Manatee

How to convert TIFF to PNG on a Mac

· 6 min read

Open the TIFF in Preview, choose File > Export, set Format to PNG, and click Save; that is the whole job for a single file. For a batch, select the TIFFs in Finder, right-click, and use Quick Actions > Convert Image with PNG as the format. Both keep the original TIFF untouched, and because PNG is lossless, nothing about the image quality changes.

Why convert TIFF to PNG at all

TIFF is the format of scanners, print shops, and archival workflows. It stores images without loss, can hold multiple pages in one file, and supports CMYK color, layers, and 16 bits per channel. That flexibility is also why so many things choke on it: web forms reject it, messaging apps refuse to preview it, some email clients show it as an attachment icon instead of a picture, and the files are large because they are often uncompressed.

PNG is also lossless, but it is the lossless format the web understands. Every browser, chat app, CMS, and upload form accepts it. Converting a TIFF to PNG loses nothing about the pixels (with a few exceptions covered below), usually makes the file smaller, and makes it open everywhere.

If your goal is a much smaller file for email and the image is a photograph, JPEG is a better target than PNG; the same steps apply, you just pick JPEG in the format menu.

Convert one file with Preview

  1. Double-click the .tif or .tiff file. It opens in Preview by default on every version of macOS.
  2. Choose File > Export (not Export As PDF).
  3. In the Format pop-up, choose PNG. If PNG is not listed, hold Option while clicking the menu to see the full list.
  4. Optionally tick Alpha to keep a transparent background, if the TIFF has one.
  5. Choose a location and click Save.

Preview writes a new .png file and leaves the TIFF alone. For a multi-page TIFF, Preview shows the pages in the sidebar (View > Thumbnails); Export saves the page currently selected. To get every page, select each one in turn and export again, or use the batch method below, which treats each page the same way, one PNG per file, first page only. A multi-page TIFF that needs to stay multi-page is better exported as a PDF (File > Export As PDF), since PNG has no concept of pages.

Convert a folder of TIFFs at once

Finder’s Convert Image Quick Action has been available since macOS Monterey and handles any number of files.

  1. Select the TIFF files in Finder.
  2. Right-click and choose Quick Actions > Convert Image.
  3. Set Format to PNG.
  4. Set Image Size to Actual Size unless you deliberately want a downscaled copy.
  5. Decide on Preserve Metadata. Leaving it on keeps scanner and camera information; turning it off gives you a cleaner file for public posting.
  6. Click Convert to PNG.

The PNGs appear next to the originals. If the Quick Action is missing from the menu, enable it in System Settings > General > Login Items & Extensions > Finder.

From Terminal with sips

Apple ships a command-line image tool called sips that can do the same conversion and is easy to script.

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

Every TIFF in the current folder:

for f in *.tif *.tiff; do [ -e "$f" ] && sips -s format png "$f" --out "${f%.*}.png"; done

sips converts the first page of a multi-page TIFF and ignores the rest, so use it for single-image files.

When the TIFF will not open: Manatee

Occasionally a TIFF refuses to open in Preview. It shows a blank white canvas, an error that the file “may be damaged,” or a thumbnail with nothing behind it. The usual causes are an unusual compression scheme (some fax and scanner software uses old or proprietary ones), a CMYK file with an embedded profile that macOS does not like, or a file that was truncated during a download or copy.

Manatee accepts .tif and .tiff as input and converts them to PNG, JPEG, HEIC, and other targets using its own bundled image engine rather than the macOS one, so it can often read a TIFF that Preview rejects.

  1. Open Manatee and choose Convert.
  2. Drop the TIFF (or a whole folder of them) into the window.
  3. Choose PNG as the target and click Convert.
  4. Find the new PNG next to the original. The TIFF is never modified.

Manatee converts what it can read; it does not rebuild image data that is physically missing. A TIFF cut off halfway through a download will give you a PNG with the top half of the picture and a gray or black bottom half, which is honest but not magic. If a file is truncated, getting a complete copy from the source is the real fix; why files get corrupted and what can actually be recovered explains where the line is. Manatee also does not resize, crop, or color-correct; for those, finish in Preview.

What to know about the result

Bit depth. PNG supports 16 bits per channel, so a 16-bit TIFF from a scanner or camera can be preserved without loss. Preview’s PNG export typically writes 8-bit, which is fine for viewing and the web but drops the extra precision. If you need to keep 16-bit data, check the result’s bit depth with Preview’s Tools > Show Inspector and, if it reads 8, keep the TIFF as your master.

CMYK. PNG is an RGB format. A CMYK TIFF from a print workflow gets converted to RGB along the way, and colors can shift slightly, especially saturated cyans and oranges. For print, keep sending the TIFF; use the PNG for screen.

Layers. A layered TIFF saved from an image editor is flattened on export. Preview and Manatee both read the composite image, not the individual layers. Keep the layered original if you will edit it again.

Transparency. TIFF alpha channels carry into PNG cleanly, provided you leave Alpha enabled in Preview’s export dialog.

File size. A PNG will usually be smaller than an uncompressed TIFF, sometimes dramatically so for flat-color images like diagrams and scanned text. For photographs the saving is modest; PNG compression does not do much with noisy detail. If size is the problem, see how to convert BMP to PNG on a Mac for the same discussion applied to another bulky format, or export to JPEG instead.

Metadata. Scanner and camera EXIF is carried over by default. Use Manatee’s Clean mode or the Finder Quick Action’s metadata checkbox if the image is going public.

Questions

Does TIFF to PNG lose quality?

Not in the pixel data; both formats are lossless. The exceptions are 16-bit depth being reduced to 8-bit in some tools, and CMYK being converted to RGB, both explained above.

Can I convert a multi-page TIFF to a single PNG?

No. PNG holds exactly one image. Export each page separately, or export the whole thing as a PDF if you need the pages together.

The PNG came out with a black background instead of transparent.

The TIFF probably had no alpha channel in the first place, or Alpha was unchecked in Preview’s export dialog. Re-open the TIFF in Preview and look for the Alpha checkbox when you export again.

My PNG is “invalid or unsupported” after conversion.

That usually means the conversion was interrupted or the destination filled up. Convert again, and if it keeps happening with the same TIFF, see PNG file is invalid or unsupported on Mac.