Blaxel vs E2B: Which sandbox fits your agent?

Your coding agent finishes a task, the user closes the tab, and the sandbox keeps billing. Or it pauses, then tomorrow's session starts by re-cloning the repo into a cold environment. Which problem you inherit depends on the sandbox platform underneath your agents.

That lifecycle behavior changes production economics. Coding agents and pull request (PR) review agents spend time waiting on users. Data analysis agents wait on language models, tests, and external APIs. If the sandbox stays active during those waits, you pay for idle compute. If it shuts down too aggressively, users feel the rebuild time when they return.

This comparison focuses on the parts that matter once agents serve real users. Those parts are state persistence, resume latency, networking, procurement, and pricing mechanics.

E2B caps continuous sandbox runtime through its runtime caps. Its Pro plan also adds a monthly floor before compute starts. Blaxel holds sandboxes in standby indefinitely. They resume with filesystem and memory state intact.

Blaxel also ships managed networking. E2B routes those workflows through self-hosted workarounds. Blaxel fits teams running production coding agents, PR review agents, or data analysis agents. E2B fits teams that want open-source infrastructure and sandboxes inside AWS or GCP.

TL;DR:

• Same active rate, different idle cost: Both platforms reach the same normalized compute rate at 1 vCPU and 2 GB. Blaxel suspends automatically and stops billing. E2B bills until you explicitly pause or kill.
• Blaxel for production agents: Perpetual standby with sub-25ms resume, managed custom domains, egress gateways, and proxy secrets injection suit long-lived coding and PR review agents.
• E2B for open-source and BYOC: Apache 2.0 licensing, self-hosting support, and bring-your-own-cloud into AWS or GCP suit teams needing infrastructure custody.
• Session limit tradeoff: E2B enforces a 24-hour continuous cap on Pro and one hour on Hobby. Blaxel has no session time limit.
• Networking gap: Blaxel ships managed custom domains and egress controls. E2B routes custom domains and static IPs through self-hosted proxies.

What is E2B?

E2B is an open-source sandbox platform for running AI-generated code. It uses Firecracker microVMs, which provide hardware-enforced isolation. E2B is operated by FoundryLabs, Inc. out of Prague.

Its SDK and infrastructure are published under the Apache License 2.0. The company raised a $21 million Series A in July 2025. Insight Partners led the round, bringing total funding to $32 million. Production users include Manus, Groq, Lindy, and Perplexity. The main SDK repository gives teams public issues, examples, and implementation details to inspect.

What is Blaxel?

Blaxel is the infrastructure for autonomous agents. Agents execute their code on its infrastructure across compute, storage, and networking. Compute covers Sandboxes and Batch Jobs. Storage covers Agent Drive in private preview and Volumes. Networking includes custom domains, dedicated egress gateways in private preview, and proxy secrets injection.

Blaxel Sandboxes use microVMs built on a custom fork of Firecracker. They stay in standby indefinitely at zero compute cost. When a sandbox resumes, its full filesystem and memory state return intact. Customer examples include Webflow, Delty, and Jazzberry. Jazzberry migrated from a self-managed Firecracker setup to Blaxel.

Blaxel vs E2B: feature comparison

Both platforms use microVM-based isolation. AI-generated code runs in its own sandboxed environment on either one. E2B's model leans toward creating, pausing, and killing sandboxes. Blaxel keeps them alive cheaply across long agent lifecycles.

When Blaxel is the better choice

Choose Blaxel when your agents run in production and their sessions outlive a single execution. Choose Blaxel in these cases:

• Agent sessions that span days or weeks: Coding agents are the clearest case. Blaxel's perpetual standby preserves filesystem, memory, and running processes while idle.
• Multi-tenant products that need production networking: Blaxel ships custom domains as a managed feature. It offers dedicated egress gateways in private preview for static outbound IPs.
• Enterprise procurement: Blaxel supports SOC 2 Type II, ISO 27001, and HIPAA requirements. HIPAA compliance is available through a Business Associate Agreement add-on.
• Fewer systems to operate: Blaxel combines Sandboxes, Batch Jobs, Agent Drive in private preview, Volumes, and Model Gateway. These products cover compute, storage, and model routing on the same backbone.

Long-lived agent sessions

For coding agents, consider a user who generates an app and leaves. They return three days later expecting the same environment. E2B's continuous runtime cap forces pause cycles. Its filesystem persistence also has a documented failure history. GitHub issue #884 tracked file changes being lost after multiple resumes. One customer, Aura's sandbox review, traced a bug to that issue. Webflow uses Blaxel sandboxes for AI coding workflows and real-time previews.

