{"slug":"best-code-sandbox-for-ai-agents","title":"Best code execution sandbox for AI agents","question":"What are the best sandboxed code execution platforms for AI agents in 2026?","verdict":"As of 2026-07-15, ChatGPT, Claude, Gemini and Grok collectively rank E2B #1 for code execution sandbox for ai agents on ModelsAgree — a unanimous pick. The models' case: Best all-around, purpose-built agent sandbox: secure microVM isolation, fast startup, excellent Python/TypeScript SDKs, reusable templates, filesystem and process APIs. The models' main caveat: Meaningful production concurrency and 24-hour sessions require a $150/month Pro plan, making sustained workloads expensive. The strongest alternative is Modal — Sandboxes as a primitive inside a broader serverless platform — gVisor isolation, sub-second starts, easy GPU attachment, image building in code, and. Source: https://modelsagree.com/best/best-code-sandbox-for-ai-agents (modelsagree.com, CC BY 4.0).","category":"Agents","url":"https://modelsagree.com/best/best-code-sandbox-for-ai-agents","updated":"2026-07-15","models":["ChatGPT","Claude","Gemini","Grok"],"consensus":"All 4 models rank E2B the top pick","disagreement":null,"combined":[{"rank":1,"product":"E2B","domain":"e2b.dev","score":20,"appearances":4,"modelRanks":{"ChatGPT":1,"Claude":1,"Gemini":1,"Grok":1},"reason":"Best all-around, purpose-built agent sandbox: secure microVM isolation, fast startup, excellent Python/TypeScript SDKs, reusable templates, filesystem and process APIs, desktop environments, and the deepest agent-framework ecosystem."},{"rank":2,"product":"Modal","domain":"modal.com","score":13,"appearances":4,"modelRanks":{"ChatGPT":3,"Claude":2,"Gemini":3,"Grok":3},"reason":"Sandboxes as a primitive inside a broader serverless platform — gVisor isolation, sub-second starts, easy GPU attachment, image building in code, and massive burst scale, so agent code execution and the rest of your AI infra (batch jobs, inference, training) live in one system with excellent Python DX."},{"rank":3,"product":"Daytona","domain":"daytona.io","score":10,"appearances":4,"modelRanks":{"ChatGPT":2,"Claude":3,"Gemini":4,"Grok":5},"reason":"Near-tie with E2B on practitioner value; exceptionally complete lifecycle management—snapshots, forks, pause/resume, recovery, resizing—and support for containers, Linux VMs, Windows, and GPUs with straightforward usage pricing."},{"rank":4,"product":"Blaxel","domain":"blaxel.ai","score":4,"appearances":2,"modelRanks":{"ChatGPT":4,"Grok":4},"reason":"Best persistent-agent design: isolated VMs resume from standby in under 25 ms, scale to zero while retaining memory and filesystem state, and provide MCP, previews, volumes, firewalling, and managed lifecycle APIs."},{"rank":5,"product":"Northflank","domain":"northflank.com","score":4,"appearances":1,"modelRanks":{"Grok":2},"reason":"Production-grade microVM options (Firecracker/Kata/gVisor) with unlimited sessions, BYOC/self-hosting, full platform integration (DBs, GPUs, deployments), and strong compliance/isolation for scaling agent workflows beyond prototypes; serves practitioners needing reliable infra."},{"rank":6,"product":"Upstash Box","domain":"upstash.com","score":4,"appearances":1,"modelRanks":{"Gemini":2},"reason":"Replaces complex workspace state management by bringing serverless developer mechanics to agent sandboxes, offering durable block storage and auto-scaling to zero when idle with instant wake-ups."},{"rank":7,"product":"Cloudflare Sandbox SDK","domain":"cloudflare.com","score":2,"appearances":1,"modelRanks":{"Claude":4},"reason":"Sandboxed code execution co-located with the edge platform many agents already run on — per-sandbox container isolation orchestrated by Durable Objects, preview URLs, a code-interpreter API, and zero extra vendor if you're already on Workers; pricing and global placement are hard to beat for lightweight interpreter workloads."},{"rank":8,"product":"Azure Container Apps dynamic sessions","domain":"microsoft.com","score":1,"appearances":1,"modelRanks":{"Claude":5},"reason":"The enterprise pick — Hyper-V-isolated session pools with sub-second allocation from warm pools, per-second billing, native LangChain/Semantic Kernel integrations, and the compliance/network-integration story (VNet, Entra) that regulated shops require before letting LLM-generated code run anywhere. Rank assumes the practitioner values governance over DX; on pure ergonomics it trails the top three."},{"rank":9,"product":"CodeSandbox SDK","domain":"codesandbox.io","score":1,"appearances":1,"modelRanks":{"Gemini":5},"reason":"Optimized for AI coding agents that need to build, test, and run full-stack web applications, featuring built-in browser previews, live filesystem watching, and instant snapshotting."},{"rank":10,"product":"Runloop","domain":"runloop.ai","score":1,"appearances":1,"modelRanks":{"ChatGPT":5},"reason":"Excellent for software-engineering agents and evaluation fleets, with microVM isolation, blueprints, snapshot branching, suspend/resume, browser support, credential brokering, egress policies, benchmarks, and VPC deployment."}],"perModel":{"ChatGPT":[{"rank":1,"product":"E2B","reason":"Best all-around, purpose-built agent sandbox: secure microVM isolation, fast startup, excellent Python/TypeScript SDKs, reusable templates, filesystem and process APIs, desktop environments, and the deepest agent-framework ecosystem.","fix":"Meaningful production concurrency and 24-hour sessions require a $150/month Pro plan, making sustained workloads expensive."},{"rank":2,"product":"Daytona","reason":"Near-tie with E2B on practitioner value; exceptionally complete lifecycle management—snapshots, forks, pause/resume, recovery, resizing—and support for containers, Linux VMs, Windows, and GPUs with straightforward usage pricing.","fix":"Standard organization limits of 4 vCPUs, 8 GB RAM, and 10 GB disk are restrictive for large builds or data-heavy agents."},{"rank":3,"product":"Modal","reason":"Strongest for massive parallelism and compute-heavy agents, with per-second billing, custom images, persistent volumes, GPU access, network controls, and filesystem, directory, and memory snapshots.","fix":"Its default gVisor runtime has Linux syscall compatibility gaps, while the full-VM alternative remains beta and lacks some snapshot and GPU capabilities."},{"rank":4,"product":"Blaxel","reason":"Best persistent-agent design: isolated VMs resume from standby in under 25 ms, scale to zero while retaining memory and filesystem state, and provide MCP, previews, volumes, firewalling, and managed lifecycle APIs.","fix":"It has a smaller ecosystem and shorter production track record than the top three, increasing platform and execution risk for conservative teams."},{"rank":5,"product":"Runloop","reason":"Excellent for software-engineering agents and evaluation fleets, with microVM isolation, blueprints, snapshot branching, suspend/resume, browser support, credential brokering, egress policies, benchmarks, and VPC deployment.","fix":"The most useful production features require the $250/month Pro tier, and its coding-agent specialization makes it less compelling for general-purpose code interpreters."}],"Claude":[{"rank":1,"product":"E2B","reason":"The de facto standard purpose-built for this exact job — open-source Firecracker microVM sandboxes with ~150ms cold starts, first-class Python/JS SDKs, filesystem + process + PTY APIs, pause/resume persistence, and desktop sandboxes; battle-tested at scale by major agent products (Perplexity, Manus-class workloads), so the sharp edges a typical practitioner hits are already sanded down. Near-tie with Modal at the top.","fix":"Self-hosting the open-source stack is genuinely hard (it's designed around their cloud), and long-lived, stateful, or GPU-heavy workloads push you toward pricier or awkward territory — it's optimized for ephemeral interpreter-style runs."},{"rank":2,"product":"Modal","reason":"Sandboxes as a primitive inside a broader serverless platform — gVisor isolation, sub-second starts, easy GPU attachment, image building in code, and massive burst scale, so agent code execution and the rest of your AI infra (batch jobs, inference, training) live in one system with excellent Python DX.","fix":"Proprietary and Python-centric; if all you need is a lightweight code interpreter, you're adopting a whole compute platform, and gVisor's syscall emulation occasionally breaks weird binaries that a real VM would run."},{"rank":3,"product":"Daytona","reason":"Fastest sandbox creation in the field (sub-100ms class), open-source core, declarative images, snapshots, and an API designed agent-first rather than retrofitted; the strongest open alternative if you want control over your stack without building on raw Firecracker yourself.","fix":"Youngest track record of the top three — smaller ecosystem, fewer proven at-scale deployments, and its default container-based isolation is a weaker boundary than microVMs for genuinely hostile multi-tenant code."},{"rank":4,"product":"Cloudflare Sandbox SDK","reason":"Sandboxed code execution co-located with the edge platform many agents already run on — per-sandbox container isolation orchestrated by Durable Objects, preview URLs, a code-interpreter API, and zero extra vendor if you're already on Workers; pricing and global placement are hard to beat for lightweight interpreter workloads.","fix":"Only compelling inside the Cloudflare ecosystem — container resource caps and platform limits make it wrong for heavy, long-running, or GPU workloads, and it's the least mature entry here."},{"rank":5,"product":"Azure Container Apps dynamic sessions","reason":"The enterprise pick — Hyper-V-isolated session pools with sub-second allocation from warm pools, per-second billing, native LangChain/Semantic Kernel integrations, and the compliance/network-integration story (VNet, Entra) that regulated shops require before letting LLM-generated code run anywhere. Rank assumes the practitioner values governance over DX; on pure ergonomics it trails the top three.","fix":"Azure-shaped friction everywhere — clunkier APIs and slower iteration than the startup platforms, and little reason to choose it if you're not already committed to Azure."}],"Gemini":[{"rank":1,"product":"E2B","reason":"Serves as the industry benchmark for lightweight, secure, and developer-friendly ephemeral code execution. Powered by Firecracker microVMs, it offers strong hardware-level isolation, sub-second startup times (~150ms), and seamless API/SDK integration.","fix":"Designed primarily for ephemeral session-based execution, making it poorly suited for persistent, long-running agent workspaces that require complex state persistence across sessions."},{"rank":2,"product":"Upstash Box","reason":"Replaces complex workspace state management by bringing serverless developer mechanics to agent sandboxes, offering durable block storage and auto-scaling to zero when idle with instant wake-ups.","fix":"Not built for high-performance or GPU-backed compute, making it inappropriate for intensive local model training, inference, or heavy mathematical simulations."},{"rank":3,"product":"Modal","reason":"The premier choice for compute-heavy and GPU-intensive agent execution, providing gVisor-based isolation and friction-free serverless access to high-performance GPUs (from T4s to H200s) directly within the secure sandbox.","fix":"Lacks agent-native features like real-time filesystem-watching, live browser previews, or built-in Git workspace state management, requiring significant integration boilerplate."},{"rank":4,"product":"Daytona","reason":"The strongest open-source, self-hostable option for stateful agent workspaces, featuring rapid resume times (~27-90ms) and built-in support for environment snapshots and branching.","fix":"Uses Docker-based isolation by default, which shares the host OS kernel and offers weaker security boundaries compared to hardware-level microVMs."},{"rank":5,"product":"CodeSandbox SDK","reason":"Optimized for AI coding agents that need to build, test, and run full-stack web applications, featuring built-in browser previews, live filesystem watching, and instant snapshotting.","fix":"Higher resource overhead and cost compared to lightweight sandboxes, making it overkill for basic scripting or non-web tasks."}],"Grok":[{"rank":1,"product":"E2B","reason":"Purpose-built for AI agents with Firecracker microVMs for strong kernel-level isolation, excellent Python/JS SDKs, fast boot (~150ms), pause/resume capabilities, and widespread real-world adoption (e.g., Perplexity, enterprise use); open-source core makes it accessible and integrable for typical practitioners needing secure untrusted LLM code execution.","fix":"Session/time limits (e.g., 24h max on many plans) and no native GPU support limit it for long-running or compute-heavy ML tasks."},{"rank":2,"product":"Northflank","reason":"Production-grade microVM options (Firecracker/Kata/gVisor) with unlimited sessions, BYOC/self-hosting, full platform integration (DBs, GPUs, deployments), and strong compliance/isolation for scaling agent workflows beyond prototypes; serves practitioners needing reliable infra.","fix":"Broader platform scope means steeper learning curve for simple code-execution-only use cases."},{"rank":3,"product":"Modal","reason":"Python-first serverless with gVisor isolation, seamless GPU access, dynamic environments, and proven scaling for ML/data pipelines; high value for practitioners doing code execution alongside inference/training in one ecosystem.","fix":"Less specialized for untrusted AI agent code (gVisor vs microVM) and no easy BYOC."},{"rank":4,"product":"Blaxel","reason":"Perpetual sandboxes with sub-25ms resume from standby (zero compute idle cost), microVM isolation, and state preservation tailored for responsive production AI agents; strong for low-latency practitioner workflows.","fix":"Newer entrant with less proven long-term enterprise track record compared to leaders."},{"rank":5,"product":"Daytona","reason":"Fast starts, reproducible/stateful environments with good persistence for development-like agent sessions; solid alternative for speed-focused code execution without heavy overhead.","fix":"Weaker isolation (primarily Docker/containers) vs microVM options for highest security needs."}]},"missedByModel":{"ChatGPT":[{"product":"Cloudflare Sandbox SDK","reason":"excellent VM isolation, global Workers integration, and economics, but Workers lock-in and substantial 2026 API churn reduce general-purpose appeal"},{"product":"Fly Machines","reason":"flexible, proven microVM infrastructure, but practitioners must build much of the agent-specific lifecycle, file, snapshot, and orchestration layer themselves"}],"Claude":[{"product":"Fly.io Machines","reason":"excellent fast-boot Firecracker VMs and a real contender, but it's raw infrastructure — you build the sandbox lifecycle, snapshotting, and agent ergonomics yourself"}],"Gemini":[{"product":"Runloop","reason":"offers strong VM environments but suffers from higher creation latency and cost compared to E2B and Upstash Box"},{"product":"Blaxel","reason":"features impressive sub-25ms startup latency but has a smaller community ecosystem and higher potential idle costs"}],"Grok":[{"product":"Fly.io Sprites","reason":"strong persistence but narrower ecosystem"},{"product":"Vercel Sandbox","reason":"ecosystem-tied, good for web/JS but less general AI agent focus"}]}}