Sider

The web is full of long articles, foreign-language pages, and confusing docs — and switching to a separate AI tab breaks your flow. Sider fixes that with an AI sidebar that lives in your browser: highlight any text and summarize, translate, explain, or rewrite it instantly, with 30+ models behind it. This guide covers what Sider is, how it works, and whether it’s worth adding to your browser.

For more AI productivity tools, see our best AI tools in 2026 roundup and the AI Tools directory.

What is Sider?

Sider is an AI-powered browser extension that adds a smart sidebar to your browser, giving you instant access to 30+ AI models wherever you browse. It launched in 2022 and quickly became one of the most popular AI extensions on the Chrome Web Store.

Instead of opening a separate AI chat tab, Sider works in context: you’re reading a page, highlight text, and the AI responds right beside it. Its core tools include:

• Summarize — long articles, videos, and PDFs
• Translate — any highlighted text, with model choices
• Explain — complex passages in simple words
• Rewrite — improve tone, clarity, or length
• Ask anything — a full chatbot in the sidebar

It aggregates models from ChatGPT, Claude, Gemini, DeepSeek, and more, so you get variety without juggling multiple apps.

How Sider works

The workflow is built around your existing browsing:

1. Install the extension and pin the sidebar.
2. Highlight any text on any web page.
3. Choose an action — summarize, translate, explain, rewrite.
4. Sider responds instantly in the sidebar, right beside the text.
5. Or open the chat — ask follow-ups without leaving the page.

Because it lives in the browser, Sider removes the friction of copying text, opening ChatGPT, pasting, and switching back. Highlight → command → done.

Key features of Sider

Instant text actions

Summarize, translate, explain, and rewrite any highlighted text without leaving the page — the core workflow that saves the most time.

30+ models in one place

Access ChatGPT, Claude, Gemini, DeepSeek, and more from a single sidebar, with the ability to pick models or compare answers.

Whole-page understanding

Sider summarizes entire pages, PDFs, and YouTube videos, not just selections — perfect for research and digesting long content.

Sidebar chat

A full AI chat in the sidebar that keeps your browsing context, so you can ask questions about what you’re viewing without switching tabs.

Multilingual support

Strong translation and cross-language assistance, useful for reading foreign-language sites and working across languages.

Sider vs. Monica vs. other AI extensions

	Sider	Monica	ChatHub
AI sidebar on any page	✅ Yes	✅ Yes	Chat only
Models available	30+	GPT/Claude/Gemini	20+ (compare)
Free tier	✅ Daily quota	✅ 40 queries/day	✅ Yes
Best for	Summarize/translate on the fly	Writing assistance	Comparing models

Sider is the strongest all-rounder for reading and research tasks. Monica excels at writing and editing assistance. ChatHub is specialized for side-by-side model comparison. Each fills a slightly different role in a productivity stack.

Who is Sider for?

• Students and researchers digesting lots of reading.
• Professionals dealing with long reports and documents.
• Multilingual users translating content constantly.
• Content consumers who want AI in their browsing flow.

It’s not for Firefox/Safari users (Chrome/Edge only), or for heavy daily use on the free tier (quotas apply). For deep one-on-one conversations, a full chatbot like DeepSeek or Qwen Chat is a better fit.

How to get started with Sider

1. Install Sider from the Chrome Web Store.
2. Pin the sidebar icon for one-click access.
3. Highlight text on any page and try summarize or translate.
4. Configure your favorite model in settings.
5. Try page summarization — great for long articles and videos.
6. Upgrade only if your daily quota feels limiting.

Start with the free tier and the summarize command — once you feel the flow, the rest of the features follow naturally.

The bottom line

Sider puts AI right where you browse, eliminating the tab-switching that makes AI helpers feel clunky. With 30+ models, instant text actions, and page-level understanding, it’s one of the most practical AI extensions for reading and research. If you live in a browser, it earns its place fast.

For a complete free AI stack, pair Sider with ChatHub for model comparison and NotebookLM for deep research.

Official resource: Sider.