About this site

How the tools work

When you choose a file, the browser hands the page a reference to it. From there everything happens locally: images are decoded by the same engine that draws them on any web page, then redrawn into a canvas at a new size or re-encoded at a new quality. PDFs are handled by two open source libraries loaded into the page, one that reads documents and one that writes them. The finished file is assembled in memory and offered to you as a download.

At no point is your file transmitted. You can verify this: open the network tab in your browser's developer tools, run any tool, and watch that nothing leaves. Or simply disconnect from the internet after the page has loaded, and notice that the tools still work.

What this means for you

• No account, no email address, no queue and no daily limit.
• No file size cap beyond what your own device can hold in memory.
• Sensitive documents stay sensitive. Nothing is stored, because there is nowhere to store it.
• Large jobs are as fast as your machine, and no faster. A hundred-page PDF rendered at 300 DPI is genuine work.

The domain

pythonware.com was for many years the home of the Python Imaging Library, the package that taught a generation of Python programmers to open, resize and convert images. PIL's last release was in 2009, and the actively maintained successor is Pillow. The old documentation is kept in the archive for the people who still arrive looking for it.

The tools on this site are new work and share no code with PIL. The connection is one of subject matter: this domain has always been about moving pixels from one shape into another.

Corrections

If a tool gives you a wrong answer, or a form accepted a file this site said it would not, that is worth knowing about. The behaviour of upload validators varies more than any documentation admits, and the notes on these pages are written from observation.