🖼️ JPG to PDF Converter
Turn JPG, PNG and WebP images into a single PDF. Page size matched to each image or set to A4 or Letter, auto orientation, margins. Nothing is uploaded.
Choose images, or drop them here
JPG, PNG, WebP, GIF, BMP. The PDF is built in this tab and nothing is uploaded.
JPG and PNG files are embedded exactly as they are, so this setting does not touch them. It applies only to formats a PDF cannot hold natively — WebP, GIF, BMP and AVIF — which are converted to JPG on the way in.
What JPG to PDF Converter Does
Putting images into a PDF is embedding, not conversion. A JPEG placed in a PDF is stored as the same JPEG bytes it always was, wrapped in an object that says where on the page to draw it. Nothing is re-compressed and no quality is lost — which also means the PDF is roughly as large as the images that went into it. Ten 4 MB photos make a 40 MB PDF, and no page setting changes that.
The decision that actually shapes the result is the page size. Forcing every image onto A4 is what produces the wide white bands people complain about: a phone photo is 4:3 or 3:4, A4 is neither, and the difference has to be padded. Matching the page to each image removes the padding entirely, and is the right default unless a printer or a portal insists on a paper size.
When a paper size is required, the image is contained inside it — scaled by whichever axis is tighter so the whole picture fits — and centred. It is never cropped and never stretched. Automatic orientation turns the page to match each image, so a landscape photo gets a landscape page instead of shrinking to fit a portrait one.
PDF measures everything in points, 72 to the inch, which is why an A4 page is 595.28 by 841.89 units rather than 210 by 297. The margin you set in millimetres is converted for you.
How to Use JPG to PDF Converter
- Add your images, or drop them onto the box
- Put them in page order with the arrows, or sort by file name
- Choose the page size — match each image for no white bands, or A4 or Letter for printing
- Set a margin, then create the PDF
Formula Used by JPG to PDF Converter
Fitting an image inside a page without distorting it
scale = min( (W − 2m) ÷ w , (H − 2m) ÷ h )
- W, H
- page width and height in points
- w, h
- image width and height in points
- m
- margin in points — millimetres ÷ 25.4 × 72
Worked example
A 4032 × 3024 photo on A4 landscape (841.89 × 595.28 pt) with a 10 mm margin.
- Margin: 10 ÷ 25.4 × 72 = 28.35 pt
- Available: 841.89 − 56.69 = 785.20 wide, 595.28 − 56.69 = 538.59 high
- Scale by width: 785.20 ÷ 4032 = 0.1947
- Scale by height: 538.59 ÷ 3024 = 0.1781
- Take the smaller, 0.1781, so the image fits on both axes
Result: 718.1 × 538.6 pt, centred — the full picture on the page, proportions intact.
Page sizes in PDF points
PDF’s default user space unit is 1/72 inch, so every paper size has a point equivalent.
| Page | Physical | Points |
|---|---|---|
| US Letter | 8.5 × 11 in | 612 × 792 |
| US Legal | 8.5 × 14 in | 612 × 1008 |
| A4 | 210 × 297 mm | 595.28 × 841.89 |
| A5 | 148 × 210 mm | 419.53 × 595.28 |
| A3 | 297 × 420 mm | 841.89 × 1190.55 |
Which page mode to choose
| Goal | Page size | Why |
|---|---|---|
| Send scans to someone to read on screen | Match each image | No wasted space, smallest sensible file |
| Print the document | A4 or Letter | A printer needs a real paper size to lay out |
| Upload to a portal that checks page size | Whatever it specifies | Contain, do not crop — nothing is lost |
| A mix of portrait and landscape scans | A4 or Letter with auto orientation | Each page turns to suit its image |
How to Read Your Result
Compress first, then build the PDF
If the output has to be under a size limit, shrink the images before assembling them. Embedding is not compression, so there is nothing the PDF step can do about it — and doing it in that order leaves the quality trade-off visible and under your control instead of hidden inside a black box.
JPG and PNG are embedded untouched
The quality slider governs only formats a PDF cannot hold natively — WebP, GIF, BMP, AVIF — which are converted to JPG on the way in. Your JPGs and PNGs go in byte for byte, with no second round of loss.
Sort by name handles numbered scans correctly
Natural sorting puts scan-2 before scan-10. Plain alphabetical sorting, which most file pickers use, puts scan-10 first — the classic cause of a PDF assembled in the wrong order.
Limitations & Accuracy Notes
- Transparency is flattened onto white. A PDF page has no alpha channel to fall back on.
- There is no OCR: the result is pictures of your documents, so the text in them is not selectable or searchable.
- No automatic deskewing, cropping, edge detection or contrast correction — this assembles the images you give it.
- Colour profiles are not embedded; images are treated as sRGB.
- Everything is held in memory while the PDF is built, so a hundred full-resolution photos may exhaust an older phone.
Frequently Asked Questions
How do I stop the white bands around my photos?
When should I choose A4 or Letter instead?
Does this re-compress my photos?
Why is my PDF so large?
Can I control the page order?
Are my photos uploaded?
References & Further Reading
- ISO 32000-1 / PDF 32000 specification (Adobe copy) — Default user space unit of 1/72 inch, and how images are embedded as XObjects
- pdf-lib — The library building the document in your browser