SiYuan vs Twos
SiYuan
b3log.orgTwos
twosapp.comSide by side
| Figure | SiYuan | Twos |
|---|---|---|
| Price from | $148/mo | $3.33/mo |
| Free plan | Yes | Yes |
| Free trial | Yes | Yes |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| iOS | Yes | Yes |
| Android | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 4 | 4 |
| Spec score · Note-taking apps | 9.1 (#12) | 9.0 (#19) |
| Free plan | Yes | The Free plan includes unlimited things, lists, and to-dos, plus 20 AI chat messages per month. |
| Integrations | Paid options include third-party S3 and WebDAV data sync and backup; users must provide their own storage, and Nutstore is not supported for WebDAV. | Apple Calendar,Google Calendar,Apple Reminders,Email,Text messages,WhatsApp,Slack,Discord,X,Bluesky,Raycast,Readwise,Kindle,Apple Books,Libby,Kobo,Zapier,API,ChatGPT,MCP,Chrome extension |
| Note sharing | Yes | Yes |
| Offline access | Yes | Yes |
| Supported platforms | Windows,macOS,Linux,iOS,Android,web interface,Chrome/Edge extension,API,Docker self-hosting | web,windows,macos,linux,ios,android,chrome_extension,api |
| Privacy | The privacy policy says SiYuan does not collect user personal information or usage data and that data is kept on the user's device under their control. | Twos says it never sells user data and that user content is not used to train AI models. |
| Purpose | SiYuan describes itself as a privacy-first personal knowledge management system supporting Markdown, block-level references, and bidirectional links. | Twos brings notes, to-dos, reminders, events, lists, and links together in one place. |
Plans
SiYuan
- FreeFree
- Subscription$148 a month
- PRO Features$64, paid once
- Subscription$148, paid once
Twos
- FreeFree
- Twos Plus$4.99 a month
- Twos Plus$39.99 a year
- Plus Lifetime$199, paid once
In their own words
SiYuan
SiYuan is a personal knowledge management system for building a linked collection of notes. It supports Markdown, block-level references and bidirectional links, and organizes content into blocks with more than 20 block-level and more than 10 span-level element types. Backlinks can be filtered and searched; relationship graphs are available across a notebook and at block level. Databases support relations, rollups and templates, while flashcards use the FSRS spaced-repetition algorithm. Its AI feature connects to OpenAI for writing continuation, translation, summaries, brainstorming and grammar or spelling corrections. SiYuan supports offline access, and the maker describes multi-device synchronization as incremental and end-to-end encrypted. It is available on Windows, macOS, Linux, iOS, Android and the web, with a Chrome/Edge extension, API and Docker self-hosting. The maker says data stays under the user's control on their device. Free access is free; PRO Features is listed at $64 a month with lifetime-use wording, and Subscription at $148 a month with 8GB cloud storage.
Twos
Twos brings notes, to-dos, reminders, events, lists and links into one place. Items added appear in Today, and unfinished items roll over to tomorrow; users can search saved items or ask Twos about what they have written. It works offline and supports note sharing and real-time collaboration across web, Windows, macOS, Linux, iOS and Android, with a Chrome extension and API. Connections include calendars, reminders, messaging services, social platforms, reading apps, Zapier, ChatGPT and MCP. Authorized ChatGPT and MCP connections can read and write Twos items. Twos describes two-way Apple and Google Calendar sync and Apple Reminders sync on iPhone and iPad, and offers one-time imports from services including Apple Notes, Google Keep, Notion, Evernote, Todoist, Google Tasks and Obsidian. Plus adds templates, archive, week view, customization, multiple accounts, a focus timer and unlimited AI chat. The free plan includes unlimited things, lists and to-dos, plus 20 AI chats per month; Twos Plus costs $4.99 a month and offers a 7-day trial.