Project Mariner vs Stagehand
Two of the most-asked-about agents in the autonomous space. Here's how they actually stack up.
Project Mariner
Google DeepMind's experimental browser agent for completing web tasks
From $20/mo
Read full review →Stagehand
Open-source browser automation framework pairing natural-language actions with deterministic Playwright execution
Free
Read full review →Side-by-side comparison
| Project Mariner | Stagehand | |
|---|---|---|
| Tagline | Google DeepMind's experimental browser agent for completing web tasks | Open-source browser automation framework pairing natural-language actions with deterministic Playwright execution |
| Pricing | From $20/mo | Free |
| Categories | autonomous, browser-agent, research | browser-automation, web-scraping |
| Made by | Google DeepMind | Browserbase |
| Launched | 2024-12 | 2024-08 |
| Platforms | Chrome browser | macOS, Linux, Windows |
| Status | active | active |
Project Mariner highlights
- + Chrome extension that takes over the active browser tab to complete multi-step tasks
- + Gemini 2.0 multimodal brain reads pixels, web elements, text, forms, and images simultaneously
- + Sandboxed execution: agent is limited to the currently active tab and cannot access other tabs or local files
- + Human-in-the-loop confirmation gates for sensitive actions such as purchases or form submissions
- + 83.5% score on the WebVoyager benchmark for end-to-end web task completion
Stagehand highlights
- + Natural-language browser actions with AI model backends
- + Deterministic Playwright fallback for reliable automation
- + TypeScript and Python SDKs
- + Compatible with any LLM provider via configuration
- + Browserbase managed browser hosting integration
Frequently Asked Questions
Which is better, Project Mariner or Stagehand?
Neither is universally better. Project Mariner (From $20/mo) leans into autonomous, while Stagehand (Free) is closer to browser-automation. Pick based on which workflow you actually do every day.
What is the price difference between Project Mariner and Stagehand?
Project Mariner is from $20/mo. Stagehand is free. See the pricing row in the comparison table.
Can I use Project Mariner and Stagehand together?
In most cases, yes. They serve overlapping but distinct needs, so running them side by side is common until you decide which fits your workflow.