How the PDF compressor works
The compressor reduces file size by re-encoding the images inside your PDF. When you upload a receipt or invoice, Receipt Caker renders each page in your browser, re-saves it at a lower resolution and image quality according to the level you chose, and rebuilds the document from those lighter pages. Because scanned and photographed receipts are mostly image data, this is where the size savings come from — the file that was too big to attach comes back small enough to send.
You stay in control of the trade-off. A lighter level keeps pages sharper for a smaller reduction; a stronger level squeezes harder when you need to hit a strict limit. After each pass the tool reports the exact before-and-after size and the percentage saved, so you can rebuild at a different setting if the first result is not small enough — or is smaller than it needs to be.