fast (default): pypdfium2 text extraction + pdfplumber tables + RapidOCR for scanned pages only. About as fast as reading the file (roughly 0.3-1s/page on a normal text PDF), priced near the market rate, and good enough for most RAG/LLM use. Docling's ML models never load. accurate: full docling layout analysis + TableFormer table-structure recognition. Much slower (roughly 15-70s/page on a 4 GB/1 vCPU worker) and priced higher (accurate-page + table charges), but reconstructs reading order, headings and complex table structure more faithfully - worth it for dense forms, multi-column layouts, or tables you need pixel-accurate. DOCX/PPTX/XLSX/HTML always use docling's fast native (non-ML) backends in both modes. Memory: fast mode runs fine at the default 2048 MB. Accurate mode needs 4096 MB; set it in the run options, or the run stops before charging anything.