Open-source Readwise alternatives

Karakeep, previously named Hoarder, is a self-hostable app for saving everything you want to keep: links, short notes, images and PDFs. It automatically fetches titles, descriptions and images for links, and its AI features can suggest tags and write summaries, including with local models served by Ollama, which suits people who like to hoard data privately.

Saved content is sorted into lists that others can collaborate on, and search covers both full text and semantic meaning. Further features include OCR for extracting text from images, a rule-based engine for custom handling, highlights, bulk actions, SSO, automatic import from RSS feeds, and archiving of full pages and videos to guard against link rot. A CLI and official skills make it usable by LLM agents, and a REST API supports other clients.

You can capture content with Chrome, Firefox and Safari extensions, and there are iOS and Android apps with offline reading. Karakeep is AGPL-3.0 licensed and built with TypeScript, Next.js and React Native. It suits people replacing read-it-later services and bookmark managers with something they host.

Zotero is a free tool for managing research. It collects references as you browse the web, organizes them into collections with tags and saved searches, and helps you annotate, cite and share them. It is available for Mac, Windows, Linux, iOS and Android, and the source code in this repository is open.

A browser connector senses research material on sites it recognizes and saves it with a click. Citations and bibliographies can be generated for any text editor and directly inside Word, LibreOffice and Google Docs, with support for over 9,000 citation styles. A companion web tool, ZoteroBib, creates quick bibliographies without installing anything.

Syncing across devices is optional, and synced data can also be reached from a web browser. Libraries can be shared in groups, for co-writing a paper, distributing course materials or building a collaborative bibliography, with no limit on how many people join at no cost. The site also offers paid storage upgrades for synced files.

Memex is a browser extension from WorldBrain for curating, annotating and discussing valuable content and ideas on the web, whether you work as an individual, a team or a community. It is available as an extension for Chrome and Firefox and focuses on research and note-taking from the pages you read.

The repository topics emphasize annotations and full-text search, so saved pages and your highlights and notes can be found again later. The product's homepage also states that Memex exposes its dashboard actions through the Model Context Protocol (MCP), with a discovery manifest and a gateway that returns matching actions on demand, so AI tools can work with it.

The code is written in TypeScript and is public on GitHub, but the repository metadata does not give a license, so check the project terms before reuse. The extension runs inside your browser, and sharing and discussion features depend on the vendor's own services.