Extract Highlights from PDF

Highlighting a long PDF is quick; copying every highlight into your notes afterwards is not. This tool reads the highlight, underline, strikethrough and squiggly marks saved in a PDF, works out the text underneath each one, and collects them — with sticky notes, comments and replies — into Markdown, plain text or a CSV spreadsheet. Everything happens in your browser; the PDF is not uploaded.

How to use this tool

1. Choose one or more PDFs you have annotated.
2. Pick Markdown for note apps such as Notion or Obsidian, or plain text.
3. Group the results by page, highlight colour or annotation type.
4. Copy the export, or download it as a .md/.txt file or a CSV for Excel.

Formula

Each text-markup annotation stores rectangles (QuadPoints) over the marked text. The tool takes the PDF text pieces whose line overlaps a rectangle and keeps the characters whose centre falls inside it. Several rectangles (a highlight across lines) are joined with spaces.

Colour names are the nearest of yellow, green, blue, red, pink, orange, purple, grey and black to the colour stored in the annotation; the exact hex value is in the CSV.

Example

A 12-page article with 9 yellow highlights and 2 sticky notes gives a Markdown export with a section per page, each highlight as a quote (> text), a highlight's attached comment as a Note: line, and a CSV with 11 rows: file, page, type, colour, text, note, author and date.