TIFF vs PNG on Mac — which to keep, which to convert

You inherited a folder of scans and they’re all .tif files. You upload one to a CMS and it gets rejected. You email another to a client and it bounces because it’s 80 MB. Meanwhile your screenshots are PNGs and they just work everywhere. Both formats are lossless — so what’s actually different?

What TIFF is

TIFF (Tagged Image File Format) is the print and scanning industry’s lossless workhorse. It supports 16-bit and 32-bit colour, multiple pages, layers, colour profiles, CMYK, and a range of compression schemes (LZW, ZIP, JPEG-inside-TIFF). Files are big because they’re meant to be: TIFF is for archival quality, not the web.

What PNG is

PNG (Portable Network Graphics) is the web’s lossless format. It supports 8-bit and 16-bit colour, transparency, and uses zlib compression that’s smaller than TIFF for typical web content. Every browser, every CMS, every image tool handles it.

When to keep TIFF

• Print work, especially CMYK pre-press.
• Scans you want to archive at maximum quality.
• Multi-page documents (TIFF supports pages; PNG doesn’t).
• Anything that needs 16-bit colour for editing latitude.

When to convert to PNG

• Uploading anywhere on the web.
• Sharing with anyone who isn’t doing print or scientific work.
• Reducing file size — a typical photo TIFF is 3–5× the size of the equivalent PNG.
• Working with tools that don’t support TIFF (most CMS upload forms, many web design apps).

The native way

Preview. Open the TIFF, File → Export, choose PNG, save.

sips in Terminal:

sips -s format png scan.tiff --out scan.png

Folder version:

for f in *.tif *.tiff *.TIF *.TIFF; do
  sips -s format png "$f" --out "${f%.*}.png"
done

The faster way

Drag the folder into Melt, pick PNG as the output, click Compress. Useful when you’ve got dozens of scans and want them all converted at once. Download Melt.

Batch convert in Melt

1. Open Melt.
2. Drag your TIFF files in.
3. Set output to PNG.
4. Click Compress.

What you lose, what you keep

TIFF → PNG drops you from up to 32-bit colour down to 16-bit max. If your TIFF is 8-bit (most scans), you lose nothing visually. CMYK TIFFs get converted to RGB, which matters if you’re prepping for print. Multi-page TIFFs become a single PNG of the first page only — for multi-page work, convert to PDF instead. Keep TIFF masters for anything destined for print, and PNG copies for everything else.