Explainpaper takes an uploaded academic paper and explains passages on demand: highlight the text that stopped you and get an explanation of that specific piece. It reports over 400,000 researchers using it.
Highlight-to-explain is a better interaction than summarising the whole paper, and the difference matters. A summary tells you what a paper claims, which you often already know from the abstract; what actually blocks a reader is one dense paragraph, an unfamiliar notation, or a method described in terms borrowed from another field. Being able to point at that and ask keeps you inside the paper rather than replacing it with a précis.
It is free to try. The honest limitation is one to hold firmly if you are reading outside your own field: an explanation can be fluent and subtly wrong, and you are least equipped to notice precisely where you most needed the help. Use it to get moving through a paper, and verify anything you intend to rely on or cite.
