Intelligent document processing (IDP) combines optical character recognition, machine learning, and increasingly large language models to transform unstructured documents into structured, validated data that flows into downstream systems, addressing data locked in invoices, contracts, forms, and reports that is otherwise extracted manually, re-keyed inaccurately, delayed, and invisible to analytics. The IDP market in 2026 spans established enterprise platforms that have processed millions of documents for Fortune 500 clients for two decades, developer APIs integrable in an afternoon, and open-source libraries built for feeding LLM applications. The guide covers 32 tools across six categories, with the right tool depending on what is processed, how much, who builds and maintains the solution, and what systems the extracted data must flow into. Among enterprise IDP platforms, ABBYY Vantage treats documents as a skill, using pre-trained, reusable AI models called "Document Skills" to handle specific document types so teams can deploy and retrain processing logic without writing code; it has over 30 years of OCR and ML investment behind it. Its features include pre-built and custom Document Skills, a marketplace of 150+ ready-to-use skills covering invoices, contracts, IDs, and medical forms, a low-code Skill Designer, confidence scores and human-in-the-loop review queues, native connectors to SAP, Salesforce, ServiceNow, and major RPA platforms, and process analytics and SLA monitoring dashboards. It is best for large enterprises with diverse document portfolios needing governance,