PDFSyntax is a Python package that allows you to inspect the internal structure of PDF files without any dependencies. It uses a visualization approach that adds information and hyperlinks on top of uncompressed PDF data, making it easier to navigate between revisions and objects. The tool generates static HTML content that is interactive even with JavaScript disabled. Features include reverse indexing, page navigation, minimap, pretty-printing, object extraction, stream decompression, and more. You can try out a live demo of the tool’s output on their website. Keep in mind that encrypted files are not currently supported, and new features are in development.
https://github.com/desgeeko/pdfsyntax/blob/main/docs/browse.md