JPG to PDF — Combine Images into One PDF

One image per page, in the order you set

This tool does one job cleanly: it takes the images you give it and stacks them into a single PDF, one image per page, in the order they appear in the list. That is genuinely useful — five phone photos of a signed contract, a folder of receipts, a set of scanned certificates — because a single PDF is far easier to email and file than a pile of loose JPGs, and it opens the same way on every device.

The order is yours to control. After you upload, each image gets up and down arrows; the top of the list is page one. That is worth doing deliberately, because file managers sort by name or date in ways that rarely match the order you actually want — IMG_4021 is not necessarily page one. Set the order before you convert and the PDF comes out right the first time.

Fit to page versus original size — and why the default matters

The single most useful setting here is page size, and it exists because the two things people make with this tool want opposite behaviour. If you are making a document — receipts, scans, forms — you want every page the same size so it prints and reads like a normal PDF. That is Fit to page: each image is scaled down to sit inside an A4 or Letter sheet, centered, with a small margin. Orientation can follow each image automatically, so a wide photo lands on a landscape page and a tall one on portrait.

If instead you want the PDF to preserve each image’s exact proportions — a photo set, artwork, anything where a forced margin would be wrong — Original image size makes each page exactly as large as its image. The conversion uses the standard 96 pixels-per-inch reference, so a 1200×800 pixel image becomes a 12.5×8.33 inch page. The trade-off is that pages will differ in size whenever your images do, which looks deliberate for a photo book and messy for a document. That is why Fit to page is the default.

Why a phone photo used to come out sideways — and why it no longer does

Here is a subtlety that trips up almost every image-to-PDF converter, this one included until recently. When you photograph a document with a phone, the sensor often records the pixels in one fixed orientation and then writes a small EXIF Orientation tag that says “display this rotated 90°.” Your photo gallery reads that tag and shows the picture upright, so you never notice the pixels themselves are stored on their side.

The problem is that the PDF library doing the embedding reads only the image’s stored width and height — it does not look at the orientation tag at all. So the raw sideways pixels get placed on the page as-is, and a portrait photo of a contract lands in the PDF in landscape, rotated a quarter turn. It looked upright in your camera roll, which is exactly why the sideways PDF is such a surprise.

This tool now reads that tag before embedding. If a JPEG declares any of the eight orientation values that mean “rotated” or “flipped,” the image is first drawn onto a canvas with the matching transform applied, so the corrected, upright pixels are what get written into the PDF. Photos that are already upright — orientation value 1, or no tag at all — are passed straight through untouched, so nothing is recompressed needlessly. PNGs skip the check entirely because the PNG format has no orientation tag to begin with.

By the numbers

A PDF measures everything in points, where one point is 1/72 of an inch. Image pixels, by the web convention, are read at 96 pixels per inch. So the conversion this tool applies is points = pixels × 72 ÷ 96 — a 0.75 factor. That is why a 1200-pixel-wide image becomes a 900-point (12.5-inch) page in Original size mode rather than a 1200-point one; skipping that conversion is the classic bug that produces absurd 16-inch pages.

The fixed page sizes work out to 595 × 842 points for A4 (210 × 297 mm) and 612 × 792 points for US Letter (8.5 × 11 in). In Fit to page mode the tool subtracts a 24-point margin on every side — about a third of an inch — then scales the image down by whichever factor (width or height) is the tighter fit, so the whole image always lands inside the printable area with a clean border and its aspect ratio intact. It never scales an imageup, so a small image stays its own size rather than turning blurry.

What “no quality loss” does and does not mean

This step does not re-encode your images. A JPG is embedded with its original bytes intact, and a PNG the same way, so the tool itself adds no compression artefacts. It is honest to say there is no additionalloss — but not that the result is lossless in absolute terms, because a JPG is already a lossy format. If your source photo was saved at low quality, that is baked in and this tool faithfully carries it through; it cannot add back detail that was never stored.

The practical consequence is file size. Embedding the original bytes means a stack of high-resolution phone photos produces a large PDF — several megabytes per page is normal. If a portal caps the upload size, convert first and then shrink the result with the PDF compressor or, for image-heavy files specifically, the PDF photo compressor. Shrinking the images before converting, with the image compressor, works too and gives you a quality slider with a live size readout.

The transparency footgun with PNGs

JPGs are always opaque, so they just work. PNGs can carry transparency, and the tool keeps it — which is usually what you want, but occasionally surprises people. Where a PNG is transparent, the PDF page has no pixels there at all; the page background shows through. On a normal white viewer that reads as white, so you may never notice. It becomes visible the moment the page is printed on coloured stock, or placed over other content, where the “white” turns out to be a hole.

If you need a solid white background under a transparent PNG, flatten it onto white before converting. If you do not care — most document scans are fully opaque anyway — there is nothing to do.

There is also a file-size angle to the JPG-versus-PNG choice. A photograph saved as PNG is typically several times larger than the same photograph as JPEG, because PNG is lossless and does not discard the fine tonal detail that JPEG throws away. When your source is a photo, keeping it as JPEG produces a much smaller PDF for no visible difference; PNG earns its size only for screenshots, line art, and anything with hard edges or genuine transparency. If you have a mix, it is fine to feed both into the same conversion — each page simply carries whichever format you gave it.

Related tools

Going the other direction — pulling the images back out of a PDF — is the PDF to JPG tool. If you already have several PDFs and want them in one file, use merge PDF rather than converting to images first. And when the finished PDF is heavier than a portal allows, the PDF compressor brings the size down.