Production networking

Networking becomes more expensive when every tenant needs previews, custom domains, or static outbound IPs. Proxy secrets injection keeps raw API keys out of sandbox code. E2B's docs route custom domains through a self-managed Caddy reverse proxy. Static egress IPs require a self-hosted proxy tunnel. That adds infrastructure your team builds, patches, and monitors.

Enterprise procurement

Procurement changes as agents reach enterprise customers. Blaxel provides native Zero Data Retention (ZDR) options. Its ZDR architecture keeps data on a RAM-based filesystem. E2B lists SOC 2 Type II, HIPAA, and ISO 27001. The available evidence does not show audit dates for them. Security questionnaires close faster when certifications are documented.

Shared storage

Agent Drive in private preview is a distributed filesystem for sharing files across agents and sessions. Its Agent Drive overview explains the cross-session storage model. This reduces the number of systems your team has to connect and support.

Lifecycle, networking, procurement, and shared storage gaps show up once agents serve real users. Production workloads expose failure modes that prototypes often hide.

When E2B may fit better

E2B has strengths around custody, ecosystem depth, and prototyping speed. Teams should weigh them when those areas matter most.

Custody and deployment control

E2B's SDK, code interpreter, and core infrastructure are Apache 2.0 licensed. Its Bring-Your-Own-Cloud offering deploys sandboxes into your own AWS or GCP virtual private cloud. Templates, snapshots, and runtime logs stay inside your VPC. Only anonymized metrics leave for E2B Cloud. That model matters when execution infrastructure must stay under your cloud account.

Blaxel provides public SDKs, documentation, and open-source components. Blaxel also offers private network connectivity on its Custom plan. There is no fully air-gapped, run-it-yourself install. Teams with strict data residency mandates get closer to full custody with E2B's BYOC.

Ecosystem and prototyping speed

E2B's integration ecosystem has also evolved over time. It documents integrations with the LangChain integration, LlamaIndex docs, and Agents SDK. It also offers Model Context Protocol (MCP) tools through its Docker partnership. Its E2B cookbook, large SDK repository, and infra contributors give teams more public examples to inspect.

On language support, E2B ships Python and JavaScript/TypeScript SDKs. Blaxel ships first-class SDKs for Python, TypeScript SDK, and Go. Ruby, Java, and Rust teams integrate with Blaxel through the REST API. E2B also works well for agent prototypes. New sandboxes can spin up in roughly 150ms. Teams can create sessions, test workflows, and shut sandboxes down during development. Friction appears when production sessions must persist across resumes and runtime caps.

Pricing comparison

All figures below are as of July 2026. Where possible, they use a 1 vCPU + 2 GB RAM sandbox. The comparison uses Blaxel's official pricing information and E2B's billing docs.

Active compute

At this configuration, both platforms reach the same normalized active-compute rate. E2B's 1 vCPU configuration is available on both Hobby and Pro. Hobby defaults to 2 vCPU + 512 MiB RAM. A 2 vCPU + 2 GiB E2B configuration would bill at about $0.000037/s.

The active-compute rate is only one part of the pricing decision. Production agents spend meaningful time waiting on users, language models, tests, and remote APIs. Idle billing and base subscriptions decide whether those waiting periods show up as compute spend.

Idle billing

E2B charges for a running sandbox until your code pauses or kills it. The default five-minute timeout kills the sandbox unless you configure auto-pause. Blaxel's network-based lifecycle moves sandboxes to standby after connections close.

That billing behavior changes workload economics. An agent waiting on an LLM response stops costing compute on Blaxel. The same applies to an idle user session. You don't need lifecycle code in the agent to get that behavior. For coding agents or PR review agents, idle time is part of the workload. Users read generated code, reviewers wait for tests, and agents wait on external services. Automatic standby removes that idle compute from the bill without forcing agent-managed pause calls.

Blaxel's pricing structure

Blaxel's pricing structure:

• Free: Up to $200 in free credits plus usage costs.
• Pre-configured sandbox tiers and usage-based pricing: See Blaxel's pricing page for the most up-to-date pricing information.
• Available add-ons: Email support, live Slack support, and HIPAA compliance.

The pricing decision depends less on active compute rate than workload shape. Idle-heavy agents benefit most from automatic standby.

E2B is open source. Why pick a closed platform?

