Show HN: Collate – Offline AI PDF reader and chat for Mac (private, on-device) (opens in new tab)

I built Collate, a free Mac app that summarizes and chats with PDFs entirely on your device. No uploads, no rate limits, just open a file and ask questions. It highlights the exact passages it used and shows citations, so you can verify answers quickly.

Why: I wanted AI that feels like a normal app—fast, private, and not tethered to a cloud account—especially for long papers and reports.

How it works (high level): • Extracts text with native macOS frameworks (works best with text-based PDFs). • Chunks + indexes the doc locally for retrieval. • Runs a small LLM on Apple Silicon using on-device inference. • Maps answers back to page spans and auto-highlights them.

What’s new: share clean summary links (text only, optional), faster summaries, and a progress tracker that shows how much of the doc you’ve covered as you chat.

Known limits: macOS 13.5+ on Apple Silicon; large/scanned PDFs (pure images) work poorly without OCR; still polishing multi-PDF answers and edge cases.

Why: If AI is going to be an equalizer, it shouldn’t meter every question or upload private files. Collate runs on your device and removes the limits. What features would be the biggest unlock for you? Links: https://collate.one Happy to answer technical questions.