Merlin vs Sider
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
AI tool · Freemium
A browser extension giving access to several AI models on any page, for summarising, writing and chat.
AI tool · Freemium
A sidebar AI extension for chatting with pages, PDFs and images using multiple models.
The short answer
Choose Merlin if you need…
- Summarising pages and YouTube videos
- Multi-model chat in the browser
Choose Sider if you need…
- Reading assistance in the browser
- Comparing model answers
Side-by-side
| Merlin | Sider | |
|---|---|---|
| Type | Plugins & extensions · AI browser extensions | Plugins & extensions · AI browser extensions |
| Price | Freemium | Freemium |
| Platforms | Chrome, Web, iOS, Android | Chrome, Web, macOS, Windows, iOS, Android |
| Works with | Chrome, Gmail | Chrome |
| Hands-on tested by us | Not yet | Not yet |
| Last checked | 2026-10-29 | 2026-10-29 |
What each one is
Merlin
A browser extension giving access to several AI models on any page, for summarising, writing and chat. Handy all-in-one sidebar. It can read the pages you visit, so review its permissions.
Sider
A sidebar AI extension for chatting with pages, PDFs and images using multiple models. Capable and popular. Overlaps heavily with similar sidebar extensions.
Best for
Merlin
- Summarising pages and YouTube videos
- Multi-model chat in the browser
Sider
- Reading assistance in the browser
- Comparing model answers
Strengths
Merlin
- Sidebar chat with multiple models
- Page and video summaries
- Writing help in text fields
Sider
- Sidebar chat
- Chat with PDFs and pages
- Image tools
- Translation
Frequently asked questions
What is the difference between Merlin and Sider?
Merlin: A browser extension giving access to several AI models on any page, for summarising, writing and chat. Sider: A sidebar AI extension for chatting with pages, PDFs and images using multiple models. Merlin suits summarising pages and youtube videos, while Sider suits reading assistance in the browser.
Are Merlin and Sider free?
Merlin: Freemium. Sider: Freemium.
What are other alternatives to Merlin and Sider?
Other options people compare them with include MaxAI, HARPA AI, Monica.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.