How PDFolio Works
High-performance document processing without a single backend server.
PDF.js Thumbnail Engine
When you drag files into the studio, PDFolio utilizes Mozilla's PDF.js library running in an isolated background Web Worker. It parses the document xref table, builds visual page viewports, and rasterizes high-speed thumbnail cards onto HTML5 canvases without blocking the user interface.
PDF-lib In-Memory Mutation
For page organization, watermarking, page numbering, rotation, and merging, PDFolio uses pdf-lib. It operates directly on binary PDF object structures in RAM. Pages can be duplicated, spliced, rotated, and annotated with custom vector fonts without loss of vector clarity or text selectable attributes.
fflate Multi-Threaded Deflate
When downloading split page sets or image exports, PDFolio packages results using fflate—the fastest pure JavaScript compression engine available. It utilizes asynchronous chunks to create standard .zip archives directly in memory.
IndexedDB Local Job Ledger
Using idb, your browser keeps a lightweight, structured record of completed operations on your local device. If you accidentally close your browser window, your job summary can be inspected upon return.