Runtime vs E2B

• You pay for the CPU you use. E2B bills every vCPU for as long as the sandbox runs. Runtime measures the CPU your code actually uses. Time spent waiting on a model costs only a small floor, a twentieth of a vCPU.
• Waiting costs storage, not compute. A Runtime sandbox left idle for 300 seconds pauses by itself and keeps its memory. It then pays $0.08 per GB (10⁹ bytes) a month until a request wakes it.
• A written uptime promise. 99% API uptime a month for paid accounts, measured from outside. 10% of a short month's charges comes back as credit automatically (Uptime Promise).
• Lower rates on both meters. $0.025 per vCPU-hour against E2B's $0.0504, and $0.0075 per GiB-hour of memory against $0.0162. Even with every CPU busy the whole time, the example job costs $1.33 on Runtime and $2.76 on E2B.
• No plan fee for long sessions. E2B caps a session at 1 hour on Hobby and needs the $150-a-month Pro plan for 24. A Runtime sandbox has no time limit. It runs while it works. It needs no plan. You add prepaid credit from $10.
• A one-line switch. withruntime/e2b runs code written for E2B's SDK, in JavaScript and Python, including the code interpreter. Credit you add within 30 days of signing up is matched, up to $1,000 in total.
• Teams at no extra charge. Single sign-on over SAML or OIDC (Okta, Microsoft Entra ID, Google Workspace), SCIM, roles and an audit log come with every account (single sign-on). E2B lists SSO, SCIM and roles as planned for its Enterprise plan.
• OpenTelemetry export on every account. Runtime pushes events as logs, and CPU and memory as metrics, to any OTLP endpoint at no charge (observability). E2B sends OTLP metrics and logs on its Enterprise plan.
• Custom domains built in. A paid account serves a sandbox port at your own hostname, with HTTPS, from one command (custom domains). E2B's custom domain guide has you run your own proxy on a virtual machine.
• Secrets stay outside the sandbox. Code inside sees a placeholder. The real key is added at the egress proxy, only on HTTPS to the hosts you allow (security).
• Your agent sets itself up. It runs npx withruntime sandboxes run -- ..., shows you a link, and starts once you approve in the browser. No API key goes into a prompt or a config file. The MCP server reuses the same connection.
• Guardrails for agents. Give an agent a read-only key or a daily spending limit per key. Cap any sandbox's whole cost with maxTotalCostMicros. Every write takes an idempotency key, and the SDKs retry with it. A lost response never creates a second sandbox.

Also included: a code interpreter, network allow and deny lists, custom images, volumes backed up daily, snapshots and forks with memory, private previews, a Linux desktop, metrics, webhooks, S3, R2 and GCS bucket mounts, MCP servers from a catalog and identity tokens for AWS and Google Cloud. Paid accounts add TCP ports, dedicated outbound addresses and WireGuard private networks. See products.

E2B's figures come from its public pricing and documentation, checked 25 October 2026.

Take 1,000 runs of a 2 vCPU, 4 GiB sandbox. Each run lasts 60 seconds and keeps the CPU busy for 20 CPU-seconds. This is an agent that spends most of its time waiting for a model.

• Saving: 77%, or $2.12 per 1,000 runs.
• Per month: at 100,000 runs, $63.89 on Runtime against $276.00 on E2B.
• Busier work: with both CPUs busy for the whole minute, $1.33 on Runtime against $2.76 on E2B. At this size, Runtime is cheaper however busy the sandbox is.

Plan fees, storage, network, taxes and free credits are left out of both. runtime compare --from e2b prices your own usage the same way. Sandboxes the free usage paid for count at the standard rates, so free usage never counts as a saving. On Runtime, inbound traffic is free. Each account's first 100 GiB out a month is free. After that, outbound traffic costs $0.02 per GB (10⁹ bytes). See pricing for Runtime's terms.

Give your coding agent the one instruction in migration. It replaces the E2B calls on a branch, tests them on the free usage, and tells you what you save each month. Your old code stays on the main branch until you merge.

Change one import

Runtime's SDK runs code written for E2B's SDK, as this page describes from version 0.12.0 (Python 0.12.0). Change the import and set RUNTIME_API_KEY:

TypeScriptimport { Sandbox } from "withruntime/e2b"; // was: from "e2b"

Pythonfrom withruntime.e2b import Sandbox  # was: from e2b import Sandbox

withruntime/e2b/code-interpreter and withruntime.e2b.code_interpreter replace E2B's code interpreter packages. Sandboxes get E2B's defaults: 2 vCPU and 512 MiB. Runtime's server stores the timeoutMs you give, up to 24 hours. When it runs out, the sandbox is deleted, as E2B kills it. kill() also deletes it. With no timeout, E2B's 300 seconds ends in a pause instead. The pause keeps memory and files at $0.08 per GB (10⁹ bytes) a month while the account has credit. So call kill() when the work is done. Unlike E2B's, sandboxes pause after 300 seconds with nothing happening and wake on the next call. E2B code still sees them running. runtime: { create: { idlePauseSeconds: 0 } } keeps them running. Sandboxes use the free usage first, then prepaid credit. There is nothing to choose.

commands.run returns the command's whole output. As E2B's does, it throws CommandExitError (Python CommandExitException) on a non-zero exit. It throws TimeoutError (Python TimeoutException) past its timeout. Your existing error handling keeps working. If any output was lost before it was read, the result's truncated is set, and a warning says so.

A call Runtime handles differently, such as E2B templates, workload identity or ending a sandbox earlier than its time limit, throws NotSupportedError before anything happens. It names what to use instead. E2B.md in the package lists every mapping.

Or port the calls

The calls map one to one for most integrations.

E2B:

JavaScriptimport { Sandbox } from "e2b";const sbx = await Sandbox.create();const result = await sbx.commands.run("python3 -c 'print(sum([125, 250, 375]))'");await sbx.kill();

Runtime:

TypeScriptimport { Sandbox } from "withruntime";const box = await Sandbox.create();try {  await box.files.write("/workspace/invoice.py", "print(sum([125, 250, 375]))\n");  console.log((await box.exec("python3 /workspace/invoice.py", { check: true })).stdout);} finally {  await box.stop();}

E2B's commands.run throws CommandExitError on a non-zero exit. Runtime's exec returns the result with exitCode (and timedOut: true on a timeout). With { check: true }, as above, it throws CommandError instead.

• Self-hosting. E2B publishes its runtime under Apache-2.0, so you can run it on your own servers. Runtime is a hosted service.

Checked 23 September 2026; single sign-on, OpenTelemetry and custom domains checked 27 September 2026.

• E2B pricing
• E2B Enterprise
• E2B custom domain
• E2B sandbox persistence
• E2B security
• Runtime pricing, security and products