Kernel
Cloud browser infrastructure for AI agents, with millisecond-level cold start, built-in anti-detection, and proxy, making it possible for agents to browse and interact with websites like humans.
Visit Website ↗What is Kernel
Kernel is a 'browser-as-a-service' platform specifically designed for AI agents and web automation. It wraps cloud-based Chromium browsers into APIs and MCP servers, allowing developers to launch a browser in the cloud with a single call, without having to maintain a cluster of headless browsers, handle autoscaling, anti-crawling, and proxy IP management. Built on unikernel technology, Kernel boasts fast cold starts measured in milliseconds, along with live-view and video playback, enabling real-time monitoring and intervention when necessary.
Kernel is a Y Combinator-backed startup that raised $22 million in seed and series A funding led by Accel, with participation from Vercel Ventures and SV Angel, among others, in 2025. It claims to have grown from 0 to over 1,000 customers within seven months. The primary users of Kernel are engineers developing 'self-service' agents, such as those for automatic form filling, crawling dynamic websites, running UI tests, and bypassing anti-bot walls.
Features and Use Cases
Kernel adopts a 'pay-as-you-go' pricing model, charging based on the actual operating time of the browser in seconds, with no additional fees for idle time or proxy usage, and offers a free tier for initial testing. The platform emphasizes its differentiation in performance and cost: officially claimed to have faster cold starts and end-to-end speeds compared to similar services, with significantly lower costs. Additionally, Kernel provides built-in agent identity verification, permission scope, and certificate security management, ensuring agents only act within authorized boundaries. It is suitable for development teams looking to offload web operations to agents without managing browser infrastructure themselves. However, it may not be the best fit for individuals who only occasionally run a couple of crawlers and can suffice with local solutions like Playwright, or for scenarios where data localization regulations restrict session data from being stored in the cloud. As a bottom-layer infrastructure, users still need to write their own agent logic, as Kernel does not handle decision-making.
Key Features
- Millisecond-level cold start cloud browser based on unikernel technology
- Provides API and MCP server for direct integration with agent frameworks
- Built-in anti-detection, residential proxy, and automatic scaling
- Live-view and video playback for real-time monitoring and intervention
- Agent identity verification, permission scope, and certificate security management
Pros
- Fast cold start and cost advantages compared to similar services
- Pay-per-second billing with no charges for idle time or additional proxy fees
- No need to self-manage browser clusters, quick integration into agent workflows
Cons
- Requires users to write their own agent logic, as it's a bottom-layer infrastructure
- Session data stored in the cloud may pose issues for data localization sensitive scenarios
- Individuals with light crawling needs might find local solutions more cost-effective
Use Cases
- Enabling agents to automatically log in to websites, fill forms, and complete processes
- Large-scale crawling of dynamic websites that require login or block bots
- Running end-to-end web UI tests with agents
- Adding 'AI-powered web operation' features to SaaS products
Editor's Note
Editor's note: In 2025, the 'agent goes online' track saw a surge in competitors including Browserbase, Steel, and Hyperbrowser, but Kernel stands out with its unikernel technology achieving millisecond-level cold starts and securing funding led by Accel. Rated 4.4; for Taiwanese developers, this is a relatively niche but practical infrastructure, worth adding to their toolkit for web agent development.
FAQ
How does Kernel differ from running Playwright myself?
The difference lies in not having to manage browser clusters, scaling, anti-detection, and proxies yourself. Kernel packages these into APIs, offering millisecond-level browser launch and live-view, suitable for scalable and stable agent scenarios.
How is the billing calculated?
Billing is based on the actual operating time of the browser in seconds, with no charges for idle time or additional proxy fees, and includes a free tier for initial testing, making it suitable for small-scale verification before scaling up.