# Dex by Thirdlayer vs Sider

Dex by Thirdlayer records 9,262 monthly visits with +9.5% month-over-month growth and Freemium pricing. Sider records 2,644,740 monthly visits with -10.6% growth and Freemium pricing.

| Metric | [Dex by Thirdlayer](https://openaitools.app/tool/dex-by-thirdlayer) | [Sider](https://openaitools.app/tool/sider) |
| :--- | :--- | :--- |
| Website URL | https://joindex.com | https://sider.ai |
| Categories | AI Browsers, AI Assistant, AI Task Management | AI Assistant, AI Chatbot, AI Writing Assistants, AI Reader |
| Pricing Model | Freemium | Freemium |
| Monthly Visits | 9,262 | 2,644,740 |
| MoM Growth Rate | +9.5% | -10.6% |
| Primary Market | United States | United States |
| Direct Visits | 5,753 | 1,699,535 |
| Review Score | 4.3 | 4.5 |
| Saved Count | 0 | 31 |
| Supported Platforms | Website | Website |

## Dex by Thirdlayer

Dex is built around the idea that agents fail when they only retrieve facts. Instead of a shallow search layer, Dex assembles two linked memory systems: an Operational Graph that records entities, relationships, timelines and dependencies across your operations, and a Knowledge Manual that holds the judgment layer — priorities, open loops, relationship context, SOPs and operating principles. The manual is explicitly editable and automatically maintained, so you stay in control of what the AI treats as true.

On top of that context, Dex runs autonomous agents that orchestrate across Gmail, Slack, CRM systems and 20+ other tools, triggered by events or schedules. Because it lives in the browser, it can also act directly in the page: navigating tabs, filling forms and completing work where the context already exists. Your operational context is portable too — an SDK and MCP support let you bring it into other agents and workflows.

Dex also improves with use. It learns from your corrections, approvals and repeated patterns. A Dreamer Agent reasons around the clock over new data to spot emerging patterns and keep your knowledge base current, while a Skill Builder Agent proposes custom automations each week based on the workflows you repeat. Typical wins include meeting prep with full history, follow-ups drafted from call notes, task triage that reflects your priorities, and CRM updates without manual data entry. Dex is available on Chrome (with iMessage, Slack and desktop clients listed as coming soon), offers 256-bit encryption, and supports private cloud deployment for teams that need data isolation.

**Pricing & Plans:** Freemium with an onboarding-based entry point. The site invites users to install Dex and then book an onboarding call; the vendor also mentions talking to them about private cloud, which is typically an enterprise conversation. No public price list is published, so check the site for current plan details.

- **Operational Graph:** A living organisational record that organises every message, meeting, deal update and workflow event into entities, relationships, timelines and dependencies.
- **Knowledge Manual:** An editable, automatically maintained layer for priorities, open loops, SOPs and operating principles — the judgment side of your assistant.
- **Autonomous agents:** Agents that orchestrate across Gmail, Slack, CRM and 20+ tools, triggered by events or on a schedule.
- **Browser control:** Dex can navigate tabs, fill forms and complete tasks directly in your browser, cutting context switching.
- **Dreamer and Skill Builder agents:** One reasons 24/7 over new data to keep context current; the other proposes custom automations weekly from your repeated workflows.
- **SDK and MCP access:** Bring your operational context into any other agent, tool or workflow you already use.

**Strengths:** Differentiated memory model that separates factual retrieval from judgment-based reasoning; Browser-first design means it works where your context already lives; Acts as well as answers: agents execute tasks across Gmail, Slack, CRM and more; Context is portable via SDK and MCP rather than locked inside one chat window

**Limitations:** Onboarding is currently invite/call-based rather than fully self-serve; Requires connecting several tools and some ramp-up before the context compounding pays off; No public price list, so budgeting requires contacting the vendor; Some clients (iMessage, Slack, desktop) are still listed as coming soon

[Profile (Markdown)](https://openaitools.app/tool/dex-by-thirdlayer.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 Dex by Thirdlayer and Sider compare in monthly traffic?

Dex by Thirdlayer has 9,262 monthly visits, while Sider has 2,644,740. Traffic estimates describe audience size, not product quality.

### How do their growth rates compare?

Dex by Thirdlayer has a month-over-month growth rate of +9.5%; Sider has -10.6%.

### How does pricing compare?

Dex by Thirdlayer: Freemium. Freemium with an onboarding-based entry point. The site invites users to install Dex and then book an onboarding call; the vendor also mentions talking to them about private cloud, which is typically an enterprise conversation. No public price list is published, so check the site for current plan details. 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 | [Dia Browser](https://openaitools.app/tool/dia-browser) | 1,254,172 | +108.4% | Free | The AI browser that reads between your tabs | [.md](https://openaitools.app/tool/dia-browser.md) |
| 6 | [Tabbit Browser](https://openaitools.app/tool/tabbit-ai) | 670,981 | -30.2% | Freemium | The agentic AI browser that reads your tabs, files, and screenshots as context | [.md](https://openaitools.app/tool/tabbit-ai.md) |
| 7 | [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) |
| 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 | [Kome AI](https://openaitools.app/tool/kome-ai) | 174,910 | -6.5% | Freemium | Integrates bookmark management and content composition into a clean sidebar, but has a more limited feature set than Sider. | [.md](https://openaitools.app/tool/kome-ai.md) |
| 10 | [Voilà — AI Assistant, Chat and Writer](https://openaitools.app/tool/voil-chatgpt-browser-assistant) | 152,170 | -4.8% | Freemium | Delivers streamlined inline writing and webpage summarization via a browser extension, but with fewer custom sidebar tools. | [.md](https://openaitools.app/tool/voil-chatgpt-browser-assistant.md) |

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Source: https://openaitools.app/compare/dex-by-thirdlayer-vs-sider

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