How to convert HEIC to PNM
To convert HEIC to PNM, upload your HEIC file, choose PNM as the output format and press Convert. The finished PNM file is ready to save to your phone or computer in seconds, free, with no watermark and no sign-up. Your file is deleted from our server about 30 minutes after the conversion.
This free online converter changes HEIC images into PNM files in seconds, with no software to install and no watermark. You can convert several files at once, resize them and choose the quality for formats that support it. Metadata such as location tags is removed from the output for privacy.
Reasons to switch from HEIC to PNM
- One extension for the whole Netpbm family
- Uncompressed and simple
- Friendly to scripting
- Works with: GIMP, ImageMagick, Netpbm and OpenCV
What to expect from this conversion
- HEIC is lossy and PNM is not, so the file will usually get larger. Converting cannot bring back detail that HEIC compression already removed.
- PNM has no transparency, so transparent areas are filled with a background colour. White by default, and you can choose another colour in the options.
- PNM cannot store animation here, so only the first frame of an animated HEIC is saved.
- Browsers do not display PNM files, so use it in editors, print workflows or development tools rather than on a web page.
HEIC vs PNM
| Property | HEIC | PNM |
|---|---|---|
| Full name | High Efficiency Image Container | Portable Anymap |
| Released | 2015, MPEG | 1988, Jef Poskanzer (Netpbm) |
| Compression | Lossy | None (uncompressed) |
| Transparency | Yes | No |
| Animation | Yes | No |
| Bit depth | 8 or 10-bit | 1, 8 or 16-bit |
| Shown in browsers | No | No |
| Best for | saving space on iPhones; Apple photo libraries | Unix-style image pipelines; teaching and research |
Steps to convert HEIC to PNM
- Drop your HEIC image file onto the converter, or click to choose it.
- Check that PNM is selected as the target and adjust the options if you want.
- Press Convert, then download your new PNM file when it finishes.
Tips for the best result
- Use quality 80 to 90 for photos: it is visually close to the original at a much smaller size.
- Set a width if the image will be shown on a small screen, which also reduces the file size.
- Choose a background colour before converting transparent images to a format without transparency.
Frequently asked questions
How do I convert HEIC to PNM?
Drop your HEIC files on the converter, confirm that PNM is the target and press Convert. Download each file or the whole batch as a ZIP.
Is the HEIC to PNM converter free?
Yes. It is free with no watermark, no sign-up and no limit on how many images you convert. The site is supported by ads.
Does converting HEIC to PNM reduce quality?
HEIC is lossy and PNM is not, so the file will usually get larger. Converting cannot bring back detail that HEIC compression already removed. The quality slider only affects formats that use lossy compression.
Will transparency be kept when I convert HEIC to PNM?
PNM does not support transparency, so transparent areas are filled with your chosen background colour (white by default).
Which programs open PNM files?
PNM files open in GIMP, ImageMagick, Netpbm and OpenCV.
How many images can I convert at once?
Up to 20 images per batch, each up to 60 MB. Files are deleted from the server about 30 minutes after conversion.