# Capacities vs Sider

Capacities records 339,396 monthly visits with +5.7% month-over-month growth and Freemium, Paid pricing. Sider records 2,644,740 monthly visits with -10.6% growth and Freemium pricing.

| Metric | [Capacities](https://openaitools.app/tool/capacities) | [Sider](https://openaitools.app/tool/sider) |
| :--- | :--- | :--- |
| Website URL | https://capacities.io | https://sider.ai |
| Categories | AI Note Taker, AI Assistant, AI Knowledge Management | AI Assistant, AI Chatbot, AI Writing Assistants, AI Reader |
| Pricing Model | Freemium, Paid | Freemium |
| Monthly Visits | 339,396 | 2,644,740 |
| MoM Growth Rate | +5.7% | -10.6% |
| Primary Market | United States | United States |
| Direct Visits | 249,603 | 1,699,535 |
| Review Score | 4.5 | 4.5 |
| Saved Count | 1 | 31 |
| Supported Platforms | Website | Website |

## Capacities

Capacities starts from a simple observation: the way most tools organize information — nested folders and files — does not match how people actually think. The app replaces that hierarchy with objects. A person is an object, a book is an object, a project is an object, and each one has its own structure and properties. Because everything can link to anything, your notes build a network rather than a filing cabinet.

Writing starts in a daily note that acts as an inbox, so there is no pressure to file things immediately. From there you create the object types you actually need and link them as you go. Backlinks show every connection to a note at a glance, and a Related Content feature surfaces places where you wrote about something but never made the link explicit — connections you had already made, found automatically.

Capacities runs on web, macOS, Windows, Linux, iOS and Android, and works offline with synchronisation across devices. The core note-taking product is free, with paid Pro and Believer tiers that add AI features, whiteboards, task management, smart queries, calendar integration, media analysis and version history. The team is small, fully remote and independently funded.

**Pricing & Plans:** Freemium. Capacities Basic is free forever with unlimited spaces, objects and blocks. Capacities Pro is $9.99/month and adds AI features, whiteboards, tasks, smart queries and calendar integration; Capacities Believer starts at $12.49/month and adds beta access to new features. A Plus AI add-on increases the monthly AI budget. Yearly billing is discounted.

- **Everything is an object:** Model people, books, projects and meetings as typed objects with their own properties, instead of forcing them into folders.
- **Backlinks and related content:** See every link to a note at a glance, and let Capacities surface unlinked mentions where you already wrote about the same thing.
- **Daily notes as an inbox:** Capture thoughts without deciding where they belong first, then link and refine them later.
- **AI assistant and media analysis:** On paid plans, an AI assistant works alongside your notes, and image, PDF and weblink analysis turns outside material into usable content.
- **Works across all your devices:** Native apps for web, Mac, Windows, Linux, iOS and Android with synchronisation and offline support.

**Strengths:** Object-based model removes the friction of constant filing decisions; Related Content surfaces connections you never explicitly linked; Free tier is genuinely usable, with full import and export; Native apps on all major platforms, including Linux

**Limitations:** Some of the most useful features — AI, tasks, calendar — sit behind the Pro subscription; Not a Markdown-first, plugin-extensible tool, which limits fine-grained customization; AI usage is budget-based, so heavy AI users need the Plus add-on

[Profile (Markdown)](https://openaitools.app/tool/capacities.md)

## Sider

Sider's premise is that you should not have to leave the page you are reading to use an AI assistant. Its sidebar overlays the browser, detects the content in view, and responds with chat, summaries, translations or explanations using frontier models from multiple providers. The result is a lightweight research and reading workflow: highlight a paragraph, ask for a simpler explanation, translate a PDF and keep the original in sight.

Recent versions push Sider beyond chat. Sider Hand is a browser agent that works across real websites and uses your logged-in sessions to carry out multi-step jobs such as comparing prices while shopping, filling forms, doing cross-site research or triaging a Gmail inbox. Sider Code goes the other way, letting you instruct changes to a website's appearance or behaviour in plain language and preserving the customisation for next time. A Create module generates images, videos, slides and documents from the same panel.

Pricing moves from a limited free tier to credit-based paid plans aimed at heavier users. Lower plans suit occasional chat, summarisation and translation, while higher tiers add a dedicated cloud computer that keeps the browser agent running around the clock and a larger monthly credit allowance. Sider ships as browser extensions for Chrome and Edge plus desktop and mobile apps for macOS, Windows, iOS and Android, and is used by a very large installed base.

**Pricing & Plans:** Freemium. Free tier available with limited credits; paid plans advertised at roughly US$10/month for occasional use up to around US$100/month at the top tier, with higher credit allowances and a dedicated cloud computer on the upper plans.

