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FeynmanLM vs Obsidian
Obsidian is the gold standard for owning your notes: free, local Markdown files, endlessly extensible through community plugins. FeynmanLM shares Obsidian's core value — your data lives on your machine, not in someone's cloud — but it solves a different problem. Obsidian is a place to write and link notes. FeynmanLM is a system to track what you consume and verify you understood it. See Why not a note-taking app?
At a glance
| FeynmanLM | Obsidian | |
|---|---|---|
| Price | Free to download; iCloud sync included, no paid sync tier | Free (core app, including commercial use). Sync add-on $4–8/mo; Publish $8/mo |
| AI costs | Pay-as-you-go from a prepaid balance ($5 free to start): any model in Chat at provider API price +15%, or 1¢ per tool call via an AI subscription you already pay for | No built-in AI; community plugins, almost all bring-your-own-key |
| Platforms | Native macOS app (macOS 14+) | macOS, Windows, Linux, iOS, Android |
| Data storage | Local SQLite + files in your private iCloud container, CloudKit sync | Local Markdown files; optional E2E-encrypted paid sync, or DIY iCloud/git sync |
| Source ingestion | Automatic: Safari reading list, Apple Podcasts, PDFs, papers, books, YouTube, X posts | None built in — web clipper for articles; everything else via plugins or manual |
| Podcasts | Follow shows, full episode transcripts | Not supported natively |
| Review method | Feynman-technique dialogue with an AI tutor | None built in; community spaced-repetition plugins, self-graded |
| Model choice | Any MCP-compatible AI, or any API provider in-app | Whatever a plugin supports (BYOK, incl. local models via Ollama) |
| Export | Files in your iCloud Drive; SQLite you can open | Zero lock-in — it's already a folder of .md files |
Pricing verified July 2026 — check obsidian.md/pricing for current numbers.
Pricing: both respect your wallet
Obsidian's core app is genuinely free, and if you sync via iCloud or git, it stays free. Paid Sync is $48–96/yr. AI features require assembling plugins and paying per-token with your own keys.
FeynmanLM is free to download too, and iCloud sync is included — there's no paid sync tier to graduate onto. What you pay for is AI, and only as you use it: a prepaid balance (first $5 free) that draws down either at the provider's own API list price plus 15% when you use the in-app Chat, or at 1¢ per tool call when you drive the app over MCP from a Claude, ChatGPT, Gemini, or Grok subscription you already have. Neither product puts a subscription between you and your own data — the difference is that Obsidian leaves the AI wiring to you, and FeynmanLM meters it for you.
Where Obsidian is better
- It can cost nothing at all, forever, and it runs on every platform — Windows, Linux, Android included. FeynmanLM is also free to install, but it's Mac-only and its AI draws on a paid balance once your free $5 is gone.
- Freeform thinking. Backlinks, graph view, canvas, daily notes — if you want to write, link, and structure your own ideas, Obsidian is built for exactly that. FeynmanLM deliberately isn't a note-taking app.
- Ultimate data ownership. Plain Markdown on disk beats every other storage model for longevity, including FeynmanLM's SQLite-plus-iCloud.
- The plugin ecosystem. Thousands of community plugins; if you can imagine a workflow, someone has built it.
- Local AI. Plugins can run against Ollama models entirely offline — FeynmanLM's AI review requires a cloud provider.
Where FeynmanLM is better
- Capture is automatic. Obsidian ingests nothing by itself — no articles, no podcasts, no papers, no highlights. FeynmanLM auto-discovers sources from your Safari reading list, Apple Podcasts follows, iCloud folders, and reference managers. Many Obsidian users pay $120/yr for Readwise just to pipe content in.
- A learning loop exists out of the box. Obsidian has no review system; spaced-repetition plugins are self-graded flashcards you configure and maintain yourself. FeynmanLM ships a weekly Schedule, Feynman-style AI review sessions, and per-source understanding history — no assembly required.
- The AI reads your actual sources. Through MCP, Claude, ChatGPT, Gemini, or Grok can search your whole library, pull full source text, quiz you on it, and save the review back. Obsidian AI plugins mostly operate on your notes, not on original source material.
- Sources, not just notes about sources. FeynmanLM tracks the article, the paper PDF, the episode transcript itself — with a built-in Reader and Read Aloud — so review is grounded in what the author wrote, not what you managed to write down.
- Zero blank-canvas problem. Obsidian's flexibility is also its tax: you design and maintain your own system. FeynmanLM has one opinionated loop: track, schedule, read or listen, explain it back.
Which should you choose?
Choose Obsidian if your center of gravity is writing and linking your own notes, you need Windows/Linux/Android, or you enjoy building a personal system from plugins.
Choose FeynmanLM if you're on a Mac and your problem isn't note storage — it's that you read, watch, and listen to a flood of material and retain too little of it.
Many people run both: Obsidian for thinking and writing, FeynmanLM for tracking sources and verifying understanding. Both keep your data local, so neither locks the other out.