SummitUp

Sum it up: select a passage for a sketch, or a term for a plain-English definition.

Highlight it. Understand it. SummitUp turns dense writing into a simple sketch and two clear sentences. Select a paragraph on any web page, click the pill, and get a hand-drawn diagram of what it actually means, plus an explanation short enough to remember. Select a single word instead and you get a definition, read in context. "Parameters" means learned weights in a machine-learning paper and function arguments in a Python tutorial. SummitUp reads the surrounding sentence and answers for the page you're on. Built for people learning something hard • Sketches that carry meaning, parts, sequences, cause and effect, comparisons. Not decoration. • Two sentences, 35 words, a hard ceiling, because an explanation you can't remember hasn't explained anything. • 148 built-in terms covering machine learning and API documentation, answered instantly and offline. • Knows when not to draw. If a passage has no structure worth diagramming, you get the explanation alone rather than three meaningless boxes. • Explain-only mode for when you just want the words. You bring the key SummitUp has no server and no subscription. You add your own API key from Anthropic, OpenAI or Moonshot, it stays in your browser, and you pay your provider directly — typically well under a cent per use. Nothing is sent anywhere except the text you select, to the provider you chose. Requires an API key from Anthropic, OpenAI, or Moonshot (Kimi). Without one, only the offline dictionary works.