JPG to PPM Converter
You are feeding pictures to a script, a classroom exercise or a small program that reads plain pixel data, and it understands PPM but not JPG. This converter writes a binary PPM from your JPG on your own device. It is a simple, uncompressed format, which is exactly why those tools like it.
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How to convert JPG to PPM
- Add your JPG files by dropping them, clicking the drop zone or pasting.
- The output format is already set to PPM. Adjust quality or size if you need to.
- Press Convert and compare the original and new size for each file.
- Download each file or all of them as a ZIP.
When to convert, and when not to
- A program you wrote, or a course assignment, reads PPM because the format needs no library to parse.
- A command-line tool in your pipeline expects the Netpbm family of files.
- You want to inspect raw pixel values with a text editor or a few lines of code.
- Do not use it for sharing pictures with people: the files are huge and few viewers open them.
What changes
- The file is a short text header followed by raw red, green and blue bytes for every pixel.
- There is no compression, so the size is roughly three bytes per pixel plus the header.
- PPM has no alpha channel, and the Background colour option decides what fills any transparent area.
- Camera details and other metadata are not written, and phone photos are turned upright first.
- The Quality slider is hidden, because PPM has no lossy setting.
What is inside a PPM file
A PPM written here starts with a few readable characters: the letters P6, the width and height, and the maximum colour value, which is 255. After that single header comes the picture itself, one red, one green and one blue byte per pixel, row by row from the top left. There is nothing else in the file.
That simplicity is the point. You can read a PPM in a few lines of almost any language, and you can write one by hand while testing an idea. It is often used in teaching because students see exactly how an image is made of numbers.
Why the files are so large
Since nothing is compressed, the size follows directly from the pixel dimensions: width times height times three, plus the header. A photo that fits in a small JPG can become a PPM many times heavier. That is normal and does not mean the conversion went wrong.
If your script does not need the full resolution, use the Resize option to reduce the picture first. Smaller dimensions give a smaller file, which also makes test runs faster and keeps memory use down.
Checking the output
Many image viewers do not open PPM, so do not be surprised if a double click does nothing. Open it in a program that supports the Netpbm formats, in a graphics editor with a plug-in, or simply load it in your own code and print the first few values.
The JPG compression flaws that were already in your photo are kept as they are. PPM stores the decoded pixels, so blocky patches remain, and the conversion cannot improve them. When you are ready, add all your JPG files at once and download the results as a ZIP.
Privacy: your files stay on your device
- The tool decodes, resizes and encodes your pictures with your browser. The files are never sent to a server.
- To check it yourself: open the browser developer tools (F12), open the Network tab, convert a file, and look for any request that carries your image. You will see none.
Frequently asked questions
Which kind of PPM does this write?
Binary PPM, known as P6, with 8 bits per colour and a maximum value of 255.
Why will my picture viewer not open it?
Many viewers do not support PPM. Use a Netpbm-aware program, an editor with PPM support, or read it from code.
Is transparency kept?
No. PPM has no alpha channel. Any transparent area is filled with the Background colour you choose.
Why is the file so big?
It stores three bytes for every pixel with no compression. Reduce the pixel size with Resize if you need a smaller file.
Can I get a text-based PPM (P3)?
No. The converter writes only the binary P6 variant.