Open Source Alternatives to Adobe Acrobat

Switching from Acrobat to Okular or Xournal++ mainly addresses the subscription itself — both cover annotating, marking up, and digitally signing PDFs at no cost, with no recurring Standard or Pro plan required. Okular is the closer match for general-purpose use, reading and annotating PDFs alongside several other document and ebook formats in one app. Xournal++ instead centers on pen and stylus input, layering handwritten notes and markup directly over a PDF background, which suits tablet users more than Okular’s typing-and-clicking annotation tools. Neither replicates Acrobat Pro’s redaction, direct text/image editing inside a PDF, or web form creation, so anyone relying on those specific paid features will still need Acrobat for that work.