What is Fourline used for?

Fourline is a Chrome extension that opens several AI services such as Claude, Gemini and ChatGPT side by side, broadcasts one prompt to all and compares responses in a single workspace. It is a good fit for comparing answers from different AI assistants and keeping several research chats in one window.

How much does Fourline cost?

Fourline is a paid product with no free plan.

Is Fourline open source?

No. Fourline is proprietary (closed-source) software and can't be self-hosted. In the AI Tools category, open-source options include Big-AGI, Zola Chat and Cherry Studio.

What are some alternatives to Fourline?

Fourline competes with Poe and AiZolo.

Fourline: features, pricing and alternatives

About Fourline

Fourline is a browser extension that gathers AI chat services into one control center. Any URL can be opened as a tab and tabs are reordered by dragging, while the extension fetches the title and favicon, with per-tab zoom settings saved automatically and live URL tracking so you keep your place in a long session. Services shown include Claude, Gemini and ChatGPT.

You can work in single-pane mode for focus or split the view to show two or more tabs at once with resizable dividers, and the interface is keyboard-first, with shortcuts to jump to tabs and toggle the sidebar. The key idea is broadcasting a prompt to several assistants at once and comparing the replies side by side instead of switching tabs. The extension is for Chrome and the site has a changelog, company and contact pages. Pricing is not stated in the page text.

Key features

Several AI chat services in one workspace
Broadcast one prompt to multiple models
Side-by-side comparison of responses
Single-pane and split view modes
Tab management with drag and drop
Keyboard shortcuts for tabs and sidebar

Good fit for

Comparing answers from different AI assistants
Keeping several research chats in one window

Tags: chrome-extension; ai-chat; multi-model; comparison; productivity; workspace; research

Fourline: questions and answers

What is Fourline used for?: Fourline is a Chrome extension that opens several AI services such as Claude, Gemini and ChatGPT side by side, broadcasts one prompt to all and compares responses in a single workspace. It is a good fit for comparing answers from different AI assistants and keeping several research chats in one window.
How much does Fourline cost?: Fourline is a paid product with no free plan.
Is Fourline open source?: No. Fourline is proprietary (closed-source) software and can't be self-hosted. In the AI Tools category, open-source options include Big-AGI, Zola Chat and Cherry Studio.
What are some alternatives to Fourline?: Fourline competes with Poe and AiZolo.