raster format

What is a .PGM file?

PGM (Portable Graymap) is the Netpbm grayscale format, storing simple uncompressed gray images often used in image-processing research.

Full name
Portable Graymap
Developed by
Jef Poskanzer
Released
1988
Extension
.pgm
MIME type
image/pgm
Transparency
Varies

How to open a PGM file

PGM opens in GIMP, IrfanView and Netpbm tools; convert to PNG/JPG to view widely.

What PGM files are used for

Photos & web images

Share, post and embed pictures across sites and apps.

Editing & design

Work with the format in editors like Photoshop and GIMP.

Storage & archiving

Keep memories and assets in a widely-readable form.

Strengths & limitations

✔ Strengths✖ Limitations
Excellent compatibilityNo transparency support
Limited support — may need converting
Large file sizes

Need more than a conversion?

Remove the background from PGM images, upscale to 4K, or generate new visuals with SharkFoto AI.

Frequently asked questions

PGM (Portable Graymap) is the Netpbm grayscale format, storing simple uncompressed gray images often used in image-processing research.

PGM opens in GIMP, IrfanView and Netpbm tools; convert to PNG/JPG to view widely.

PGM is optimised for its specific use rather than strictly lossless storage.

Use SharkFoto's free tools — upload your PGM file and convert it to a more convenient format in seconds. It's free, processed securely and never stored.

No — PGM doesn't store transparency; convert to PNG or WEBP if you need it.