Your whole AI toolkit, one sidebar away

Sider bolts a ChatGPT-style sidebar onto every webpage. Select text and it summarizes, translates, explains, or rewrites it. Ask questions about the page you're reading. Switch between GPT-4o, Claude, and Gemini without opening a new tab. It's the closest thing to having a research assistant glued to your browser.

Who it's for: Researchers, students, writers, and bilingual professionals who live in the browser and want AI without tab-switching.

Key features

Sidebar Universal sidebar

A persistent AI panel on every page. Highlight any text and act on it — summarize, translate, explain, or improve — without leaving the tab.

Models Multi-model access

Route prompts to GPT-4o, Claude 3.5, Gemini, and Llama. Pick the best model per task from one interface.

Reader AI reader & summarizer

Paste any URL or PDF and Sider produces a structured summary with key points, saving you from reading 20-page docs end to end.

Write Inline AI writer

A writing panel drafts emails, posts, and docs in your tone. Built-in grammar and style suggestions rival standalone editors.

The honest take

✓ What works

Works on any website — no copy-paste between tabs
Access to multiple top models in one place
Strong free tier with daily quota
Excellent translation across 100+ languages
Clean, non-intrusive UI

✗ What doesn't

Premium ($10/mo) required for heavy daily use
Sidebar can feel cramped on small screens
Quality depends on the underlying model you pick
No fully offline mode
Some features overlap with free ChatGPT sidepanel

Verdict

For anyone who spends their day in a browser, Sider is the most convenient AI layer you can add in 2026. The free tier covers casual use; power users will want Premium. It's the fastest way to stop alt-tabbing to ChatGPT.

💡 Transparency: This review contains affiliate links. If you sign up through our link, we may earn a commission at no cost to you. We only recommend tools we use ourselves. Full disclosure.