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Convert PNG to PDF on Mac: 3 Methods

Make a PDF from PNG images on Mac with Preview, then compress if email rejects the file. Resize sources first for screen-only sharing.

By Petr Samokhin

Design file folders arrive as twelve PNG screens. The portal accepts one PDF, not a zip. One merged PDF locks page order and prints cleanly. Merging does not shrink Retina mockups. Cap width before merge when the destination is screen-only, or compress the PDF after export.

When one PDF beats many PNG files

ScenarioWhy merge into PDF
Client portalSingle upload field
Print shopFixed page sequence
Legal packetSignatures on correct pages
EmailOne attachment vs many

Reverse workflows: PDF to images on Mac , PDF to PNG on Mac . For JPEG scans: JPG to PDF on Mac .

PNG transparency may flatten to white in some PDF viewers. Flatten in your design tool when the background must be a brand color.

Method 1: Combine PNG files in Preview

Best for: Building the PDF on Mac without extra installs.

  1. Open the first PNG in Preview.
  2. View → Thumbnails.
  3. Drag other PNG files into the sidebar (or open a multi-select from Finder).
  4. Reorder thumbnails, rotate phone scans if needed.
  5. File → Export as PDF… and save.

Use zero-padded names (page-01.png) so order matches screen flow when you open many files at once.

Limitation: A folder of 3000 px mockups can produce a 30 MB PDF that Gmail rejects.

Method 2: Resize sources before merge

Best for: Screen review packets that must stay under email or portal caps.

In Preview, use Tools → Adjust Size… on each oversized PNG, or batch with Terminal:

mkdir resized
for f in *.png; do
 sips -Z 1920 "$f" --out "resized/$f"
done

Then merge the resized/ folder in Preview (Method 1). For PNG to JPEG before merge when transparency is gone, see PNG to JPG on Mac .

After merge, Preview File → Export… → Quartz Filter → Reduce File Size can help, but check small text at 100% zoom. Soft type usually means you crushed the PDF instead of resizing sources.

Limitation: Manual size checks. Quartz filters can soften UI text.

Method 3: Compress the PDF in GetCompress

Best for: Recurring client packets when the merged PDF still exceeds the portal limit.

GetCompress does not merge PNG into PDF. Build the file in Preview first, then:

GetCompress PDF settings for compressing a merged document on Mac
  1. Drop the merged PDF into GetCompress .
  2. Pick a PDF compression preset and preview a page with small type.
  3. Export a delivery copy. Keep the full-resolution merge if you still have it.
  4. Save a preset per portal when the same limit comes back every week.

PDF compression uses optimization presets, not an exact target file size.

Which method should you use

SituationStart here
Build the documentPreview
Sources are huge Retina PNGResize first, then merge
Merged file still too largeGetCompress

More detail: how to compress PDF on Mac . Cap PNG width before merge: how to compress images on Mac .

Check before you upload

Confirm page order, orientation, and one UI screen with small type. Keep full-resolution PNG sources on project storage. Write compressed deliverables to a separate folder.

When Preview alone is enough

Preview merge plus a sensible source width is enough for many one-off packets.

GetCompress fits when you rebuild the same kind of PDF every week and portals keep rejecting size. It does not replace a PDF editor for forms, signatures, or redaction.

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