Self-hosting E2B uses Terraform deployments. It officially supports GCP, AWS, Azure, and general Linux machines. The self-hosting guide focuses primarily on GCP. BYOC is available for AWS and GCP.

The orchestrator needs root access for KVM, TAP networking, and cgroup management. If your team won't operate that stack, production E2B is a managed service. In that case, openness acts as insurance rather than a daily advantage. Blaxel's managed layers provide indefinite standby, managed domains, egress gateways in private preview, and secrets injection.

Both start from Firecracker. Doesn't that make them equivalent?

E2B runs open-source Firecracker. Blaxel runs a custom fork it built and maintains independently. The hardware-virtualization boundary is similar, but the lifecycle built around it differs.

E2B pauses at roughly 4 seconds per GiB of RAM. Checkpointing a 4 GiB sandbox takes around 16 seconds. Resume runs about 1 second per its docs.

Blaxel's standby transition is automatic. Its resume latency sits under Jakob Nielsen's 100ms threshold for instantaneous system response. That performance gap comes from engineering the fork specifically for agent workloads: perpetual standby, instant resume, and snapshot management optimized for how agents actually run. When an agent makes dozens of tool calls per session, resume gaps accumulate into visible latency.

E2B has more mindshare. Is Blaxel proven in production?

Webflow runs AI coding workflows on Blaxel. Delty and Jazzberry use Blaxel for PR review automation. Jazzberry also moved from self-managed Firecracker to Blaxel.

Those references matter because production agent workloads fail in practical places. State restoration, networking, support, and idle billing become more important than sandbox creation speed alone.

Test Blaxel vs E2B against your own agent workload

E2B offers open-source code, BYOC into your own cloud, and a broad integration ecosystem. That suits prototyping and teams that need sandboxes inside their own VPC.

Blaxel is the infrastructure for autonomous agents. It provides the execution layer agents depend on to run, connect, and operate at scale. MicroVMs built on a custom Firecracker fork hold standby at zero compute cost. They restore full state and return to standby through network-based auto-shutdown. Speed, persistence, and granular networking control are properties of the runtime itself, not features layered on top.

See the full stack on Blaxel's products page: Sandboxes, Batch Jobs, Agent Drive in private preview, and Volumes. Then run the same agent session on both platforms for a week. Compare the latency, state behavior, and bill. You can sign up free and start with $200 in credits, no credit card required.

FAQs

Is Blaxel cheaper than E2B?

At a normalized 1 vCPU + 2 GB configuration, E2B and Blaxel reach the same active-compute rate. E2B requires Pro to customize CPU or run sandboxes past Hobby limits. Blaxel has no base subscription. E2B bills a running sandbox until it's paused or killed. Blaxel suspends automatically after network inactivity. Blaxel's concurrency tiers start at $20/month for 50 sandboxes. E2B's 100-sandbox cap sits on Pro. Cost depends on workload shape and pricing model.

The main question is how much of the agent session is active execution. If your agent waits on users or LLM responses, automatic standby changes the bill. That pricing difference can matter more than the active-compute rate.

How long can a sandbox stay paused or in standby on each platform?

Blaxel places no limit on standby duration. A sandbox can wait indefinitely with filesystem, memory, and running processes held in standby. You pay only snapshot storage while it is idle. For guaranteed long-term data persistence, use Volumes or Agent Drive in private preview.

E2B's current docs also state paused sandboxes are kept indefinitely at no cost. E2B enforces a 24-hour continuous runtime cap on Pro and 1 hour on Hobby. Its default timeout kills rather than pauses. Pausing also takes about 4 seconds per GiB of RAM.

Do Blaxel and E2B both work with the OpenAI Agents SDK?

E2B added an OpenAI Agents SDK integration in April 2026. Blaxel is a first-class sandbox provider in the OpenAI Agents SDK. Blaxel Sandboxes handle the execution layer beneath OpenAI's Codex harness. The SDK tutorial covers that setup.

If your agent uses the SDK, choose based on standby behavior, networking, compliance documentation, and billing mechanics. SDK compatibility gets the agent connected, but lifecycle behavior decides how the session performs after the first run.

What state survives a resume on each platform?

A Blaxel sandbox resuming from standby restores its exact previous state. That includes all files, memory contents, and running processes. E2B's default pause saves filesystem and memory. Its keepMemory: false mode saves filesystem only, forcing a cold boot.

For coding agents, the difference shows up when a user returns to an existing project. Preserving running processes and memory avoids rebuilding the environment before the agent can continue.