How to Combine JPG and PNG Images Into One Ordered PDF File

Most of the time you do not need a fancy document. You need twenty photos to become one file that other people can open, scroll, and print in the right order. A reimbursement portal wants a single attachment. A counterparty wants the signed pages bound together. Your kid's school wants the homework as one upload, not a folder of IMG_4471.jpg through IMG_4493.jpg.

The mechanics are simple once you see them clearly: each image becomes exactly one page, the pages follow the order you set, and the conversion can run entirely on your own machine so private scans never touch a stranger's server. This guide walks through how that works, with a worked example of stitching contract photos together, and explains the small decisions (page size, fit, margin) that separate a tidy PDF from a sloppy one.

You can follow along in the Image to PDF tool while you read.

One image, one page — and why that rule matters

The core behavior is worth stating plainly because it removes a whole class of surprises: every image you add becomes one page in the PDF, scaled to fit the page while keeping its aspect ratio. No image gets squished, no two photos get crammed onto one sheet, and the count is predictable — thirty images in, a thirty-page PDF out.

"Scaled to fit while keeping aspect ratio" is the part people get wrong with screenshot-and-paste workarounds. A 4032×3024 phone photo and a tall 1080×1920 receipt are very different shapes. Forcing both onto an A4 page without respecting their proportions stretches faces and warps text. The right approach scales each image down until it fits inside the page's printable area, leaving thin white bands on whichever axis is shorter. The picture stays honest; the page stays standard.

There is also a mode for people who do not want any white bands at all: fit-to-image, where the page itself becomes the photo's own size. Nothing is rescaled and nothing is letterboxed, which is what you want for product shots or scans that must keep their native dimensions.

Setting the page order before you build

Order is not an afterthought — it is the whole point of combining images. Photos rarely arrive in the sequence you want. Phone galleries sort by capture time, email attachments sort by whatever the sender clicked first, and a stack of scans comes in whatever order the pages landed on the glass.

Each image shows up as a card with a thumbnail, its filename, and a number badge that reflects its current position. You drag a card up or down to move it, and the top-to-bottom order in the list is exactly the page order in the finished PDF. On a phone, the up and down arrow buttons next to each card do the same job without a fiddly drag.

Two habits make this painless. First, rename source files with a leading number if you already know the sequence — 1-cover.png, 2-detail.png — so they land close to right and you only nudge a few. Second, watch the number badge, not the thumbnail, when you reorder; the badge is the source of truth for what page each image will become.

A worked example: photos of a signed contract into one PDF

Here is the case that pushed me to take this seriously. A counterparty signed a four-page agreement, photographed each page with their phone, and emailed the shots back as four loose JPGs named after timestamps. I needed one clean PDF, in page order, to file with our records — and I did not want signature pages with names and account references sitting in some free online converter's upload queue.

The flow took under a minute:

Add the four JPGs. They came in as cards, but in timestamp order, which happened to be pages 2, 1, 4, 3.
Reorder by dragging. I pulled page 1 to the top and dropped page 3 before page 4, watching the number badges flip to 1-2-3-4.
Choose fit-to-image. Each scan kept its own dimensions with no rescaling. That matters if anyone later compares the PDF against the paper — no surprise resizing to explain.
Set the margin to zero. Contract scans already have their own paper border; I did not want a second one stacked on top.
Build. One click produced images.pdf, four pages, correct order, downloaded straight to my machine.

The whole job ran in the browser tab. The Network panel in DevTools sat at zero requests the entire time — the signed pages never left the laptop.

Page size, fit, and margin: the three knobs that matter

Once the order is right, three settings decide how each image lands on its page.

Page size. A4 and US Letter put every image on a standard printable sheet, which is what you want for anything destined for a printer or a portal that expects normal paper. Fit-to-image makes each page the image's own size — best for native-resolution product shots, mixed-orientation scans, or anything that should not be rescaled at all.
Fit vs. fill. Fit (contain) scales the image to sit fully inside the margins with nothing cropped; you may see white bands on one axis. Fill (cover) scales the image to cover the whole sheet and crops the overflow at the page edge. Use fit when every pixel must stay visible — receipts, contracts, anything legal. Use fill for portfolios and spreads where edge-to-edge looks better and a little cropping is fine.
Margin. A blank border around the image, from 0 to 144 points (72 points is one inch). Zero is right for scans that already have their own border; a small margin gives receipts and worksheets a clean frame.

One honest trap: choosing fill and then being surprised when a photo's edges get cropped at the page border. Fill always trades white margins for edge-to-edge coverage, so it crops the overflow on the long axis. If you need the entire image visible, use fit.

If your images are larger than you'd like the final PDF to be, the converter does not re-compress them — the PDF is roughly the sum of your source files. Shrink the photos with the image compressor before building, and the PDF comes out proportionally smaller.

Why local conversion protects private documents

The reason to care where the conversion runs is the kind of thing people put in these PDFs: receipts with card numbers, ID scans, signed pages with real names, medical paperwork. A typical online converter uploads every image to a server, processes it there, and hands back a download link. Your private documents now live, however briefly, on someone else's infrastructure, governed by a privacy policy you did not read.

Local conversion removes that step entirely. Each file is read into memory inside your browser tab and assembled into a PDF by JavaScript running next to the page — no upload, no server round trip. You can verify it yourself: open the DevTools Network panel while you build, and the request count stays at zero. The only thing written to disk is your page-layout preference (size, orientation, margin, fit), saved on your own device.

One caveat worth knowing: when JPEG and PNG images are embedded byte-for-byte, any metadata baked into the source photos — camera model, capture date, sometimes GPS coordinates on phone shots — carries through into the PDF. If you are sending the result to a stranger, strip EXIF from the photos first, or clear it through Document Properties in your PDF viewer.

Where this fits in a larger workflow

Combining images is usually one step in a bigger task. Once you have a PDF, you might need to split it, merge it with another, or fix the source images before they ever become pages. A few tools pair naturally:

Built a PDF in two batches because a giant job got slow? Stitch them with the PDF merger.
iPhone HEIC photos get skipped because browsers can't decode them — convert them to JPG first with the image format converter, then drop the JPGs in.
Pages coming out larger than the printer or portal allows? Shrink them with the image resizer before building.

The pattern is the same throughout: predictable pages, an order you control, and files that stay on your machine. That is most of what a good image-to-PDF step needs to be.

Made by Toolora · Updated 2026-06-13