Claude Sonnet 5 Guide.

Ranked guide · 5 picks

Best Claude Chat Apps & AI Workspaces for Sonnet 5

Want Claude Sonnet 5 at your fingertips everywhere — in your browser, on your desktop, or across your whole workspace? These AI assistants and workspaces put Claude (and other top models) one click away.

01

AI assistant everywhere you browse

Merlin AITop pick

Merlin is a browser assistant that brings Claude — plus 20+ other models — to any website. Chat, summarize, write and research from a sidebar wherever you work.

Claude Includes Claude 4.5 / Sonnet in the model list.

Strengths

  • Claude Sonnet + many models
  • Works on any website
  • 30% recurring affiliate

Trade-offs

  • Browser-extension centric
  • Model access varies by plan
Free; Pro from $19/mo Try Merlin
02

All-in-one AI assistant

Monica

Monica is an all-in-one AI assistant for chat, writing and search — with dedicated Claude Sonnet models alongside other top LLMs, on the web and desktop.

Claude Dedicated Claude Sonnet models in the picker.

Strengths

  • Claude Sonnet built in
  • Web + desktop apps
  • 25% recurring affiliate

Trade-offs

  • Feature-dense
  • Best on paid plans
Free; Pro from $8.30/mo Try Monica
03

Chat with Claude + GPT in a sidebar

Sider

Sider is a browser sidebar to chat with Claude, GPT and Gemini side-by-side — read PDFs, summarize pages, and write anywhere on the web.

Claude Claude Sonnet 4.5/4.6 available in the model picker.

Strengths

  • Claude Sonnet selectable
  • Great PDF & webpage tools
  • High recurring affiliate %

Trade-offs

  • Extension-based
  • Credits by plan
Free; Pro from $10/mo Try Sider
04

AI workspace & agents

Taskade

Taskade is an all-in-one AI workspace — build agents, docs and projects — with Claude Sonnet available in the agent model selector.

Claude Claude Sonnet in the agent model selector.

Strengths

  • Claude Sonnet agents
  • All-in-one workspace
  • Lifetime recurring affiliate

Trade-offs

  • Broad feature set to learn
  • AI limits on lower tiers
Free; paid from $8/mo Try Taskade
05

One-click AI on any page

MaxAI.me

MaxAI.me brings Claude, GPT and Gemini to any webpage — rewrite, summarize, translate and chat from a single shortcut, wherever you are.

Claude Ask AI with Claude Sonnet models.

Strengths

  • Claude selectable
  • Works on any page
  • 25% recurring affiliate

Trade-offs

  • Extension-based
  • Best on Pro
Free; Pro from $8.25/mo Try MaxAI

Frequently asked questions

Why use a third-party Claude app instead of claude.ai?

Two reasons: access to multiple models (Claude, GPT, Gemini) under one subscription, and integration where you work — browser sidebars, desktop apps, workspace tools. If you only want Claude, claude.ai itself is the better value.

Do these apps include Claude Sonnet 5?

The major ones (Merlin, Monica, Sider) typically add new Claude models shortly after release, usually metered by a credit system. Check each app's model list — 'Claude' on the pricing page doesn't always mean the newest Sonnet.

Are AI assistant browser extensions safe?

The established ones are legitimate businesses, but any browser extension that reads pages deserves scrutiny. Read the privacy policy, prefer apps with clear data-retention terms, and avoid pasting sensitive data into any third-party AI tool.