Runs in your browser
An installable web app (PWA). Open app.lectorium.com.br on a tablet, phone or desktop.
Annotate. Write.
Think better.
An academic workspace that runs in your browser: read and annotate PDFs by hand, write in ABNT, connect ideas in mind maps and use the Kalaki AI with your own key. It works offline, and your files stay with you.
Local first
Files, annotations and maps stay on your device. The cloud only steps in when you decide.
Rust/WASM core
OCR, indexing and the maps engine run off the main thread, staying smooth even with heavy material.
The product
A quiet place for intellectual work.
Reading, writing, visual structure and AI in a single flow, without turning study into a pile of loose tabs. PDFs, documents, mind maps and images open in the same workspace.
Tablet · Library
100%
local control
Phone
Capabilities
From raw text to organized idea.
Instruments connected by a single principle: cut the friction between reading, understanding and producing.
Reading and annotation
The PDF stops being a closed page.
Highlight, write by hand, add notes, stamp images and search text. OCR (via Gemini) makes even scanned documents searchable.
Mind maps
Think in relationships, not just pages.
An infinite canvas with the Stella, Arbor and Orbis models, color-coded nodes and a navigation radar. AI-assisted generation and expansion.
Kalaki AI
Kalaki reads what you're looking at.
The built-in AI summarizes, questions and structures your material with your own Gemini key and no token packs.
Library and themes
Your collection, your way.
Organize files locally, sync with Google Drive or Dropbox whenever you want, and switch the look with themes such as Kinnabari, Aether and Nox.
Experience
Every tool takes its proper place.
Three surfaces of the product. The interface changes role without changing its language.
01 / Reading
A reading surface that respects the document.
The PDF owns the screen. Ink, highlighter, notes, stamps and OCR stay close by, but stop competing with the content.
- Ink, highlighter, notes and image stamps
- OCR via Gemini, with no detour through Lectorium servers
- Search and page-by-page navigation
02 / Structure
An infinite canvas for organizing complex ideas.
Turn readings and concepts into visual networks. Nodes, connections and a navigation radar keep the big picture without losing the detail.
- Stella, Arbor and Orbis models
- AI-assisted generation and expansion
- Smooth navigation across large maps
03 / Writing
Academic documents inside the same flow.
The editor formats in ABNT, handles citations and exports .docx, keeping writing, review and references right next to your library.
- ABNT academic formatting and citations
- Exports .docx without relying on the cloud
PDF reader
Mind maps
ABNT editor
Connections on demand
The cloud is a choice, not the center of the product.
Connect Google Drive or Dropbox to open, organize and sync files whenever it makes sense. Without a connection, the workspace stays whole on your device.
Understand how data is handledDrive and Dropbox, when you ask
Permissions limited to the flow you choose- 01 Open files you've selected yourself.
- 02 Save changes and new documents.
- 03 Resume the sync queue after reconnecting.
- 04 Revoke access at any time.
Privacy as architecture
Your files don't have to pass through us.
Lectorium is designed to keep the data under the service's control to a minimum. Documents stay on your device (IndexedDB + OPFS) or in the providers you choose to connect.
Documents
On your device, or in your Drive/Dropbox. Never on a server of ours.
AI and OCR
They use your key and talk straight to Google Gemini, never through us.
Transparency
The policy and terms can be read before any use.
Frequently asked questions
What matters before you start.
How Lectorium works today, where your files stay and when AI enters the flow.
-
Do I need to sign in with Google?
Yes. Access to Lectorium uses Google sign-in. After sign-in, the workspace remains local-first: your documents stay on the device or in the providers you connect. -
Does it work on tablets and phones?
Yes. It is a PWA: it opens in the browser and can be installed from Chrome or another compatible browser menu. The main experience is tablet-first, but it also works on phones and desktops. -
Do my documents live on Lectorium's servers?
Not by default. Documents stay in local storage on your device. If you connect Drive or Dropbox, they stay with those providers. Lectorium does not keep a central copy of your files. -
How do the AI and OCR work?
AI and OCR are optional. You provide your own Google Gemini key and, when you use those features, the required content is sent directly to Google. Lectorium does not sell token packs and does not use its own server to mediate that processing. -
Is Lectorium free?
Yes. The core reading, organization and local study features are free. Premium features and themes are in preparation and will be clearly marked before any charge.
Get started now
Study demands attention.
Software shouldn't steal it.
Open Lectorium in your browser and bring your library into one place. Offline, with Google sign-in.
Open Lectorium