About Folio
A practical document utility for turning photos and files into organised PDFs — and for cleaning up PDFs you already have.
Your files stay on your device
There is no upload step and no server-side processing. Images are decoded, pages are rendered and PDFs are written entirely inside this browser tab. Closing the tab discards everything.
PDF pages are preserved, not re-photographed
When you reorder, rotate or merge PDF pages without editing their pixels, the original page is copied into the new document. Text stays selectable and vector graphics stay sharp. Pages are only rasterised when you crop, straighten or apply a readability mode.
Built for large batches
Thumbnails render lazily and at a reduced resolution, each source is decoded once and cached, and full-resolution work happens only during export. Filters and perspective correction run in a Web Worker so the interface stays responsive.
Honest about limits
Edge detection for scanned pages is a conventional gradient analysis, not a learned model — when it is not confident it says so and hands you a manual crop tool. Office-document conversion is not available because it cannot be done reliably in a browser.
What it is built on
- pdf-libWriting and manipulating PDF files
- pdf.jsRendering PDF pages to canvas
- dnd-kitPointer, touch and keyboard drag-and-drop
- Canvas 2D + Web WorkersImage decoding, filters, perspective correction
- heic2any / UTIFHEIC and TIFF fallback decoding
Camera access
The camera is requested through the browser's standard permission prompt and the video stream is never recorded or transmitted — individual frames are captured to a canvas when you press the shutter. Camera access requires HTTPS, or localhost during development. If permission is denied, every feature remains usable by adding files from your device.