Zo vs Readwise

Readwise Reader is one of the most powerful read-it-later apps available. Built by the team behind Readwise (the highlight sync service), it's designed for serious readers who want to retain what they read. It handles articles, PDFs, newsletters, Twitter threads, and even YouTube transcripts.

But like every read-it-later service, your content ultimately lives in someone else's system.

The Pocket Lesson

Mozilla's Pocket operated for 18 years before shutting down on July 8, 2025. Users had until October 8 to export before all data was permanently deleted.

Readwise Reader isn't Pocket. It's a well-funded, actively developed product. But the lesson remains: any service can change or shut down. Your reading archive shouldn't depend on any company's continued operation.

What Readwise Reader Does Well

Readwise Reader is genuinely excellent at what it does:

• Unified content: Articles, PDFs, newsletters, Twitter threads, YouTube transcripts
• Advanced highlighting: Multiple colors, notes, image/table annotations
• Ghostreader AI: Ask questions, define terms, simplify text
• Highlight sync: Seamless connection to the Readwise spaced repetition system
• Integrations: Exports to Notion, Obsidian, Roam Research
• Offline access: Read without internet
• Import from everywhere: Pocket, Instapaper, Kindle highlights

For researchers and serious readers who want to retain information, Reader is excellent.

The Underlying Problem

According to a 2024 Pew Research study, 25% of web pages that existed between 2013 and 2023 are now gone. 66.5% of links over a nine-year period were dead.

Readwise Reader caches content and syncs highlights beautifully. But:

• The content lives on Readwise's servers
• You're saving highlights, not the source material
• If the original disappears and Readwise changes, your archive is at risk
• Your knowledge base depends on continued subscription

We wrote about this: How to save a webpage forever.

How Zo Approaches This Differently

When you save an article on Zo:

1. Zo fetches the page
2. Extracts the content
3. Converts to clean markdown
4. Saves it as a file on your server

The article exists as a file you own that you can sync locally to any device. Not cached in a service - saved as an actual file. You can read it, search it, ask any model about it, and it will still be there in 20 years.

What About Spaced Repetition?

Readwise's killer feature is spaced repetition for your highlights. Review what you've read at optimal intervals to commit it to long-term memory.

Zo has an answer: set up a plain-text flashcard system using hashcards.

Hashcards stores your flashcards as markdown files - the same philosophy as Zo. Your cards are just text files you can edit with any editor, sync with Git, and own forever. It uses FSRS (Free Spaced Repetition Scheduler), the same modern algorithm now available in Anki.

The difference: your flashcards are files you control, not entries in someone else's database. And you can use AI to generate cards from your saved articles.

Different Philosophies

Readwise Reader is built around the idea that you should highlight and review to retain knowledge. It's excellent for that workflow - polished apps, seamless sync, great UX.

Zo is built around the idea that you should own your files and have AI help you work with them. Your articles are markdown files. Your flashcards are markdown files. Everything is portable, version-controllable, and yours forever.

If you want the most polished reading and review experience out of the box, Readwise is hard to beat.

If you want to own your content as files, build your own workflows, and have full control, Zo is the better fit.

Beyond Reading

The bigger difference: Zo is a computer, not just a reading app.

With your saved articles on Zo, you can:

• Ask questions: "Summarize everything I've saved about productivity"
• Build automations: Use scheduled agents to auto-save from newsletters, RSS, specific topics
• Generate flashcards: Ask AI to create spaced repetition cards from your articles
• Create tools: Build custom apps to explore your archive
• Run code: Process, analyze, transform your content

Your archive becomes infrastructure, not just a reading list.

Other Alternatives

Evaluating options after Pocket's shutdown? Here are other read-it-later apps:

• Matter: Modern reading app with AI features ($8/month)
• Instapaper: Classic, clean reading interface
• Raindrop.io: Bookmark manager with reading mode ($33/year)
• Wallabag: Open-source, self-hosted (€11/year hosted)
• Plinky: Apple-focused link saver ($3.99/month)