HEIF to PPM Converter

HEIF vs PPM — Going From the Most Compressed to the Least

HEIF and PPM sit at opposite ends of every axis an image format has. HEIF wraps HEVC-compressed picture data in an ISO container with metadata, thumbnails, depth maps and an alpha channel. PPM is a magic number, three numbers and raw bytes.

People convert one to the other for a specific reason: a scientific tool, an image-processing pipeline, a piece of embedded software or a university assignment needs pixels it can read without a decoding library. This page covers what that costs, and the one behaviour that catches people out — transparency comes out black.

Side-by-side Comparison

The size row is the whole trade. A PPM's cost is exactly three bytes per pixel and it does not vary with content: a photograph of a blank wall and a photograph of a forest produce identical file sizes. That predictability is the point.

When to Pick HEIF

• You are storing or sharing photographs and want the smallest file for the quality.
• You need the alpha channel, Exif metadata, depth information or a burst of related images in one file.
• Your destination is Apple hardware, a modern Android phone, or software with an HEVC decoder.

When to Pick PPM

• You are feeding an image-processing pipeline, a research tool or embedded code that wants raw pixels.
• You want a format with no decoder dependency and no possibility of a decoding difference between machines.
• You are debugging and want to look at actual sample values without a library in the way.

Transparency Becomes Black

This is the behaviour to know before you convert. PPM's P6 format stores exactly three samples per pixel and has no fourth channel, so an HEIF's alpha has nowhere to go. We built a HEIF that was half solid #CC2244 and half fully transparent, ran it through, and sampled the result:

Transparent areas are composited onto black, not onto white and not onto anything you choose. If your HEIF has a cut-out subject and you convert it here, the background arrives black.

There are two ways around it: flatten the image onto the colour you want in an editor before uploading, or use a target that can hold alpha. HEIF to PNG preserves transparency, which makes it the right answer whenever alpha matters — and its Highest preset keeps true colour rather than quantising to a palette.

That measurement also shows what does survive. The opaque half came back as #CC2344 against a source authored as #CC2244 — a one-unit shift, and it happened in the HEIF encode rather than in the PPM step. HEIF's 4:2:0 chroma subsampling stores colour at half resolution in each direction, so small colour shifts are baked in before this conversion begins. The PPM itself adds nothing.

How to Convert HEIF to PPM

1. Upload Your HEIF File: Drag the .heif onto the drop zone or click "Add Files". Several files can be queued and run with the same settings.
2. Pick a Bit Depth: The choices are 8-bit (Recommended), 16-bit (High Precision) and 1-bit (Black & White). 8-bit matches what almost every HEIF actually stores.
3. Set Image Resolution If Size Matters: Keep original is the default. Because a pixmap costs exactly three bytes per pixel, the resolution controls are the only thing that changes the file size at all.
4. Convert and Download: Click Convert. Files upload over an encrypted connection, are processed on our servers, and are deleted automatically after a few hours. No sign-up, no watermark.

Frequently Asked Questions

Why is the background of my converted image black?

Because PPM cannot store transparency and the transparent pixels are composited onto black. We measured this directly: a fully transparent region came out as #000000. Flatten the HEIF onto your preferred background colour in an editor first, or convert to HEIF to PNG instead, which keeps the alpha channel intact.

Does 16-bit give me better quality from a HEIF?

Almost never. Most HEIF files store 8 bits per channel, and asking for 16-bit writes those same values into wider samples — the file doubles in size and the number of distinct colours does not change. Choose it only when a downstream program specifically requires a 16-bit pixmap.

What does the 1-bit option do to a photograph?

Not what its label implies. It keeps the three-byte-per-pixel P6 layout and simply sets the maximum sample value to 1, so each channel becomes on or off and the image collapses to eight colours — black, white and the six primaries. The file does not get smaller. It is not a greyscale or bilevel conversion.

How large will the PPM be?

Exactly three bytes per pixel plus a short header, every time. A 1920 × 1080 image is 6,220,817 bytes; a 4000 × 3000 phone photo is about 36 MB. Content makes no difference at all, because nothing is compressed. Reduce the resolution if the size is a problem — it is the only control that moves the number.

Will the Exif data from my phone survive?

No. PPM has no metadata capability whatsoever — no Exif, no colour profile, no orientation flag, no timestamp. If you need the camera information, extract it before converting or keep the original HEIF alongside the pixmap.

My HEIF is a live photo or a burst. Which image do I get?

The primary image. A HEIF can hold several pictures — burst frames, thumbnails, depth maps — and a PPM holds exactly one, so the additional images are not written. Extract them with a HEIF-aware tool first if you need more than the main picture.

Is the conversion lossless?

The PPM step is, but the source is not. HEIF is lossy HEVC at 4:2:0 chroma, so the compression artefacts and colour subsampling in your file are already there before conversion starts. The pixmap is a faithful copy of whatever the decoder produced — a perfect record of an imperfect image.

Why is there no quality setting on this page?

Because PPM is uncompressed and has no quality parameter. Bit Depth and Image resolution are the entire control surface. A quality slider would have nothing to adjust.

What is the difference between PPM, PGM and PBM?

They are the colour, greyscale and bilevel members of the same Netpbm family: PPM stores three samples per pixel, PGM one, PBM one bit. This page writes PPM, so a colour source stays colour. If you want a genuine single-channel greyscale file, PGM is the format to target rather than the 1-bit option here.