Dev tools · alternatives · 2026
24 alternatives to Theorem – Offline PDF/ePub reader that writes highlights to Local Vault
Read PDFs, EPUBs, and RSS feeds offline. Highlight, draw, and annotate — then sync to Obsidian or Logseq as plain Markdown. Open source. No cloud. No subscription.
Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes.
- 1
ReadHere▲146Lightweight PDF & EPUB reader in your browser
Jun 2026 · readhere.app · its alternatives →
- 2
Converts some webnovels to epub format. Contribute to maoserr/epublifier development by creating an account on GitHub.
2024 · github.com · its alternatives →
- 31A
2022 · 1paragraph.app · its alternatives →
- 4
Hi HN, Nick here. We’re launching OpenKnowledge (https://openknowledge.ai/), a “what you see is what you get” markdown editor that has direct integrations with Claude, Codex, and other agents. Available as MacOS app or Web UI+CLI. Fully free/local and OSS. We built this because we wanted a Notion-like experience for writing and sharing markdown files across our team. Obsidian is the best alternative we tried, but found it doesn’t have a true WYSWIG UI and it didn’t integrate well with Claude/Codex outside of community plugins. So we built OpenKnowledge. It takes…
Jun 2026 · github.com · its alternatives →
- 5
Hey HN, cofounder of Readwise here. We've been working on this cross-platform reader app for about 2 years, excited to finally share it in public beta. Probably the most notable thing that makes Reader unique is that it supports almost any content type you could want to save/read/highlight: * web pages * emails/newsletters * PDFs * ePubs * twitter threads * youtube videos (with transcripts) * RSS feeds With all of your knowledge content in one place, we built powerful reading and highlighting, as well as a bunch of novel triage/organization features, so you can actually…
2022 · readwise.io · its alternatives →
- 6
Flowershow▲174I'm Rufus, one of the founders of Flowershow. We love markdown and use it everywhere from making websites, to docs, to knowledgebases. Plus AI splits it everywhere now. Got tired of the framework/config/deploy overhead every time we wanted to share a file or put a site online. So we built the thing we wanted. Files in. Website out. "Vercel for Content" is our aspiration - make deploying (markdown) content as fast, seamless and easy as Vercel did for JS. Command line plus you can connect to github repos, use Obsidian via plugin, or drag and drop files. npm i -g…
Mar 2026 · flowershow.app · its alternatives →
- 7
Burner Note▲222In 2021 after getting thoroughly sick of Privnote, i built "Burner Note". Even though i didn't promote it in anyway other than a post here and a post on reddit, it ended up getting about 7000(ish) unique users per month. I kinda let it die about 18 months ago but i've resurrected it with some big upgrades. Most botable the app is now truly end to end encrypted (previously was just server side), and I've added dark mode as well as a few other bells and whistles. Feedback welcomed.
Jan 2026 · burnernote.com · its alternatives →
- 8
Thank you for your comments, just some context: - The app is available for iOS, Android, Windows, Mac, Apple Vision Pro, and the Web. - The Web version is implemented as a Progressive Web Application that is very responsive, local first, offline first, can be installed, and is entirely free to use. - Native (hybrid) versions do not require subscription fees and have small one-time payment. - You can store your notes in Git using any Git provider such as GitHub, GitLab, or Bitbucket. However, it has the best built-in integration with GitHub. Self-hosted scenarios like Gitea are also…
2024 · about.noteshub.app · its alternatives →
- 9
Opensidian▲42Opensidian is an open-source, vault-compatible markdown notes app for Linux. Wikilinks, backlinks, graph view and Obsidian community themes. Rust + Tauri v2, no Electron.
10d ago · opensidian.org · its alternatives →
- 10
Uselink▲154Paste Markdown, HTML, or AI-generated drafts. Get a clean public URL with live edits, threaded comments, and version history. No deploy, no sign-in wall.
