Private PDF and EPUB annotations with linked notes

Keep the source and the thinking together

Reading often produces two different kinds of information: a precise mark on a page and a longer explanation of why that passage matters. SovaSpace supports both without forcing the entire note into a small annotation popup.

PDF and supported EPUB layouts can carry visual marks linked to rich-text reading notes. The note can include structured text and supported images, while the mark provides a direct route back to the relevant page or region.

Separate encrypted annotations instead of rewritten documents

Annotations are stored in a separate encrypted data file—sometimes called a sidecar—rather than being burned into or written back over the source document. This keeps the imported document intact and lets SovaSpace protect the annotation data with the rest of the workspace.

Supported visual tools include region highlights, lines, pen strokes, rectangles, circles and bookmarks. Geometric marks can be placed on scanned pages even when the document has no usable OCR text layer.

PDF behavior

PDF pages retain their document-defined geometry, so a mark can be associated with a stable page and coordinate region. Complex PDFs, malformed files, unusual fonts and embedded media can still render differently across engines and platforms.

SovaSpace does not claim to edit the internal structure of every PDF or reproduce a professional publishing application. The focus is private reading, visual markup and linked thinking.

Supported EPUB layout

Reflowable ebooks are harder to annotate consistently because line breaks can change with the viewport. SovaSpace uses a fixed 800-pixel layout and a 1,132-pixel virtual-page definition for its supported EPUB workflow so page positions and annotation coordinates can remain stable across supported clients.

That is an application layout choice, not a promise to reproduce every publisher's typography, script, interactive element or digital-rights system exactly.

Search states should be honest

For supported PDF and EPUB search, SovaSpace distinguishes a confirmed empty result from a search that could not be completed. “No result” should mean the searchable material was actually checked, not that a parser failed silently.

Privacy and portability

Source documents, annotations and linked notes are protected according to the SovaSpace storage model. Exporting a document or note to plaintext moves that copy outside the encrypted workspace and into the security boundary of the destination file and application.

A private annotation system protects the stored note; it cannot make a publicly obtained document private or override the rights attached to that document.