How to combine scans into one PDF on a Mac
By Himanshu Ranjan · Updated 8 November 2026
To combine scans into one PDF on a Mac, select the files in Finder and run Combine › Combine into one PDF in FileDial, which puts photos and PDF pages in selection order into one new PDF. For JPGs only, Combine › Images to PDF works; for PDFs, Combine › Merge PDFs.
Which tool for which scans
Scans arrive in different forms: separate JPG or PNG photos from a phone, single-page PDFs from a scanner app, or a mix. FileDial has three combining routes. Combine › Combine into one PDF takes photos and PDF pages in selection order and writes one new PDF. Combine › Images to PDF makes one page per image, sized to the image, with A4 and Letter variants. Combine › Merge PDFs joins PDFs in selection order.
If everything is a PDF you can use Merge PDFs; if everything is a photo, Images to PDF; if it is mixed, Combine into one PDF. Pick by input and you will rarely need to redo it.
- Photos only: Images to PDF, or the A4 or Letter variants.
- PDFs only: Merge PDFs, by date or by name if you prefer.
- A mix: Combine into one PDF.
Combine them with FileDial
Order matters, so arrange the selection before you run the tool.
- Select the scans in Finder in the order you want the pages.
- Hold the right Option key to open the dial and choose the Combine category.
- Release on Combine › Combine into one PDF.
- Open the new PDF and flick through the pages in the sidebar to confirm the order.
- If a page is sideways, fix it with the Organize rotate tools, then make the file searchable.
Getting the order right
The tools follow selection order, so name your files so they sort correctly before you start. A scan app that numbers pages 1, 2, 10 sorts 10 before 2 as plain text; Combine › Merge PDFs by name uses file-name order with 2 before 10, which fixes that case, and Combine › Merge PDFs by date goes oldest file first by created date.
If the order is wrong after the fact, do not start again: use Organize › Reorder pages… on the result, typing the page order you want.
Page size and orientation
Mixed scans produce pages of different sizes: a phone photo next to an A4 scanner page. Images to PDF sizes each page to its image, which is faithful but can look uneven. If you want uniform pages, use the A4 or Letter variants, or after combining run Pages › Resize to A4 or Pages › Resize to Letter. Remember that resizing tools flatten links and form fields.
For photos taken at an angle, straighten first with Adjust › Scan to PDF…, which straightens document photos into a searchable PDF. If the pages are scanner output that is only slightly tilted, OCR › Straighten scanned pages… applies to PDFs.
Make the result searchable and small
After combining, two finishing steps are worth it. OCR › Make searchable adds a text layer so you can search the whole bundle. Then check size: a bundle of phone photos can run to tens of megabytes. Compress › Compress keeps text selectable with images at 144 dpi, which is fine for screens; use Compress › Compress PDF (light) for 200 dpi if the pages will be printed.
If the bundle is for a portal with a limit, use one of the target-size tools in the Compress category.
A worked example: a mortgage document pack
You have eleven items: six phone photos of pay stubs, three single-page PDFs from a scanner app and two statements as multi-page PDFs. Rename the files with leading numbers in the order the lender listed them, select all eleven, and run Combine › Combine into one PDF. The result is one PDF in that order, with photos as pages and the PDFs expanded into their pages.
Then run OCR › Make searchable, flick through the thumbnails once, and check the size. If the lender has a limit, run Compress › Compress under 10 MB or Compress › Email-safe (under 20 MB). Keep the numbered originals in a folder in case the lender asks for a revised order.
Common mistakes
Selecting in the wrong order is the main one: Finder's selection follows its sort order, so sort by name first. The second is mixing portrait and landscape without checking; rotate sideways pages before combining. The third is merging a locked PDF: remove the password first with Sign & Lock › Remove password… The fourth is combining before cleaning up: delete blank scanner pages with Organize › Remove blank pages while the file is still separate. The fifth is forgetting to compress, then discovering the email will not go.
Preview can combine PDFs: Apple's guide describes dragging pages into the sidebar thumbnails of another PDF. It works well for a few files and when you want to fine-tune order by dragging. For many files, or for a mix of photos and PDFs, selecting them in Finder and running one tool is quicker.
Bundles of scans are often IDs, bills and contracts. Online mergers receive every page. FileDial works locally and writes the new PDF beside the originals, which stay as they were.
Questions
How do I put JPG scans into one PDF on a Mac?
Select the JPGs in Finder in page order and run Combine › Images to PDF, or Combine › Combine into one PDF for a mix with PDFs. Each image becomes one page. Check the order in the result and fix it with Organize › Reorder pages… if needed.
Why are my scanned pages in the wrong order?
Tools follow selection or file-name order, and plain sorting puts 10 before 2. Use Combine › Merge PDFs by name, which sorts 2 before 10, or rename files with leading zeros. You can also repair the result afterwards with Organize › Reorder pages…
Can I combine scans of different sizes?
Yes, but pages will keep their own sizes unless you choose a variant. Use Combine › Images to PDF (A4) or (Letter) for photos, or run Pages › Resize to A4 or Resize to Letter on the result. Note that resizing flattens links and form fields.