I Built a Study-Notes Summarizer in the Browser — No AI API, Just Word-Frequency Scoring

I built a study-notes summarizer in the browser — no AI API, just word-frequency scoring

Finals season is brutal. You have 40 pages of lecture notes, 3 hours left, and a brain that stopped cooperating at page 12.

What if you could paste all those notes and instantly get the 5 sentences that actually matter?

That's what I built today — a fully browser-side study-notes summarizer. No OpenAI key. No backend. No data leaving your machine. Just pure vanilla JavaScript and a technique called extractive summarization.

Here's how it works, explained like you're a person and not a research paper.