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Read PDFs with Highlights, Ink, and Notes on Shelf

Shelf treats every uploaded PDF as a first-class document: color highlights, pen markup, text selection, and notes that stay attached to the page.

12 min read
fundamental-rights.pdf

Article 14 — equality before law

Highlight · Pen · Schedule

One PDF per page, streamed efficiently

When you upload a PDF, Shelf stores the full file once in cloud storage. The reader uses presigned URLs and HTTP Range requests so PDF.js can fetch only the bytes it needs — you are not waiting for a entire 200 MB file before page one appears.

After the first open, Shelf caches PDF bytes in IndexedDB (LRU, roughly five documents / 80 MB) so reopening the same paper feels instant, even on slower connections.

fundamental-rights.pdf

Article 14 — equality before law

Highlight · Pen · Schedule

Highlighting and notes

Select text on HTML notes or use the highlight toolbar on PDFs. Pick yellow, green, blue, or pink — colors persist on the page for later revision. Click a highlight to attach a note or remove it.

PDF pen mode supports small, medium, and large stroke sizes with optional auto-straightening for cleaner diagrams and underlines.

constitutional-amendments.pdf

Basic Structure doctrine limits Parliament's power to amend the Constitution beyond its core identity.

Kesavananda Bharati (1973) established that certain features cannot be destroyed by amendment.

Study AI

Explain this highlight

The Basic Structure doctrine means amendments cannot alter the Constitution's essential character.
Short notes

Reading comfort

Night mode inverts page bitmaps for late sessions. Scroll position, zoom, and current PDF page restore when you return — locally and, when signed in, synced to your account so another device picks up where you left off.

  • Keyboard shortcuts for page navigation in the reader
  • Schedule reading creates a planner task linked back to the page
  • Undo for recent PDF page deletes within a session
Shelf — Upload

Drop your PDF here

Parsed text or original PDF view

Parsed

Highlight & Study AI

Original

View as PDF

Why highlights matter for Study AI

Highlights are not just cosmetic. When you ask Study AI from the reader panel, selected text becomes context for the answer. Mark the paragraph you care about, open Ask AI, and get an explanation grounded in that exact passage from your upload.

fundamental-rights.pdf

Article 14 — equality before law

Highlight · Pen · Schedule

Parsed text vs original PDF view

Choose parsed mode when you want selectable text, highlights that export cleanly, and Study AI that reads the same words you see. Choose original PDF when the publisher layout — columns, footnotes, scanned diagrams — matters more than copy-paste.

You can switch modes per page without re-uploading. Processing runs asynchronously after upload; the reader shows progress and opens as soon as bytes are available, then enriches when HTML is ready.

constitutional-amendments.pdf

Basic Structure doctrine limits Parliament's power to amend the Constitution beyond its core identity.

Kesavananda Bharati (1973) established that certain features cannot be destroyed by amendment.

Study AI

Explain this highlight

The Basic Structure doctrine means amendments cannot alter the Constitution's essential character.
Short notes

Highlight colors and meaning

Use colors consistently: yellow for definitions, green for case holdings, pink for doubts to revisit. Highlights persist per page and sync with your account — reopen tomorrow and your markup is exactly where you left it.

Selected text powers Ask Study AI (⌘L): the model receives your highlight as primary context, so explanations stay tied to the passage you marked.

Shelf — Upload

Drop your PDF here

Parsed text or original PDF view

Parsed

Highlight & Study AI

Original

View as PDF

Pen, eraser, and sketch overlays

On supported pages, draw directly over the document for quick arrows, circles, or handwritten margin notes. Pen mode disables global keyboard shortcuts so keystrokes never jump you out of the reader while you annotate.

Sketch notebooks are separate page types with ruled backgrounds — ideal for diagrams that do not belong on top of a PDF.

fundamental-rights.pdf

Article 14 — equality before law

Highlight · Pen · Schedule

Sidebar, outline, and navigation

Toggle the library sidebar with ⌘B to jump collections without leaving the reader. Arrow keys flip PDF pages; typed page numbers work when you know the exact jump.

Long judgments and textbooks benefit from split view: keep the index or a second PDF open beside the main passage — covered in our workspace article.

constitutional-amendments.pdf

Basic Structure doctrine limits Parliament's power to amend the Constitution beyond its core identity.

Kesavananda Bharati (1973) established that certain features cannot be destroyed by amendment.

Study AI

Explain this highlight

The Basic Structure doctrine means amendments cannot alter the Constitution's essential character.
Short notes

Performance and offline reopen

Large PDFs stream with range requests — you do not wait for the full file before page one renders. Reopen uses an IndexedDB byte cache on your device so repeat visits feel instant even on slow networks.

Install Shelf as a PWA for an app-like reader chrome with less browser UI distraction.

Shelf — Upload

Drop your PDF here

Parsed text or original PDF view

Parsed

Highlight & Study AI

Original

View as PDF

From reading to revision

Export highlights mentally into Study AI threads: ask for short notes from today's yellow marks, or a mind map linking three cases you highlighted this week.

Link planner tasks to the exact page so Friday's calendar block opens the PDF with highlights already in place — no hunting through folders.

fundamental-rights.pdf

Article 14 — equality before law

Highlight · Pen · Schedule