PDF is the format that survives being emailed, printed and filed. When you have photos, scans or screenshots, converting them to one PDF is usually better than sending a folder of loose images. The details that matter are page size, orientation and file size.
Fit each page to the image keeps the original pixel dimensions, so nothing is scaled or letterboxed. It is the right choice for screenshots, scanned documents and anything where detail matters — but a mixed batch of portrait and landscape shots will produce a PDF with mixed page sizes.
Force a standard page size (A4 or US Letter) gives a uniform document that prints correctly and looks professional. Images are scaled to fit inside the page with margins. This is what you want for a photo report, a portfolio or anything headed for a printer. Bear in mind that a small image stretched to fill A4 will look soft — the page is 595 × 842 points, and at 96 DPI that is roughly 795 × 1123 pixels.
Pages come out in the order you add the files, and reordering afterwards is tedious. Rename your files so they sort correctly — 01-front.jpg, 02-page.jpg — then select them in that order. Most tools have no drag-to-rearrange step, so this saves real time.
A PDF made from ten 5 MB phone photos is a 50 MB file, which most email servers will reject. Compress the images first — 1600 px on the long side at quality 82 is plenty for a document that will be read on screen, and brings each page down to a few hundred kilobytes.
Pages come out rotated. Cameras record orientation as metadata rather than rotating the pixels. Rotate the images first and save, so the fix is baked in.
White bars around every image. This happens when a portrait image is forced onto a landscape page (or vice versa). Either use "fit to image" or accept the margins as normal for a uniform document.
The PDF is blurry when printed. The source images were too small for A4. Start from higher-resolution files.
Transparent PNG areas turn black. PDFs handle transparency inconsistently; add a white background before converting if the result will be printed.
The documents people turn into PDFs — ID cards, contracts, medical scans, bank statements — are exactly the ones you should not be uploading to a random converter. Building the PDF inside the browser means the pixels never leave your device; the file is assembled in memory and downloaded straight back to you.
Try it now: Images to PDF · Compress Image