging several JPGs is Pro.
How many pages fit in a 30 KB PDF?
Under 30 KB, not even one full A4 page at 150 DPI keeps quality 50; a whole page fits only at about 51 DPI, so crop to the part you need (a full-width strip about 36 mm high at 150 DPI).
What DPI should a scan have for a 30 KB PDF?
None of the usual 72 to 300 DPI settings keeps a full A4 page at quality 50 under 30 KB: the limit is about 51 DPI. Scan at 150 DPI and crop to the needed part instead.
Why is the PDF bigger than my JPG?
A PDF wraps the JPEG in page, image and cross-reference objects: 736 bytes for one page in PixelFit's writer, about 500 more per added page.
Related
Other PDF size limits
- JPG to PDF under 20 KB one cropped image
- JPG to PDF under 40 KB one cropped image
- JPG to PDF under 50 KB one cropped image
- JPG to PDF under 100 KB one cropped image
More for 30 KB
- Compress an image to 30 KB Same limit, image output
- JPG to PDF: what changes Format facts
- Image resizer with KB target Any size and format
Other formats to PDF
Pixel sizes that fit 30 KB
- 160×600 banner about 24.5 KB as a quality-75 JPG
- 336×280 banner about 24 KB as a quality-75 JPG
- 300×300 square about 23.1 KB as a quality-75 JPG