Jun 2026 · uselink.app · its alternatives →
- 11
I've always thought that extensive reading was best suited for the realm of paper. As a result, I've created a command-line interface (CLI) tailored for my own use and decided to make it open source. I welcome any feedback you may have. [Edit] Sample PDF :: https://drive.google.com/file/d/1n7M1TKOptSsYiibrbvV_Yojx53T...
2024 · github.com · its alternatives →
- 12
Open the ReadKinetic speed reader. Import an EPUB, PDF, or paste text and read with RSVP — entirely in your browser, no signup, works offline.
Jul 2026 · readkinetic.com · its alternatives →
- 13LA
A privacy-first, open-source platform for knowledge management and collaboration.
2020 · logseq.com · its alternatives →
- 14
RSS/Atom feed reader for your desktop.
2025 · rahuldshetty.github.io · its alternatives →
- 15
- 16
Hi! I just made an obsdian alternative in terminal after searching for an Obsidian like TUI and got nothing. The closest I found was Glow, but it's only a markdown reader. I wanted something more powerful for the terminal, so I built one myself.
Dec 2025 · github.com · its alternatives →
- 17
Hi HN. I tested literally dozens of note-taking apps over the years — free, paid, everything. They all sucked except UpNote. Great UX, clean, fast, just works. But your data lives in Google Firebase. Dealbreaker. So I tried Obsidian. Local files, markdown, own your data — great philosophy. But the app itself? Even with everything disabled, as a plain markdown editor it was painful. I actually stopped taking notes entirely. So I built what I wanted: inspired by UpNote's clean design but taken further; less clutter, more polished, with Obsidian's local-first ideology. Your notes are standard…
Aug 2026 · helixnotes.com · its alternatives →
- 18
Hi HN, We have open-sourced Voiden. Most API tools are built like platforms. They are heavy because they optimize for accounts, sync, and abstraction - not for simple, local API work. Voiden treats API tooling as files. It’s an offline-first, Git-native API tool built on Markdown, where specs, tests, and docs live together as executable Markdown in your repo. Git is the source of truth. No cloud. No syncing. No accounts. No telemetry.Just Markdown, Git, hotkeys, and your damn specs. Voiden is extensible via plugins (including gRPC and WSS). Repo:…
Feb 2026 · github.com · its alternatives →
- 19
Go Terminal Feed Reader. Contribute to Lallassu/gorss development by creating an account on GitHub.
2019 · github.com · its alternatives →
- 20TR
2018 · jyotirmoy.net · its alternatives →
- 21
An ESP32 e-reader. Contribute to atomic14/diy-esp32-epub-reader development by creating an account on GitHub.
2021 · github.com · its alternatives →
- 22FA
Freader : A small yet powerful RSS Feed Reader working with Node.js and Angular
2013 · geekuillaume.github.io · its alternatives →
- 23
A Beautiful Open Source RSS & Podcast App Powered by Getstream.io - GetStream/Winds
2016 · github.com · its alternatives →
- 24PW
Hello Hacker News, I've been working on Relentless for a couple months now. I wanted to create a note taking app that lets you write, structure and publish Markdown Notes. I know there are many similar tools out there but I couldn't find something that 1. Works offline. 2. Syncs when online. 3. Provides rich publishing of notes. (Syntax highlighting, Math support) 4. Has GFM support. I think a tool like this needs to exist to make it easier to publish a section of your notes to a website. For me, a lot of creative writing happens in my notes app. There's a lot of essays and short thoughts…
2024 · relentless.so · its alternatives →
Also compare
- ReadHere alternatives
- Epublifier – scrape pages (books, manuals) for offline reading alternatives
- 1paragraph – a browser-based, offline-first ePub reader alternatives
- OpenKnowledge – open source AI-first alternative to Obsidian/Notion alternatives
- Readwise Reader, an all-in-one reading app alternatives
- Flowershow alternatives
Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →