InstaBox: Free Cloud Sandboxes for AI Agents — Honest Notes After a Week of Testing

InstaBox, a cloud sandbox service created by InsForge, is specifically designed for AI agents. Instead of running agent browser/automation work on your own machine, you create cloud machines and let the agents work there. Currently, it operates under an invite-only beta program. After a week of testing the free plan, I have compiled an honest account of what the service offers and its limitations.

Under the free plan, users have access to up to five machines. Each machine runs the agent-browser template featuring a 4-vCPU, 8 GiB RAM, and 20 GiB disk configuration. These files reside on a persistent volume, which means they survive system pauses, shutdowns, and reboots, with deletion of the machine being the only way to lose the data. The free plan operates entirely without any billing in my account, and the team describes it as a generous beta, not a lifetime promise.

I utilized InstaBox for two primary purposes: creating a home base for browser automation that needs to remain logged in and reachable, and conducting network experiments on a throwaway-but-persistent Linux box. The Debian 13 operating system included systemd and sudo functionalities that worked seamlessly. Despite these benefits, the service lacks several features that would make it a VPS replacement.

For instance, machines automatically pause after approximately 30 minutes of idleness, and a continuous run cannot exceed eight hours. Essentially, InstaBox functions as a workbench for AI-agent experimentation, not a 24/7 server.

Additionally, InstaBox does not provide a public inbound IPv4 for your own use. Inbound access is limited to their HTTPS gateway links or SSH gateway. All machines share a single NAT egress IP, which is a US AWS address with a clean reputation but is nonetheless a datacenter IP. Based on my experience, InstaBox stands out as a free workbench for AI-agent experiments.

I highly recommend signing up for the invite list at instabox.sh if you are developing agents that require a browser and a persistent Linux box. However, please refrain from relying on this beta free tier for production hosting purposes.