I’m developing https://simplePDF.eu https://simplePDF.eu on my free time. It’s more of a PDF editor / annotator than viewer but it may suit your needs nonethel

I’m developing https://simplePDF.eu https://simplePDF.eu on my free time. It’s more of a PDF editor / annotator than viewer but it may suit your needs nonetheless: You can open multiple multiple tabs in your browser to view the same PDF at different chapters for example Some additional details: - entirely free - everything happens locally in your browser: the documents you load are never sent to the server