Privacy policy
Diop · Last updated October 25, 2026
The short version: Diop has no accounts and no server that stores your files. Your papers, books, highlights and notes stay on your device. Nothing is sold, and nothing is tracked.
What stays on your device
Files you open, your reading place, highlights, bookmarks, notes, summaries and settings are kept in your browser's storage on your device. Clearing your browser or app data removes them. Diop's maker cannot see them.
Diop AI (free, built in)
Unless you connect your own AI, summaries, translations and teardowns use Diop AI. When you ask for one, the passage is sent from Diop's site to OpenRouter, which runs it on Google's Gemini, or on free open models when Gemini is busy. Some free model providers are in China, and free models may keep prompts to improve their service. Don't use Diop AI for text you need to keep private. Connect your own AI instead.
Scanned pages and comics
When you open a PDF of scanned pages, such as a comic or manga, Diop sends a picture of each page to Diop AI as you read, so it can find the text in the bubbles. This happens on its own, even if you connected your own AI. Diop keeps the text it finds only on your device; the pictures go through OpenRouter like any other Diop AI request. Don't open scans you need to keep private.
Your own AI
You can instead connect an AI service (Claude by Anthropic, ChatGPT by OpenAI, Gemini by Google or Grok by xAI) with your own API key. Your key stays on your device. When you ask for a summary, the text of that paper or book is sent from your device straight to the service you chose, under that service's own privacy terms. Nothing is sent until you ask.
Translation
When you translate a passage, Diop first uses your browser's built-in translator, on your device, if it has one. Otherwise the passage is sent to the AI service you connected, the same way as a summary. Nothing is sent until you tap Translate.
Tapping a word
When you tap a word, Diop looks up English words in the free Dictionary API (dictionaryapi.dev); only the word is sent. The sentence around it goes to your AI (Diop AI or the one you connected) to explain the word in context.
Opening links
When you open a link, Diop fetches the page or file through its own site, the same way a browser's reader view would, and stores nothing on a server. If that isn't available, it may ask Jina's public reader (r.jina.ai) to fetch the page instead, or a download proxy you set up yourself in Settings.
Reports
If you report a summary, Diop sends the reason you pick, any note you write, the AI service and model used, and the title of the paper. It is used only to review the report. No other data is attached.
Hosting
Diop's website is hosted by Netlify, which handles basic request information (such as IP addresses) to serve the site, under Netlify's privacy policy. Diop adds no analytics, ads or trackers.
Books and pictures
The books on the shelf come from Project Gutenberg. The covers and paintings are in the public domain, via Wikimedia Commons. Opening a shelf book downloads it from Diop's own site.
Children
Diop is not directed at children under 13 and does not knowingly collect any personal information from anyone.
Changes and contact
If this policy changes, the date above will change too. Questions: open an issue on GitHub.