Vercel AI Playground - Compare LLMs Side-by-Side

TL;DR

TL;DR: Vercel AI Playground is a free, zero-setup web interface for comparing responses from OpenAI GPT, Anthropic Claude, Google Gemini, Llama, Mistral, and other models side-by-side in a single session.

Source and Accuracy Notes

⚠️ This section is MANDATORY. All links must be verified from actual source, not guessed.

• Project page: play.vercel.ai
• Source repository: None (Vercel Labs proprietary, not open-source)
• License: Proprietary (free to use, no account required)
• HN launch thread: news.ycombinator.com/item?id=35621417

What Is Vercel AI Playground?

Vercel AI Playground is a browser-based tool built by Vercel Labs that lets you run prompts against multiple LLM providers simultaneously and compare their responses in a single view. It launched on Hacker News in early 2025 and quickly reached 249 points.

Instead of opening five separate tabs for GPT, Claude, Gemini, and the rest, you get one split-view interface where every model responds to the same prompt at the same time. This makes it useful for quickly finding which model gives the best answer for a specific task — whether that is code generation, summarization, creative writing, or reasoning.

The interface is built on the Vercel AI SDK, which means it handles provider abstraction under the hood. You do not need an API key to get started; the playground operates in a demo mode with preset model configurations.

Supported Models

The playground includes models from multiple providers:

• OpenAI — GPT-5 series, GPT-4o, GPT-4o-mini, GPT-4-Turbo, GPT-4, GPT-3.5-Turbo
• Anthropic — Claude Opus 4, Claude Sonnet 4, Claude 3.5 Sonnet, Claude 3 Opus, Claude 3 Haiku
• Google — Gemini 2.5 Pro, Gemini 2.5 Flash, Gemini 2.0 Flash, Gemini 1.5 Pro, Gemini 1.5 Flash
• Meta — Llama 4 Scout, Llama 4 Maverick, Llama 3.3 70B, Llama 3.2 Vision, Llama 3.1 models
• Mistral — Mistral Large, Mistral Small, Mistral 7B, Mixtral 8x22B
• DeepSeek — DeepSeek V3, DeepSeek Chat
• ommand — o1, o3, o3-mini, o4-mini (OpenAI reasoning models)
• Google — Gemma 3 27B

Each model shows its provider, context window size, and pricing tier (where known) directly in the model selector.

Setup Workflow

No installation or API key required.

Step 1: Open the playground

Navigate to play.vercel.ai in any modern browser. You land directly on the interface with no sign-in flow.

Step 2: Select your models

Click the model selector to add models to your comparison. You can select up to several models at once. Each selected model gets its own chat tab in the interface.

The selector groups models by provider and shows contextual metadata like context window and pricing tier.

Step 3: Enter your prompt

Type your prompt in the input field at the bottom. All selected models generate responses simultaneously. You watch each response appear in real time as it streams.

Step 4: Compare responses

Scroll horizontally or vertically between model tabs to read full responses. There is no built-in diff view — comparison is visual and manual. The value is seeing how different models interpret the same prompt in context.

Practical Evaluation Checklist

• No account required — open and use immediately
• Streaming responses — watch all models generate simultaneously
• Multi-provider — GPT, Claude, Gemini, Llama, Mistral in one view
• Model metadata visible — context window, pricing tier shown in selector
• No API key needed — demo/preset configuration handles provider calls
• Prompt history — your conversation persists in the current browser session
• Export — copy individual model responses to clipboard

Limitations

The playground does not accept custom API keys, so you are limited to whatever preset model configurations Vercel has enabled. This means you cannot test your own API-credited accounts or use models outside the preset list.

Response quality depends on the demo backend, which may apply rate limiting or default temperature settings. If you need full control over model parameters, you should use the respective provider dashboards or API clients directly.

There is no saved history across sessions, no team collaboration features, and no prompt templating. It is a comparison tool, not a development environment.

FAQ

Q: Is this free to use? A: Yes. Vercel AI Playground is free with no account required. It uses Vercel’s own demo backend.

Q: Do I need API keys? A: No. The playground operates in demo mode with preset model configurations. You cannot plug in your own API keys.

Q: Which providers are supported? A: OpenAI, Anthropic, Google, Meta, Mistral, DeepSeek, and Command models. The full list is visible in the model selector.

Q: Can I adjust model parameters like temperature? A: The playground exposes some parameter controls per model. Not all parameters available via the providers’ APIs are exposed in the UI.

Q: Is this open source? A: The playground itself is not open source. It is a Vercel Labs product built on the open-source Vercel AI SDK.

Q: How does this compare to using ChatGPT or Claude directly? A: The value is simultaneous comparison. Instead of re-running the same prompt across five different services, you see all responses in one place at the same time. For evaluating which model handles a specific task best, this is faster.

Conclusion

Vercel AI Playground is a practical tool for anyone who regularly evaluates LLM outputs — developers comparing model suitability for a task, writers checking tone across models, or researchers doing rapid prompting experiments. It removes the friction of tab-switching and gives you a side-by-side view in one browser window.

The main trade-off is the lack of API key support: you get the preset configurations and nothing more. For ad-hoc comparison needs, that is a fine constraint. For production evaluation pipelines, you would use provider APIs directly.

Try it: play.vercel.ai