Comparison
Obsidian vs Readwise vs Cosminds
All three help you do something with what you read. They are built for different jobs: Obsidian to own your notes, Readwise to collect your highlights, Cosminds to remember what you read. Here is an honest side by side, including where each one wins.
Free to start. No credit card.
| Feature | Obsidian | Readwise | Cosminds |
|---|---|---|---|
| Built for | Notes you own and link | Saving and resurfacing highlights | Remembering what you read |
| Organizes by | Files, folders, and links | The source it came from | The idea, across every source |
| Tests your recall | Only via a spaced-repetition plugin | Daily highlight resurfacing (recognition) | Three-round drill, AI grades what you write from memory |
| Ask your own library | Through a paid AI add-on | Ghostreader, over one document | AI Wiki over everything, with citations, refuses when you have not read it |
| Data ownership | Local Markdown files you fully own | Cloud, export to Notion and Obsidian | Cloud, one-tap export of everything as JSON |
| Where sources come from | Manual, or a plugin per source | Kindle, Instapaper, X, podcasts, email, mature | Upload, paste, YouTube, article link, phone photo of a page |
| Works offline | Yes, fully | Reader caches for offline reading | No, forging is server-side |
| Free tier | Yes, the full app is free for personal use | No, 30-day trial only | Yes, 8 credits a week, AI Wiki included |
| Price | Free core; Sync from $4/mo, Publish from $8/mo | $9.99/mo billed annually (Reader included) | Free, or $10 Pro / $25 Scholar |
Which one is for you
Pick by the job, not the feature list.
Obsidian
You want to own your files, work offline, and build your own system from plugins. It is free, local, and endlessly extensible. It is a notes tool, not a memory tool, so recall is on you to bolt on.
Readwise
You highlight across Kindle, articles, and podcasts and want them in one place, resurfaced daily. Its syncing breadth is unmatched. Resurfacing shows you a highlight; it does not ask you to reproduce it.
Cosminds
You want to actually remember what you read, not just store it. It extracts the claims, organizes them by idea, and drills you until you can write them from memory. It is cloud-based and newer, so you trade local ownership for active recall.
FAQ
Is Cosminds a replacement for Obsidian?
Not exactly, because they do different jobs. Obsidian is where you own and link your notes, offline and free. Cosminds is where you make what you read stick, by extracting the claims and drilling you until you can reproduce them from memory. Some people keep notes in Obsidian and use Cosminds to actually remember the sources.
How is Cosminds different from Readwise?
Readwise collects your highlights from Kindle, articles, and podcasts and resurfaces one each day, which is recognition: you see it again. Cosminds asks you to produce the idea from memory and grades whether you got the meaning, which is recall. Readwise has far broader highlight syncing; Cosminds is built around the retrieval that actually builds memory.
Which should I choose for remembering what I read?
For remembering specifically, Cosminds, because it is the only one of the three built around active recall rather than storage or resurfacing. For owning your files offline, Obsidian. For the widest highlight collection, Readwise. They are not mutually exclusive.