PDF Owl now supports hierarchical ToC generation

It’s been over two years since we first introduced PDF Owl — a tool that generates tables of contents using on-device AI models. With the new 1.4 release, PDF Owl can now detect the hierarchy of chapters, sections, and subsections, automatically building a structured, hierarchical table of contents. As always, everything runs entirely on your device, and no data is ever sent to the cloud. It does not rely on the OCR layer, font size; everything is done using computer vision. Hence, it works for many languages and for poorly scanned PDFs as well. Download from the Mac AppStore: https://apps.apple.com/us/app/pdf-owl/id6450437117 Read more on the app's website: https://138street.com/pdf-owl/ Problem PDF files do not always include a table of contents (TOC, also known as bookmarks or an outline in different PDF apps). This is particularly common with scanned documents, where the TOC is often missing or of poor quality. A well-structured TOC is essential for navigating large files (e.g. books), as manually scrolling through hundreds of pages can be tedious. While many PDF applications allow users to create a TOC manually, few provide a reliable way to generate one automatically. Comparison For ToC generation feature for PDF files: Python scripts like pdf.tocgen and tocPDF: the scripts use font attributes to deduce headings, which is not very reliable in practice, especially for poor scans. PDF Owl uses computer vision and modern transformers models for analyzing page layout. You can use LLMs like Claude, but there is no end-to-end solution, so performance will be varied; also the tokens might be expensive for large files. PDF Owl runs everything on your device and hence, unlimited in usage. As for PDF reading comparison, there are too many and the best reference is PDF Readers comparison sheet from r/macapps. PDF Owl's character in this large selection of apps is being reader focused (not pretending to be editor because PDFs are made for reading and inherently hard to edit), minimalism, and providing essential reading features without being overblown. Price The app is free of charge for reading & annotating, and the ToC generation function is $2/month or $30 for a lifetime license. We hope the PDF community enjoys this update. Happy PDF reading!