Highlight, then ask.

A PDF reader for Mac where every highlight can carry a conversation. Open a PDF, an arXiv paper or any web article, ask about a passage, and get an answer that cites its page, saved on the highlight, inside the file.

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macOS 14 or later. Free while in beta.

Chapter 3Remembering

We like to think of memory as a recording we can replay. It is closer to a retelling. Each time we recall an event, we rebuild it from fragments, and the rebuilt version is what we store again. Over the years the story grows smoother and more confident, even as it drifts from what happened.

This is why vivid memories feel so reliable, and why they so often are not. The details we are surest of are frequently the ones we have told most often, and each telling sands away a little more of the original.

None of this makes memory useless. It makes it something to be checked, the way a careful reader checks a source.

Psychologists who study eyewitnesses see the same pattern again and again. A witness questioned twice gives a firmer account the second time, not because they remember more, but because the first conversation has become part of the memory itself.

Explain

Recalling a memory edits it: you save the rebuilt copy, not the original. Repeat that often and a memory becomes confident but less accurate p. 42

Read with a question in the margin

Select
Pick a highlighter colour once, then select text the way you would with a pen.
Ask
Explain, Define, Simplify, Example or Counter-argument in one click, or type your own question.
Check
Answers cite pages like p. 42. Click to jump there; Glossa confirms the quoted words are on that page.

Every highlight keeps its conversation

The thread is saved inside your PDF, so it travels with the file and shows up in Preview and Acrobat too.

A highlighted passage in Glossa with its AI conversation and a page citation

Open any link

Paste a link with File › Open Link… (⇧⌘O). PDFs open as they are, arXiv papers arrive as their PDF, and blog posts and articles are saved as a clean PDF, ready to highlight and ask about.

Use the AI you prefer

Choose once in Settings. You can change it any time.

On your Mac

Apple Intelligence runs on-device and is free. No key, no account, nothing leaves your Mac.

Local models

Run any open model with Ollama or LM Studio. Works offline.

Your own key

OpenRouter, Anthropic, OpenAI or Gemini. Keys stay in your Mac's Keychain.

And everything a good reader needs

Charts and tables: Drag a box around a figure and ask. Glossa sends exactly that area to a vision model.
Ask the whole book: Questions about the full text, answered with page citations.
Book Notes: A study summary of everything you highlighted and asked.
One search for everything: Highlights, notes, chats and full text across your Library.
Emoji tags: Mark ideas, questions and favourites in the margin, then filter.
Scanned PDFs: On-device text recognition makes scans searchable and askable.
Comfortable reading: Night and Sepia pages, two-page view, and every book reopens where you left off.
Web articles and papers: Any blog post, article or arXiv link becomes a clean PDF you can annotate.
Export: Markdown, TextBundle with images, Anki flashcards, or straight into Obsidian.

Glossa never rewrites your PDF. It only adds your annotations, and it checks every save.

Questions

Do I need an API key?

No. On Macs with Apple Intelligence, Glossa uses Apple's on-device model for free. You can also run a local model with Ollama, or add your own key for stronger cloud models.

Is my reading private?

Glossa has no account, no analytics and no servers. On-device and local AI send nothing anywhere. With a cloud provider, only the passage you ask about is sent, to the provider you chose, after you agree. Read the privacy policy.

Can I read web pages, not just PDFs?

Yes. Paste a link into File › Open Link… and Glossa saves the article as a clean PDF with a link back to the original, so highlights, chats and page citations work the same way. The support page has a one-click bookmark for any browser.

Will Glossa change my PDFs?

Your file is never rewritten. Highlights are added as standard PDF annotations, so they also appear in Preview, Acrobat and other readers.

How much will it cost?

Reading, highlighting and AI chat will be free. A one-time Glossa Pro purchase will unlock Book Notes, figures and whole-book questions.

Try the beta today

Free download for Macs with macOS 14 or later. On first open, macOS asks you to confirm it; the download page shows how.

Download Glossa 0.9 beta

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