2026 年最佳 ChatPDF 替代品
The free plan's two documents a day is the usual trigger for looking elsewhere, and heavy readers also find that ChatPDF only knows the files you upload — it cannot search a literature corpus for papers you have not found yet. PDF.ai is the closest like-for-like swap, adding OCR for scanned documents and shared team libraries. SciSpace goes further in the research direction, pairing PDF chat with literature search and cross-paper extraction tables. People who already pay for ChatGPT often just upload files there instead, accepting weaker page-level citations in exchange for one less subscription.
横向对比一览
Research workspace that chats with papers and adds literature search and extraction tables
Literature search with cross-paper extraction tablesCopilot reader that explains passages, tables and equations in plain languageChat with any PDF, with unlimited chats on paid plans最适合: Working across many papers, not one file
General AI assistant that accepts PDF uploads on its paid plans
Conversational answers across writing, research and codingImage understanding, file uploads and voice on paid plansCustom GPTs and shared conversations最适合: People already paying for a general assistant