Best cloud sandboxes in 2026

Cloud sandboxes are isolated compute environments that allow for safe execution of untrusted code, feature testing, and AI agent workloads without compromising production systems. They have become increasingly popular due to the rise of AI coding assistants and autonomous agents, which require the ability to handle numerous concurrent executions. Key considerations when selecting a cloud sandbox include the isolation technology used (such as microVMs or gVisor), session duration, ephemeral versus persistent environments, BYOC (Bring Your Own Cloud) support, platform scope, and cold start latency. In 2026, leading platforms like Northflank, E2B, Modal, Fly.io Sprites, Vercel Sandbox, and Together Code Sandbox offer varying approaches to sandbox infrastructure, with Northflank standing out for its comprehensive platform that integrates databases, APIs, GPU workloads, and CI/CD under a single control plane. Northflank also provides robust microVM-based isolation and self-serve BYOC across multiple cloud providers and on-premises, making it a strong choice for teams needing a full workload runtime with stringent security requirements.