Merlin AI vs Sider

Two fact sheets from our own research, side by side — pricing, platforms, API access and status re-checked by us rather than quoted from the vendors.

The short answer

Free plan: Both have one
Best fit: Merlin AI: People who compare answers across frontier models before trusting one · Sider: Reading and summarizing long articles or PDFs without leaving the page
Platforms: Merlin AI: Web, Chrome extension, iOS, Android · Sider: Web, Chrome extension, Windows, macOS, iOS, Android
Trust score: About even — Merlin AI 86, Sider 88
Status: Both up at our last check — Merlin AI Oct 27, 2026, Sider Oct 14, 2026

From our own records as of each tool's last check. Anything we have not confirmed is left out rather than guessed. How we verify

Merlin AIBrowser sidebar running many chat models on any page

SiderBrowser sidebar that puts GPT, Claude, Gemini, and other models next to any page you're reading.

Side by side

Fact	Merlin AI	Sider
Category	Browser Extensions & Copilots	Browser Extensions & Copilots
Pricing model	Freemium	Freemium
Trust score	86 / 100	88 / 100
Platforms	Web, Chrome extension, iOS, Android	Web, Chrome extension, Windows, macOS, iOS, Android
Company	Foyer Tech Inc.	Sider
Launched	2022	—
Last verified	Oct 27, 2026	Oct 14, 2026

What our research says

Merlin AI

Buy it if you genuinely rotate between GPT, Claude and Gemini and resent paying three subscriptions — the aggregation is the whole value. If you live inside one model, its native app is faster, cheaper and gets features first.

Pros

One subscription reaches a dozen-plus frontier and open models
Extension surfaces the assistant directly on Gmail, YouTube, Google and LinkedIn
Mobile apps sync history, so the browser session continues off desktop
Real free tier for evaluating before paying

Cons

'Unlimited' paid plans are governed by an opaque fair-use credit budget users hit without warning
Extension is desktop-Chromium only; mobile browsers get a reduced web app
Feature parity with each underlying model's own app is never complete
No developer API

Sider

Sider puts a chat panel on top of whatever page you're on, so you can ask about an article or PDF without copying it into a separate tab. The catch is that heavier use beyond the free daily cap needs a paid tier, and pricing quoted across review sites is inconsistent, so the entry price is worth confirming before committing.

Pros

Works as a sidebar on any web page rather than a separate chat tab
Routes one prompt to several models (GPT, Claude, Gemini, DeepSeek, Grok)
Ships native apps for iOS, Android, Windows, and Mac plus browser extensions
Can chat with PDFs and YouTube videos, not just plain text

Cons

Free tier is capped at a small number of daily uses
Independent pricing write-ups disagree on exact plan costs depending on where you check
No public API for developers

Which one fits

Choose Merlin AI if you need

People who compare answers across frontier models before trusting one
Heavy in-browser workflows: summarising videos, articles and inbox threads in place
Users who want one bill instead of separate OpenAI, Anthropic and Google subscriptions

Choose Sider if you need

Reading and summarizing long articles or PDFs without leaving the page
Comparing answers from several models in one panel
People who want one subscription instead of several separate chatbot logins