Sider Review (2026): Pricing, Features & Honest Verdict

TLDR

Sider is an AI browser sidebar extension with 10M+ users that integrates ChatGPT, Claude, Gemini, and DeepSeek into a single interface. We found its Deep Research agent and Wisebase knowledge base genuinely useful for anyone who researches online, though the credit system can be confusing and heavy usage gets expensive fast. Best for: researchers, writers, and knowledge workers. Price: From $8.30/mo. Free plan: Yes (30 daily credits). Rating: 8/10.

What is Sider?

Sider is an AI-powered browser sidebar that gives you access to all major AI models from any webpage without switching tabs. Originally launched in 2019 as a simple ChatGPT sidebar extension, it has grown into a comprehensive AI research and productivity platform serving over 10 million active users with a 4.9-star rating. The 5.0 release in March 2025 introduced two flagship features: a Deep Research agent that scans 100+ sources and generates cited reports, and Wisebase, a personal AI knowledge base where all findings are automatically saved.

We found Sider as a Product of the Week winner on Product Hunt (March 2025, 811 upvotes). The company behind it is Vidline Inc., based in Boston, originally founded in Tokyo by Koichiro Sumi. It started as an automated code review tool for GitHub before pivoting to the AI assistant product. The company reached $7.2M in revenue in 2024 and claims to be one of the only bootstrapped startups featured on OpenAI’s platform. That is impressive scale without venture funding.

What Are Sider’s Key Features?

Deep Research Agent

The headline feature of Sider 5.0. It mimics the human research process by auto-scanning 100+ web pages, cross-validating findings across multiple sources to reduce hallucinations, reflecting on discoveries, and generating expert-level interactive reports with citations. Each report includes auto-generated notes, source links, and highlighted key information. Users can ask follow-up questions within the report. It supports cross-language research, breaking language barriers for multilingual queries. One free use is included, with expanded access on paid plans.

Multi-Model Group Chat

Sider provides access to GPT-5, Claude Opus 4, Gemini 2.5 Pro, DeepSeek-R1, Grok 4, and many more models in a single interface. The unique Group Chat feature lets you query multiple models simultaneously and compare their responses side by side. Sider Fusion automatically selects the best model for each task based on cost, style, and factuality tradeoffs. No other browser extension offers this level of multi-model access and comparison.

Wisebase Knowledge Base

Wisebase is a personal, evolving knowledge base where Deep Research reports, web highlights, notes, and uploaded documents are automatically saved. You can chat with your saved knowledge for deeper understanding, convert notes into content drafts, outlines, or articles, and share files with colleagues via a single link. It functions as a “second brain” that grows with your research over time.

Always-Available Browser Sidebar

The sidebar works on any webpage for translation across 50+ languages, summarization of articles, PDFs, and YouTube videos, content creation, code explanation, and AI chat. Unlike ChatGPT (website-based), Claude (standalone app), or Perplexity (separate tab), Sider meets you where you already browse. It works on Reddit, Gmail, research articles, and any other site without context-switching. Additional tools include AI Slides, a Web Creator, audio transcription with speaker identification, and image generation.

How Much Does Sider Cost?

Sider starts with a free plan offering 30 Basic Credits per day and limited access to tools. The Basic plan costs $8.30 per month with 3,600 Basic Credits and 100 Advanced Credits monthly. The Pro plan is $16.60 per month with 12,000 Basic Credits and 300 Advanced Credits. The Unlimited plan runs $25 per month with unlimited Basic and Advanced Credits (minimum 1,000 guaranteed). A newer Ultra plan is available for heavy agent-driven workflows with the highest Elite Credit allocation.

The credit system uses three tiers: Basic Credits for lighter models like GPT-4o mini, Advanced Credits for premium models like GPT-5 and Claude Sonnet 4, and Elite Credits for agent features like Deep Research and AI Slides. This tiered approach is flexible but confusing for new users. Claude Sonnet 4.5 and Gemini 3 Pro cost 2 Advanced Credits per task, and Thinking mode variants cost even more. Heavy users can burn through Advanced Credits quickly. Compared to a direct ChatGPT Plus subscription at $20 per month or Perplexity Pro at $20 per month, Sider’s value depends on whether you use the multi-model access enough to justify the complexity.

Who is Sider Best For?

Use Sider if you spend significant time researching, reading, and synthesizing information across the web. It works best for students writing papers, analysts building reports, writers creating content from multiple sources, and knowledge workers who want AI assistance without leaving their browser. The Deep Research agent saves hours of manual research, and Wisebase turns that research into a reusable knowledge asset. If you currently switch between ChatGPT, Claude, and Perplexity depending on the task, Sider consolidates all three.

Skip Sider if you only need one AI model and are happy with ChatGPT or Claude directly. The multi-model complexity adds cognitive overhead without much benefit for simple use cases. Also skip it if you are budget-sensitive and do not need the advanced models. The free tier is restrictive (30 daily credits), and upgrading just for occasional AI questions is not cost-effective when ChatGPT’s free tier is more generous for casual users. Privacy-conscious users should also consider that browser extensions with broad permissions can access sensitive page content.

Best Sider Alternatives

Perplexity AI (free, Pro at $20/mo)

Research-focused AI that always cites sources. Better for pure research tasks where source verification matters. Lacks the browser sidebar integration, multi-model chat, and knowledge base features that Sider offers.

Monica AI (free tier plus paid plans)

The most direct competitor as an all-in-one AI browser assistant. Similar feature set including multi-model access and sidebar integration. Generous free plan. The choice between Monica and Sider often comes down to personal preference in UI and model selection.

ChatGPT Plus ($20/mo)

The most popular general-purpose AI with web browsing, code execution, and image generation. Simpler and more polished for single-model usage. Now offers a browser extension. Cannot compare multiple models simultaneously.

Final Verdict: Is Sider Worth It?

Sider has evolved from a simple ChatGPT sidebar into one of the most comprehensive AI browser tools available. The Deep Research agent genuinely saves hours of manual research by scanning 100+ sources and producing cited, interactive reports. Wisebase turns ephemeral research into a persistent knowledge base. The multi-model Group Chat is a feature no competitor matches, letting you compare answers from GPT-5, Claude, and Gemini in a single conversation. At 10M+ users and $7.2M in revenue, the product has been validated at scale.

The credit system is the main friction point. Three credit tiers (Basic, Advanced, Elite) with different costs per model create a mental overhead that simpler tools avoid. Heavy users of premium models will find Advanced Credits disappearing faster than expected. The sheer number of features can overwhelm new users who just want a quick AI sidebar. But if you do serious research online and want one tool that replaces multiple AI subscriptions, Sider delivers more capability per dollar than any competitor we have tested. The $25/month Unlimited plan is the sweet spot for power users.