Integrated Reader

Polar has an integrated reader for all uploaded documents. The reader supports EPUBs, PDFs, and webpages (captured through the Chrome extension). Any annotation, highlight, or comment created in Polar is captured into your annotation repository.

Setting up your reader

You can personalize your reader across several areas - dark mode, PDF handling of dark mode, EPUB text width, automatic position resume, and auto-pagemarks. You can adjust all those items in your settings

Polar supports light and dark mode. Your global setting is automatically adopted for the reader. For PDFs, you can decide how dark mode is handled - from full color inversion, to grey scale, to keeping the original colors of the file.

In addition, Polar allows you to automatically resume your reading position if you turn the feature on. For this, you need to use pagemarks to mark your reading position. Pagemarks can be set manually by right-clicking anywhere in the file. Alternatively, you can also turn on auto-pagemarks which will automatically update your reading positio in the background.

Managing the file in the reader

In the top right of the reader, you can manage your file the same way you can manage it in the document repository. This includes, tagging, flagging, archiving, opening and copying the original URL.

In addition, you can set the number of columns for a file there. Many research papers are written in a two-column format. If this is not setting is not defined for the document, it can mess up the order of annotations for example.


The reader also provides an outline of the document, assuming the document includes one. By default, outline view is disabled. You can turn it on at the top left of the reader or by pressing [.

Reading features

Polar's reader supports state-of-the-art reading features, including text highlights, area highlights, and pagemarks. Please note, area highlights are currently not available for EPUB and captured web pages.

Polar supports multiple features for your annotations. This includes, direct edits, comments, flaschards from text highlights, automatic flashcards using AI, color changes, and tags for annotations to build a networked knowledge base.

When creating flashcards manually, the annotation text is automatically becomes the back of the card. Both front and backend can be edited of course.

You can also create flashcards in only one click using the AI flashcard feature. This feature automatically generates both question and answer from a text highlight using GPT-3. See an example below

Polar AI flashcards

Pagemarks allow you to closely track your reading progress. We support different types of pagemarks - specifically pagemarks from the very beginning of a doc (Pagemark to current location) and pagemarks from a specific page to your current location (Pagemark from Page to Current Location). The latter is currently only available for PDFs. In addition, you can also label pagemarks. For details on pagemark, see more here.

Annotation Sidebar

The annotation sidebar in on the right in the reader shows the list of highlights, comments and flashcards in that document. This is where you can work with your annotations

To view your annotations across all documents, use the annotation viewer in Polar.