Combine images into one PDF

One step, not one per image

Images to PDF takes all the images at once and writes a single document with one page per image. There is no reason to build a PDF per photo and merge them afterwards, and doing it that way loses control over the page size.

JPG and PNG are what it accepts, and it checks the actual bytes rather than the file extension, so a PNG saved with a .jpg name still works. Anything else is refused at the picker with a plain message rather than a broken page. The JPG to PDF page covers the photograph case and points at this same tool until its own preset ships.

File naming is what decides page order

This is the part that goes wrong. Sorted as text, IMG_10.jpg comes before IMG_2.jpg, because the comparison is character by character and 1 sorts before 2. A holiday folder is harmless. A 40 page contract photographed one sheet at a time is not.

Two fixes. Either set the order in the tool, dragging the thumbnails into place, or rename the files with padded numbers first: 01, 02, 03 up to 40, which sorts correctly everywhere for the rest of the file's life. For a document you will keep, the renaming is worth it.

Page size and margins

Three page size modes. Match makes each page exactly the size of its image, which is right for screenshots and for anything that will only be read on a screen. A4 and Letter put every image on a standard sheet, scaled to fit and centred, which is right for anything that will be printed or filed.

Margins are none, narrow at a quarter inch, or standard at half an inch. A landscape image on an A4 or Letter page rotates the page rather than shrinking the image into a portrait sheet.

Nothing is resampled at any setting. The pixels that go in are the pixels that come out, and the tool reopens the finished PDF and checks the embedded dimensions of every image against the originals before you download it.

When the result is too big

Photographs from a modern phone are 3 to 5 MB each, so twenty of them make a PDF around 80 MB that no mail system will take. That is a compression job, not a merging job, and it is the easy case for compression: on the public bench run, scans and photo pages met their size target on 88.9% of cases.

Do it as a second step on the finished PDF rather than shrinking each photo first, so one pass of image encoding is all the pictures ever go through.

If the file has to hit a specific number rather than merely get smaller, the compress tool takes a target size and reports what it actually reached, and the size breakdown names which pages are carrying the bytes.

The related jobs

If the images are photographs of paper rather than pictures, the multi-page scanning guide covers getting them to look like a scan instead of a snapshot, which changes both the readability and the file size.

The merge hub lists the rest of the cluster, including screenshots and loose PDF pages.

Use the converter for the image format

JPG and PNG go into Images to PDF. Standard and multi-page TIFF scans go into TIFF to PDF. WebP and BMP have their own converters. Recent iPhone photos go into HEIC to PDF.

Each focused route checks the file bytes rather than trusting the name after the dot. That catches a renamed or damaged image before the PDF is built.