Arco
Arco is a macOS app that lets you compare 400+ AI models side by side. Bring your own OpenRouter key, choose from models by OpenAI, Anthropic, Google, Meta, and more, and see which one gives the best answer for your specific task. Every conversation stays private on your device.
What is Arco?
Arco is a macOS app that lets you compare 400+ AI models side by side. Bring your own OpenRouter API key and pick from models by OpenAI, Anthropic, Google, Meta, and more to find which one gives the best answer for your specific task. All conversations stay private on your device.
Arco Core Features
400+ model library
Compare outputs from OpenAI, Anthropic, Google, Meta, Mistral, and hundreds more models in one interface.
Side-by-side comparison
Ask one question and see responses from multiple models displayed simultaneously for easy comparison.
Bring your own key
Use your own OpenRouter API key so you control costs and model access without additional subscriptions.
Privacy-first design
All AI conversations process on your device and remain private — no data sent to Arco servers.
macOS native app
Optimized for Mac with native performance, keyboard shortcuts, and seamless system integration.
Flexible model selection
Choose specific models or compare across providers to find the best fit for each task.
Prompt refinement tools
Iterate on prompts and instantly compare how different models interpret the same input.
Cost control
Monitor API usage and costs directly in the app since you use your own OpenRouter key.
Who is Arco for?
Arco is designed for AI developers, prompt engineers, researchers, students, content creators, and anyone who wants to compare outputs from multiple AI models side by side to find the best answer for their specific use case.
Arco Use Cases
Compare AI model outputs side by side to determine which model performs best for your specific task or use case.
Evaluate prompt effectiveness across multiple models to refine and optimize your prompting strategy.
Research and benchmark different AI models for academic studies, blog posts, or technical evaluations.
Select the most cost-effective model for production applications by comparing output quality across price points.
Demonstrate model behavior differences to clients, teams, or students using real-time side-by-side comparisons.
Stay up to date with new model releases by testing them against your existing prompts immediately.
Arco Pros and Cons
Pros
- Side-by-side comparison of 400+ models is a unique and practical workflow not available in most AI chat apps.
- Privacy-first design with local processing ensures conversations stay on your device.
- Using your own API key means no recurring subscription for basic usage — only pay for what you use.
- Covers models from every major provider, making it a universal comparison tool.
- Native macOS app provides better performance and integration than web-based alternatives.
Cons
- Requires an OpenRouter API key and understanding of API-based AI model usage.
- macOS only — no Windows, Linux, or web version available for non-Mac users.
- Free tier has limited daily queries, requiring the Pro plan for heavy usage.
- Does not include built-in model access; depends entirely on your OpenRouter key and provider availability.
FAQ About Arco
Arco Pricing
Arco offers a Free plan and Pro plan at $49/month or lifetime purchase. Bring your own OpenRouter API key.
Check official pricingFree
Free tier for trying AI model comparisons.
- Basic model comparison
- Limited daily queries
- Standard models
Pro
Pro plan for power users. Lifetime license also available.
- Unlimited queries
- All 400+ models
- Priority support