PPM to AVIF Converter

PPM to AVIF Converter

PPM is the Netpbm Portable Pixmap: a three-line ASCII header followed by raw RGB samples, with no compression, no alpha channel and no embedded colour profile. It is the format OpenCV, ImageMagick, FFmpeg, Pillow and the Netpbm command-line tools reach for when they need a working intermediate that any program can parse in a dozen lines of code. AVIF is the opposite end of the same pipeline — the AV1 Image File Format, published by the Alliance for Open Media, which takes those raw samples and compresses them harder than JPEG or WebP can. This page documents exactly what goes in, exactly what comes out, and where the output stops short of what the AVIF specification allows.

PPM Format at a Glance

AVIF As This Page Writes It

The AVIF specification is broad — 8, 10 and 12-bit depths, alpha, image sequences, lossless mode. What this converter emits is a narrower, well-defined subset, verified by inspecting the actual output files.

How to Convert PPM to AVIF

1. Upload Your PPM File: Drag and drop the pixmap or click "+ Add Files". Both P3 and P6 pixmaps are accepted, and several can be queued and converted in one batch.
2. Choose a Quality Preset: The Quality Preset dropdown opens on "Very High (Recommended)" and runs Highest, Very High, High, Medium, Low, Very Low, Lowest. Those seven rungs map to encoder quality values of 100, 95, 90, 80, 70, 60 and 50 respectively.
3. Or Set a Specific File Size (Optional): Switch to Specific file size to name a byte budget instead — the field is pre-filled at 8 MB and takes bytes, kilobytes or megabytes, with an Auto Scale toggle that lets the encoder shrink dimensions to hit the number. Independently, Image resolution stays on "Keep original" until you set a percentage, a preset height or explicit dimensions.
4. Convert and Download: Click Convert and save the .avif. Files upload over an encrypted connection, are processed on our servers, and are deleted automatically after a few hours. No sign-up, no watermark.

What Each Preset Actually Emits

Measured on one 1600 x 1200 test image saved as a P6 pixmap of 5,760,017 bytes, encoded through the same saver and the same quality values this page uses. Content drives these numbers heavily — grain and fine texture cost far more than smooth shading — so read the shape of the curve rather than the absolute bytes.

Two things are worth pulling out. First, the default preset landed at roughly a third of the JPEG at the same rung, which is the usual reason to pick AVIF at all. Second, the chroma column changes between High and Medium: the top three presets keep full-resolution colour, and Medium downward halves it in each direction. If your image has saturated red or magenta edges — UI screenshots, charts, logos on colour — staying at High or above is worth more than the byte saving.

Frequently Asked Questions

Is the AVIF a clean first-generation encode, or am I stacking compression?

Clean. A PPM has no compression of its own — it is a header plus a flat array of samples — so this is a single, first-generation lossy step with no inherited artifacts for the encoder to spend bits preserving. That is the ideal input. Encoding a PPM straight to AVIF is meaningfully better than exporting your pipeline to JPEG first and converting that, because a JPEG has already discarded detail that no later encoder can recover.

Does this page produce 10-bit or HDR AVIF?

No. The AVIF specification permits 8, 10 and 12-bit depths, but the encoder here is driven with a quality value only, and every output we inspected reported 8 bits per channel. There is also nothing wider to preserve on the way in: a PPM stores plain integer RGB samples with no HDR metadata and no colour profile, so there is no high dynamic range in the source to carry through.

Can I get a lossless AVIF from my pixmap?

Not from this page — the lossless toggle does not render here, so the output is always lossy AV1. If you need the exact samples back for pixel-diff testing, reproducible research or further numeric processing, keep the PPM itself or use PPM to PNG, which compresses without discarding anything.

How much smaller will the AVIF be than the PPM?

By a very large factor, because the starting point is uncompressed. A 1920 x 1080 8-bit pixmap is 1920 x 1080 x 3, or about 6.2 MB, whatever the picture contains. Our 1600 x 1200 test pixmap was 5,760,017 bytes and came out at 50,274 bytes at the default preset — roughly 1% of the original. Treat the raw size only as the "before" figure; the "after" depends entirely on content and preset.

Why did my colours shift slightly?

Because a PPM cannot carry a colour profile. Its header is only a magic number, width, height and maxval, and the specification defines the samples against the ITU-R BT.709 transfer function. In practice tools including ours read and write those samples as sRGB, which shares BT.709's primaries and white point and differs only slightly in the transfer curve. If your pipeline worked in a wider gamut such as Display P3 or Adobe RGB, convert to sRGB before writing the pixmap — otherwise those numbers get reinterpreted rather than converted.

What happened to the transparency in my image?

There was none to lose. PPM stores red, green and blue samples and nothing else, so there is no alpha channel in the source. AVIF itself supports alpha through a separate auxiliary image item, but with an opaque pixmap going in there is nothing for it to hold. If your wider workflow needs transparency, carry it in PNG or the Netpbm PAM format rather than PPM.

Which browsers and applications can open the AVIF?

caniuse currently reports AVIF at 94.67% of tracked global browser usage: Chrome 85 and later, Firefox 93 and later, Safari 16.4 and later on desktop, and Edge 121 and later. The realistic gaps are Apple devices left on pre-2023 releases and older desktop image software that predates the format. For something that opens essentially anywhere, PPM to JPG is the safer export.

Why does my image tool write PPM in the first place?

Because it is the lowest-friction interchange format there is. Any program can write a Netpbm file with a printf and a byte dump, and any program can read one without a library. That makes it the natural scratch format between stages of a processing chain — but it is deliberately a working format, not a delivery format, which is exactly why compressing it at the end of a pipeline is the right move.

How are my files handled, and how long are they kept?

Your pixmap is uploaded over an encrypted connection and encoded on our servers. Files are deleted automatically after a few hours, there is no sign-up and no watermark, and nothing is shared or made public.