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PixelFit

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JPG to PDF under 3 MB

To make a PDF under 3 MB, PixelFit compresses the JPG to at most 2,999,260 bytes and wraps it in a one-page PDF with about 740 bytes of PDF structure, 3,000,000 bytes or less in total. Measured: an A4 scan at 150 DPI fits at quality 95; a 4:3 photo at about 4,314 × 3,235 (extrapolated) pixels (quality 75).

PDF under 3 MB

PDF · under 3 MB (at most 3,000,000 bytes) · original pixel size · white background

PixelFit aims at 3,000,000 bytes or less, so the file passes whether the form counts 1 MB as 1,000,000 or 1,048,576 bytes.

Fit, background and padding white background · page the size of the picture

Saving presets is part of Pro.

Pick a photo to fit it to under 3 MB (at most 3,000,000 bytes).

The result appears here: the exact byte count, pixel size and quality, the size before and after, a preview and a download button.

Where the 3 MB go in a JPG-to-PDF file

Of the 3,000,000 bytes that pass as 3 MB whether a megabyte is 1,000,000 or 1,048,576 bytes, PDF structure takes 740 bytes for one A4 page (computed with PixelFit's own writer), leaving 2,999,260 bytes, 99.9 %, for the JPEG; ten pages leave 299,473 bytes each.

For one photo that is plenty: a full 12 MP phone photo fits at quality 79 (extrapolated). The limit matters when many pages share it.

How many pages fit in a 3 MB PDF

The 3,000,000 bytes of 3 MB, less 740 bytes of PDF structure for the first page and about 502 for each extra one, shared evenly.

* = extrapolated beyond our scans (3000 px long edge, 256 DPI on A4).
PagesJPEG bytes per pageMax A4 DPI at q50Max A4 DPI at q75A4 at 150 DPI
1 page 2,999,260 600 DPI or more* 600 DPI or more* quality 95+
2 pages 1,499,381 600 DPI or more* 450 DPI* quality 95+
3 pages 999,419 487 DPI* 350 DPI* quality 95+
5 pages 599,451 349 DPI* 254 DPI quality 93
10 pages 299,473 222 DPI 165 DPI quality 80
20 pages 149,485 138 DPI 105 DPI quality 41
50 pages 59,491 77 DPI 60 DPI no: 2.1× over at q30
100 pages 29,491 52 DPI 41 DPI no: 4.2× over at q30

Make a PDF under 3 MB →

Phone photos in one PDF under 3 MB

Largest 4:3 photo per page, in pixels, when 1 to 10 photos share 3,000,000 bytes; "full" means a 12 MP phone photo keeps all its pixels (the tool never enlarges).

Width × height in pixels. * = outside the measured range (100 to 3000 px long edge), extrapolated.
PhotosQuality 60Quality 75Quality 90
1 photo full 4032 × 3024* full 4032 × 3024* 3,278 × 2,458*
2 photos 3,395 × 2,546* 2,917 × 2,187 2,235 × 1,676
3 photos 2,703 × 2,027 2,322 × 1,741 1,801 × 1,350
5 photos 2,038 × 1,528 1,763 × 1,322 1,382 × 1,036
10 photos 1,423 × 1,067 1,231 × 923 978 × 733

A4 and Letter pixel sizes against 3 MB

One typed page per DPI: its pixels, the quality it gets alone in 3 MB, and how many fit at quality 75.

DPIA4 pixelsOne A4 page under 3 MBLetter pagePages at q75
72 DPI 595 × 842 quality 95+ quality 95+ 37
100 DPI 827 × 1169 quality 95+ quality 95+ 21
150 DPI 1240 × 1754 quality 95+ quality 95+ 11
200 DPI 1654 × 2339 quality 95+ quality 95+ 7
300 DPI 2480 × 3508 quality 95+ quality 95+ 3

Readable pages and photos in 3 MB

At 3 MB, 17 typed A4 pages scanned at 150 DPI fit at quality 50 or better, and 11 at 200 DPI: enough for a short multi-page document. 6 photos of 1600 × 1200 at quality 70 also fit.

A single page at 300 DPI gets quality 95+; there is room to keep the scan near its original quality. Full-size 12 MP photos (4032 × 3024, our landscape sample, extrapolated from encodes up to 3000 px) that fit together in 3 MB: 1 at quality 60, 1 at quality 75, none at quality 90.

One image free, several merged with Pro

Free: each image becomes its own one-page PDF under 3 MB. Pro: several images merged into one PDF under 3 MB, on your device; 10 pages get 299,473 bytes of JPEG each.

How to turn a JPG into a PDF under 3 MB

  1. Open the tool above

    Preset: PDF output, at most 3 MB.

  2. Add the JPG

    Drop, paste or pick it (PNG, WebP and HEIC work too).

  3. Choose the page

    Keep the picture's own size or fit it on A4 or Letter.

  4. Download

    name-3mb.pdf arrives with its exact byte count (3,000,000 bytes or less).

Sources

  1. Measured by PixelFit with sharp 0.35.5 / libvips 8.18.7 on 31 October 2026.
  2. 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
  3. Paper sizes, Markus Kuhn, checked 31 October 2026: cl.cam.ac.uk/~mgk25/iso-paper.html
  4. 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 3 MB?

Drop the JPG into the tool on this page, preset to PDF under 3 MB: the picture is compressed to 2,999,260 bytes or less, so the PDF ends at or below 3,000,000 bytes.

Can I convert JPG to PDF for free?

Yes, one image per PDF, with no upload. Under 3 MB a full 12 MP phone photo keeps all its pixels at quality 79; merging several JPGs is Pro.

How many pages fit in a 3 MB PDF?

About 17 typed A4 pages scanned at 150 DPI at quality 50 or better, or 11 at 200 DPI; 6 photos of 1600 × 1200 at quality 70.

What DPI should a scan have for a 3 MB PDF?

One typed A4 page fits under 3 MB at 600 DPI or more (extrapolated) at quality 50, and at 600 DPI or more at quality 75; any of the usual 72 to 300 DPI settings works, up to 300 DPI.

Why is the PDF bigger than my JPG?

A PDF wraps the JPEG in page, image and cross-reference objects: 740 bytes for one page in PixelFit's writer, about 502 more per added page.

Related

Other PDF size limits

More for 3 MB

Pixel sizes that fit 3 MB

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