PDF Looker Pro 2.0 — a PDF reader and annotator, written from scratch

Oct 18, 2026 - Chengxi Zhang - Release

The PDF Looker Pro window: thumbnails and an annotation list on the left, and a page carrying a typewriter note, a highlight, a standard stamp and a distance measurement. — The application as it is: a typewriter note, a text highlight, a standard stamp and a distance measurement, beside the list of annotations on the page. They are written into the PDF itself, so Acrobat or Preview shows the same marks.

I have released PDF Looker Pro 2.0, a desktop PDF reader and annotator for Windows (MIT, portable, no installer). Rendering is pdf.js; two things that had no ready-made component are implemented from the bytes up — a writer that puts annotations into the PDF so other readers see them too, and a whole-document rewrite that makes page editing possible at all.

Version 2.0 closes four areas of work. Reading: continuous scroll with page virtualisation, four view modes, fit-to-visible-area, a magnifier, printing with a page range. Document editing: rotate, delete, insert, extract, crop, reorder, merge another file in, and build a document from images. Annotating: eleven markup and shape types, six standard stamps, replies written as real /IRT threads, flattening, and an annotation summary. Search: results grouped by page, folder search across documents, and saved searches.

It also fixes a defect worth naming: an annotation written into a file could not afterwards be removed. The writer appended to the page’s /Annots without dropping what it had written before, so a deletion was undone by the next save and every save added another copy of every mark. That chain now has its own regression test.

Project page and download · Source on GitHub · Release notes

已发布 PDF Looker Pro 2.0：一个从零写起的 Windows PDF 阅读与批注工具。批注直接写进 PDF 文件（增量更新，不改动原始字节），页面编辑走整份重写路径，因此旋转、删页、合并都能真正落到文件里。2.0 同时修复了「存进去的批注删不掉」这一类缺陷——写入器过去只追加、不摘除上一次写入的对象。项目页与下载见上方链接，源码为 MIT。