Explainpaper

Explainpaper is built around one interaction: you highlight text, and AI explains it in the context of the entire paper. That specificity is the product. Instead of summarizing a whole PDF and hoping the summary covers the part you were stuck on, you aim at the sentence that lost you, and the explanation is generated with awareness of the surrounding paper rather than as a generic gloss. You can tune how simple or technical the explanation is, which matters when the same paragraph needs a beginner framing one day and an expert framing the next, and you can read explanations in 50+ languages, so a non-native English speaker can work in their native language without losing the paper's meaning. The second layer is chat. You ask questions about the paper and the answers are grounded in the paper's actual content — the site's claim is that answers come from the document, not from general knowledge — and responses can cite specific sections so you can jump to the relevant part and check the reasoning yourself. Follow-up questions let you drill into a topic rather than accepting a single explanation. Beyond that, auto-generated insights give you a smart outline of the paper, extract the key points, and map how concepts relate, which is useful when you want to decide whether a paper is worth a full read before committing. What sits behind the paywall is the power tier: advanced AI models, full-paper summaries, saved highlights and explanations, and Math Explain for formulas and figures. The free plan runs on basic AI models, which is fine for straightforward prose but can flatten genuinely technical concepts — the tradeoff is that free gets you the core mechanic with no usage cap on highlight explanations. Where it fits: literature review, coursework, self-directed learning in unfamiliar fields, and any reading where jargon is the barrier rather than access to the paper. Where it doesn't: it is a reader, not a reference manager, so if your real need is organizing and citing a library, Zotero is the tool for that job — Explainpaper imports from Zotero rather than replacing it. It also assumes PDFs and an internet connection. If you need unlimited advanced-model summarization without paying, that isn't what the free tier provides; the free tier gives you the explanation loop on basic models.