Compress PDF
Make a PDF smaller, losslessly or down to a target size, by re-encoding its images on your device.
Compress PDF in 4 steps
- Open the PDF.
- Choose lossless compression, or enter a target size in MB.
- Start compression and watch the progress.
- Compare the new size with the original and save the result.
Questions and limits
No. PDF Studio has no upload server. Your files are opened, changed and saved inside this browser tab by JavaScript and WebAssembly running on your device. You can check it yourself: open your browser's developer tools, watch the Network tab while you use the tool, and you will see that no request carries your file.
Compressing to a target works by shrinking and re-encoding the images in the PDF. A PDF that is mostly text, vector drawings or embedded fonts has little to shrink, so the target can be unreachable. In that case you get the smallest file we could make, and we tell you it is above the target.
Lossless compression only repacks the file and does not change how it looks. Compressing to a target lowers image resolution and JPEG quality just enough to fit; text and vector graphics stay sharp, and transparent areas stay transparent.
No. Changing a PDF writes a new file, and that invalidates any digital signature it had. Sign the document again after editing it.
There is no upload limit, because nothing is uploaded. The practical limit is your device's memory: desktop browsers handle files of several hundred megabytes. On phones and tablets we warn you above about 200 MB or 1,000 pages.
Yes, after the first visit. The app and the processing engines are stored in your browser's cache, so the core tools keep working without a connection once they have loaded once.