Image Converter

Convert THM to TIFF

Trying to turn a THM into TIFF? Here's the honest answer — THM isn't a readable image format — and the steps that get you a real picture.

We can't convert THM to TIFF — an THM file can't be opened by any converter. Here's why, and what actually works.

Why THM to TIFF isn't possible

1

THM can't be decoded

THM is a proprietary/undocumented format that no image library or converter can decode, so it can't be read as a source file.

2

There's no picture to convert

Because nothing can read the THM container, there's no image data a converter can extract and re-save as TIFF. Any tool that claims to do it would just fail.

3

Get the original photos instead

The real photos an THM cache was built from live in your photo library or a backup. Export those (they'll be JPG or HEIC), then convert them — that's a conversion that works.

Format details

What is a THM file?

THM is a small JPEG thumbnail saved alongside camera photos and videos — really a JPEG with a different extension.

Full name
Thumbnail Image
Developed by
Camera makers
Released
Extension
.thm
MIME type
image/jpeg
Transparency
No

How to open Rename or convert THM to .jpg to open it anywhere.

Full THM format guide

What is a TIFF file?

TIFF is a high-quality, often lossless raster format used in photography, scanning and print. Files are large but preserve maximum detail.

Full name
Tagged Image File Format
Developed by
Aldus / Adobe
Released
1986
Extension
.tiff
MIME type
image/tiff
Transparency
Yes

How to open TIFF opens in Photoshop, GIMP, Preview and professional imaging software.

Full TIFF format guide

What you can do instead

Frequently asked questions

Can any tool convert THM to TIFF?
No. THM is a proprietary thumbnail-cache blob that no image library can decode, so there's nothing to convert. Export the original photos and convert those instead.
How do I open an THM file?
THM files aren't meant to be opened directly. Recover the original images from your device's photo library or an iTunes/Finder backup, then work with those.
What can I convert to TIFF instead?
Once you have the real photos (JPG or HEIC), they convert cleanly to PNG or JPG — free, no sign-up, no watermark.