- **AI sidebar on any page:** A persistent panel that reads the page you are on and answers follow-ups with GPT, Claude or Gemini without copying content into another tab.
- **Summarise and chat with documents:** Summarise long articles, PDFs and YouTube videos, extract key points, and ask detailed questions about the source material.
- **Translation and read-aloud:** Translate webpages, PDFs and images, compare bilingual output side by side, and have content read aloud for review on the move.
- **Sider Hand browser agent:** Delegate multi-step tasks across real websites — price comparison, form filling, research and inbox triage — using your existing logged-in sessions.
- **Sider Code page customisation:** Describe a change in plain words and have Sider restyle or simplify any website, remembering the modification for future visits.

**Strengths:** Works inside the browser you already use, with no context switching; Access to multiple frontier models from one subscription; Strong reading toolkit: PDF chat, YouTube summaries, translation and read-aloud; Increasingly capable agent features for multi-step browser tasks

**Limitations:** Useful credits run out quickly on the free and lower tiers; Model availability and quota rules change over time, so expectations must be checked per plan; Some agent and code features depend on a cloud machine and heavier plans

[Profile (Markdown)](https://openaitools.app/tool/sider.md)

## Frequently Asked Questions

### How do Capacities and Sider compare in monthly traffic?

Capacities has 339,396 monthly visits, while Sider has 2,644,740. Traffic estimates describe audience size, not product quality.

### How do their growth rates compare?

Capacities has a month-over-month growth rate of +5.7%; Sider has -10.6%.

### How does pricing compare?

Capacities: Freemium, Paid. Freemium. Capacities Basic is free forever with unlimited spaces, objects and blocks. Capacities Pro is $9.99/month and adds AI features, whiteboards, tasks, smart queries and calendar integration; Capacities Believer starts at $12.49/month and adds beta access to new features. A Plus AI add-on increases the monthly AI budget. Yearly billing is discounted. Sider: Freemium. Freemium. Free tier available with limited credits; paid plans advertised at roughly US$10/month for occasional use up to around US$100/month at the top tier, with higher credit allowances and a dedicated cloud computer on the upper plans.

## Alternatives

| # | Tool Name | Monthly Visits | MoM Growth Rate | Pricing Model | Summary | Profile (Markdown) |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| 1 | [ChatGPT](https://openaitools.app/tool/chatgpt-4) | 6,048,022,723 | +2.2% | Freemium | OpenAI's flagship multimodal assistant powered by GPT-6 and GPT-5.6 for reasoning, coding, and deep research. | [.md](https://openaitools.app/tool/chatgpt-4.md) |
| 2 | [Claude](https://openaitools.app/tool/claude-2) | 1,253,439,413 | +23.8% | Freemium | Anthropic's frontier AI workspace powered by Claude 5.5 for agentic coding, analysis, and nuanced writing. | [.md](https://openaitools.app/tool/claude-2.md) |
| 3 | [Monica](https://openaitools.app/tool/monica-ai) | 4,512,775 | -11.3% | Freemium | Offers a very similar browser sidebar experience with multiple AI models, but features slightly different pricing and workspace tools. | [.md](https://openaitools.app/tool/monica-ai.md) |
| 4 | [Merlin AI](https://openaitools.app/tool/merlin-ai) | 1,382,634 | +13.1% | Freemium | Provides robust browser-based summarization and prompt assistance, but lacks some of Sider's deeply integrated multi-model chat UI features. | [.md](https://openaitools.app/tool/merlin-ai.md) |
| 5 | [Craft](https://openaitools.app/tool/craft-do) | 703,417 | +8.9% | Freemium | Delivers a cleaner document editing experience with beautiful typography, but lacks network graph views and typed object modeling. | [.md](https://openaitools.app/tool/craft-do.md) |
| 6 | [HARPA AI](https://openaitools.app/tool/harpa-ai) | 537,461 | +99.3% | Freemium | Excels at advanced web automation and data extraction alongside chat, but has a steeper learning curve than Sider. | [.md](https://openaitools.app/tool/harpa-ai.md) |
| 7 | [Noteey](https://openaitools.app/tool/noteey) | 230,694 | -1.6% | Freemium | Offline visual note-taking on an infinite canvas | [.md](https://openaitools.app/tool/noteey.md) |
| 8 | [Glarity](https://openaitools.app/tool/glarity-summarize-google-and-youtube) | 188,823 | -49.6% | Freemium | Summarize YouTube, Google, and any page with AI — free in your browser | [.md](https://openaitools.app/tool/glarity-summarize-google-and-youtube.md) |
| 9 | [Saner.AI](https://openaitools.app/tool/saner-ai-beta-version) | 184,423 | -0.6% | Freemium | ADHD-friendly AI assistant for notes, email and tasks | [.md](https://openaitools.app/tool/saner-ai-beta-version.md) |
| 10 | [Heptabase](https://openaitools.app/tool/heptabase) | 179,905 | -5.8% | Free Trial, Paid | Offers superior visual whiteboarding and spatial structuring for complex research, but lacks Capacities' typed object database system. | [.md](https://openaitools.app/tool/heptabase.md) |

---
Source: https://openaitools.app/compare/capacities-vs-sider

More Markdown: [Categories](https://openaitools.app/categories.md) · [Traffic rankings](https://openaitools.app/rankings.md) · [llms.txt](https://openaitools.app/llms.txt)