Open-source Zotero plugin Mktero turns paper PDFs into linked Markdown

On October 30, 2026, the author of Mktero posted on V2EX to introduce this open-source Zotero plugin. Mktero is an extension for Zotero 7–10, released under the MIT license. The author described several frustrations that motivated the work: in two-column PDFs, finishing the left column means scrolling back to the top to find the right one; equations and tables are hard to read in small windows and come out garbled when copied; and verifying a number in a paper means flipping back through the PDF page by page. Existing PDF-to-Markdown tools only solve part of the problem, the author wrote, because they produce a Markdown file and a PDF file that are not linked, so notes and highlights do not line up and citations cannot be checked against the original text before use.

Mktero works by reflowing the paper into a single continuous column of body text inside a Zotero tab, triggered by right-clicking the PDF and choosing "Use Mktero to read Markdown." Two-column layouts are rearranged in reading order. Equations, tables, figures, citations, and footnotes are preserved, with equations rendered by KaTeX, while journal mastheads, headers, and page numbers are hidden. Each paragraph, equation, table, and figure keeps its page and region mapping, so an "View in PDF" action jumps back to the exact page and position. Highlights made in the Markdown are the Zotero PDF annotations, and highlights that already exist in the PDF also appear in the Markdown. The plugin additionally supports proofreading OCR errors in paragraphs, headings, and table cells, with corrections stored separately so they do not alter the cached conversion result. Display math can be copied as LaTeX, and tables can be copied as Markdown or other formats. So far only this single introduction has been published, and no follow-up developments have been reported.