Arco Chat

Arco is a native macOS app designed for anyone who wants to get the most reliable answer from AI—not just the fastest. Instead of choosing one model and hoping for the best, Arco lets you send a single prompt to dozens of models at once and compare their replies side-by-side. You get a full picture of where models agree, where they differ, and which answer you should trust.

Key Features

Broadcast to all models — Type your question once and send it simultaneously to every model you’ve selected. No copying, no pasting, no hopping between chat sites. All responses appear in your workspace instantly.

AI-powered Summarize — When you have multiple responses, click Summarize to send them to a “judge” model of your choice. You get a structured breakdown of key differences, the best answer, and a recommendation—so you can decide fast.

Fully private — Every conversation stays on your Mac. Data is stored locally and never uploaded to any server. You use your own OpenRouter API key, so Arco never sees your tokens or your queries.

400+ models under one key — Access everything from GPT-4o, Claude, and Gemini to dozens of open-source alternatives through a single OpenRouter API key. No separate accounts or payments for each provider.

Flexible layouts — Arrange model responses in 1, 2, 3, or 4-column grids(upto 6). Hide or resize panes to focus on what matters. Your workspace, your way.

Pay only for what you use — No monthly subscription. You pay OpenRouter’s per-token rates directly. Arco itself offers a free tier (up to 3 saved conversations) and a $49 one-time perpetual license for unlimited use.

Who Is It For?

• Developers — Debug code and compare architecture advice from multiple models to find the most robust solution.

• Writers — Generate multiple drafts, compare tone and style, and pick the version that fits your voice.

• Researchers — Cross-check summaries, surface different perspectives, and decide which interpretation has the strongest reasoning.

• Business teams — Draft reports, generate exec summaries, and pressure-test strategy ideas so you present the version you can defend.

Why Arco Stands Out

Most AI chat apps lock you into a single model. Arco turns model diversity into a strength. Instead of guessing which model is best for a task, you ask them all—and use AI itself to surface the best answer. Privacy is baked in: everything runs locally. And with a one-time purchase model, there’s no recurring fee. If you rely on AI for critical decisions, research, or creative work, Arco gives you the confidence that comes from seeing every option before you choose.