E2B vs CodeSandbox: pricing, isolation and limits

Both run Firecracker microVMs. E2B bills vCPUs and memory by the second; CodeSandbox bills a fixed VM size by the minute, rounded up.

Runtime runs the same job for 77% less than E2B and 74% less than CodeSandbox. 1,000 one-minute runs of a 2 vCPU, 4 GiB sandbox cost $2.76 on E2B, $2.48 on a CodeSandbox Nano VM and $0.64 on Runtime. Runtime bills the CPU your code uses, by the second, and has no plan to buy for more than ten sandboxes at once. Rates checked 23 September 2026.

At a glance

CodeSandbox's rates are from Together's documentation of the CodeSandbox SDK; CodeSandbox is a Together company.

	E2B	CodeSandbox SDK	Runtime
Isolation	Firecracker microVM, own kernel	Firecracker microVM	Firecracker microVM, own kernel
Price	$0.0504 per vCPU-hour, $0.0162 per GiB-hour	Credits by VM size; Nano (2 cores, 4 GB) $0.1486 an hour	$0.025 per vCPU-hour of measured CPU, $0.0075 per GiB-hour
Billing unit	Per second	Per minute, rounded up	Per second
Sizes	1 to 8 vCPUs and 1 to 8 GiB, set apart	Fixed sizes from Pico to XLarge, up to 64 cores and 128 GB	vCPUs and memory chosen per sandbox
Plan fee	Hobby $0; Pro $150 a month	Build free; Scale $170 a month	None; prepaid credit from $10
At once	20 on Hobby, 100 on Pro, more as add-ons	10 VMs on Build, 250 on Scale	8 on the trial, 100 paid to start, raised on request
Free start	$100 of usage credit, once	The free Build plan	50 sandbox hours, no card
Session length	1 hour on Hobby, 24 hours on Pro	Not stated in the pricing docs	Leases of up to an hour, extended as often as needed
Saved state	Pause keeps files, memory and processes	Memory snapshot and restore; resume or clone in about 3 s	Pause, snapshots and forks keep memory and processes

Is CodeSandbox cheaper than E2B for AI agents?

Slightly, for runs that last whole minutes. A Nano VM, 2 cores and 4 GB, is 10 credits an hour at $0.01486 a credit: $0.1486 an hour. The same size on E2B is 2 × $0.0504 plus 4 × $0.0162, $0.1656 an hour. Both charge that whether the code is working or waiting.

Short runs change the answer. CodeSandbox counts VM time in whole minutes, rounded up, and E2B bills by the second. 1,000 runs of 40 seconds each cost $1.84 on E2B and still $2.48 on CodeSandbox, because each one is billed as a full minute. For agents that start a sandbox, run one command and stop it, that rounding decides the bill.

The other differences are sizing and concurrency. E2B lets you set vCPUs and memory separately up to 8 each. CodeSandbox sells fixed sizes, much larger at the top end, and more than 10 VMs at once needs the $170-a-month Scale plan; E2B's Hobby plan allows 20 at once and Pro 100.

Runtime bills by the second, like E2B, and bills only the CPU a run uses. The same 1,000 runs of 40 seconds cost $0.47 on Runtime.

Cost for the same job

1,000 runs of a 2 vCPU, 4 GiB sandbox (a Nano VM on CodeSandbox). Each run lasts 60 seconds and keeps the CPU busy for 20 CPU-seconds: an agent that mostly waits for a model.

TextE2B          CPU    1,000 × 60 s / 3,600 × 2 × $0.0504 = $1.68             Memory 1,000 × 60 s / 3,600 × 4 × $0.0162 = $1.08             Total                                        $2.76CodeSandbox  Size   1,000 × 60 s / 3,600 × $0.1486     = $2.48Runtime      CPU    1,000 × 20 s / 3,600 × $0.025      = $0.14             Memory 1,000 × 60 s / 3,600 × 4 × $0.0075 = $0.50             Total                                        $0.64

At 100,000 runs a month that is $276.00 on E2B, $247.67 on CodeSandbox and $63.89 on Runtime. With both CPUs busy for the whole minute, it is $1.33 on Runtime against $2.76 on E2B and $2.48 on CodeSandbox, so Runtime is cheaper however busy the sandbox is. Each run is a whole minute here, so CodeSandbox's rounding adds nothing. Plan fees, storage, network and free credits are left out.

Which one to pick

• Pick E2B for per-second billing on sandboxes you size yourself, 20 sandboxes at once on a free plan, or a runtime you can self-host under Apache-2.0.
• Pick CodeSandbox for very large VMs, up to 64 cores and 128 GB, Dev Container support, or 250 VMs at once on a single plan.
• Pick Runtime for per-second billing on measured CPU at under a quarter of either price, 100 sandboxes at once with no plan fee, and forks that copy a running sandbox with its memory.

Switch from either one

From E2B, Runtime's SDK runs your code after one import change:

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

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

From CodeSandbox, map the usual calls: create a sandbox with Sandbox.create(), run commands with exec, move files with files.write and files.read, and end it with stop(). A VM you hibernate becomes a sandbox you pause() and wake(), and a fork from a template becomes fork, which copies a running sandbox with its memory:

TypeScriptimport { Runtime, Sandbox } from "withruntime";const runtime = new Runtime();await using base = await Sandbox.create();await base.exec("pip install --quiet requests");const [a, b] = await base.fork({ count: 2 }); // both running, answered togetherawait Promise.all([a!.stop(), b!.stop()]);// Or keep the machine to start copies from later:const snapshot = await base.snapshot({ name: "with-requests", retentionDays: 7 });await using later = await runtime.sandboxes.create({ snapshot: snapshot.id });await runtime.snapshots.delete(snapshot.id);

Or give your coding agent the one instruction in migration: it switches the project on a branch, tests it on the free trial and reports the monthly saving. The full side-by-sides are Runtime vs E2B and Runtime vs CodeSandbox; what a sandbox fork is covers forks in more depth.

Sources

E2B pricing and Together's Code Sandbox documentation rechecked 25 September 2026; the rest checked 23 September 2026.

• E2B pricing, E2B sandbox persistence
• Together Code Sandbox, CodeSandbox SDK pricing
• Runtime pricing and the JavaScript guide

Facts on this page were checked on 25 September 2026.