Combine Images into a Single PDF
A real PDF file assembled in your browser — one page per image, sizes of your choosing.
What this actually produces
A genuine PDF 1.4 document, assembled byte by byte in this tab: a catalog, a page tree, one page object per image, a content stream that positions the image, and an XObject holding the compressed image data. JPEG input is embedded with the /DCTDecode filter, which means the original JPEG bitstream is placed into the PDF unmodified — there is no second generation of compression, and the image is not re-encoded or degraded.
Choosing a page size
| Option | Page size | Use it when |
|---|---|---|
| A4 | 595.28 × 841.89 pt | Sending a document to a printer in most of the world |
| Letter | 612 × 792 pt | Printers and forms in North America |
| Legal | 612 × 1008 pt | Longer printed documents |
| A5 | 419.53 × 595.28 pt | Booklet pages and small handouts |
| Fit to image | One page per image pixel | Archiving scans without adding white margins |
On a fixed page size, each image is scaled down proportionally until it fits within the margin box, and centred. Nothing is cropped and nothing is distorted — a tall image and a wide image both arrive whole, just smaller.
Images must be JPEG to embed directly
PDF supports embedding a JPEG as-is. PNG, WebP and AVIF have no equivalent PDF filter, so they must be re-encoded to JPEG by a canvas before they can go in. That step is lossy even at high quality. If you have the choice, exporting to JPEG first gives you control over that trade-off; if you do not, the tool does it for you at a quality high enough that the difference is hard to see.
Resolution and file size
A PDF containing photographs is large because photographs are large. Three levers, in order of effectiveness: resize the images to the pixel count the page actually needs before combining them, reduce JPEG quality, and remove images you do not need. Placing a 4000-pixel-wide photo on an A4 page wastes pixels — 2480 pixels across is the full width at 300 dpi, and everything beyond that is stored but never displayed.
A scanned PDF is not a text PDF
Combining photographs into a PDF produces pages that are images. The text in them is not selectable, not searchable, and not readable by a screen reader. Converting such a document to real text requires OCR, which is a different operation and produces its own errors. If the source is a scanner, ask it for a searchable PDF directly.
How to use it
- Drop the images in the order you want the pages.
- Choose a page size and margin.
- Adjust the order if needed.
- Generate the PDF and open it to confirm the page count and orientation.
Worth knowing
- JPEG data is embedded with the DCTDecode filter, so it is not re-encoded.
- A4 is 595.28 × 841.89 points, where one point is 1/72 inch.
- Each image becomes one page; the page count equals the image count.
- Fixed page sizes scale to fit and never crop or distort.
Limitations
- PNG, WebP and AVIF must be converted to JPEG first, which is a lossy step.
- There is no text layer — the output is not searchable or selectable.
- No editing afterwards: pages cannot be reordered or annotated in the produced file.
- All images share one page size; mixed sizes need separate documents.
- Large batches are bounded by available tab memory.