E2B vs Blaxel: pricing, isolation and limits

A 2 vCPU, 4 GB sandbox costs the same on E2B and Blaxel, $0.1656 an hour. Blaxel bills memory only and goes to standby by itself.

Runtime runs the same job for 77% less than either. 1,000 one-minute runs of a 2 vCPU, 4 GiB sandbox cost $2.76 on E2B, $2.76 on Blaxel and $0.64 on Runtime, because Runtime bills the CPU your code uses instead of the size it holds, and prices memory at under half of E2B's rate. Rates checked 23 September 2026.

At a glance

	E2B	Blaxel	Runtime
Isolation	Firecracker microVM, own kernel	Lightweight virtual machines	Firecracker microVM, own kernel
CPU	$0.0504 per allocated vCPU-hour	Included with memory; 8 GB gets 4 cores	$0.025 per vCPU-hour of measured CPU, with a small floor
Memory	$0.0162 per GiB-hour	$0.0000115 per GB-second of active time ($0.0414 an hour)	$0.0075 per reserved GiB-hour
Sizing	1 to 8 vCPUs and 1 to 8 GiB, chosen apart	CPU follows memory	vCPUs and memory chosen apart
When idle	Pause keeps files, memory and processes	Standby by itself; no compute charge; resumes in about 25 ms	Pause keeps files, memory and processes, 1 to 365 days
Idle storage	Included with every plan	$0.20 per GB-month of standby snapshot	$0.08 per GB-month
Plan fee	Hobby $0; Pro $150 a month	None; tiers grow with credit added	None; prepaid credit from $10
Free start	$100 of usage credit, once	Up to $200 of credit	50 sandbox hours, no card
Concurrency	20 on Hobby, 100 on Pro, more as add-ons	10 on the free tier, over 100,000 at the top tier	8 on the trial, 100 paid to start, raised on request
Session length	1 hour on Hobby, 24 hours on Pro	No limit stated; seconds to days	Leases of up to an hour, extended as often as needed

Why do E2B and Blaxel cost the same?

Their rates meet at two gigabytes per core. E2B charges 2 × $0.0504 for the vCPUs and 4 × $0.0162 for the memory of a 2 vCPU, 4 GiB sandbox: $0.1656 an hour. Blaxel charges only for memory, 4 GB × $0.0414, and gives it 2 cores: also $0.1656 an hour. The same holds at 4 vCPUs and 8 GB, $0.3312 an hour on both.

They part when a job wants a different mix. On Blaxel, CPU comes from memory, so a job that needs 4 cores pays for 8 GB even if it uses 2. On E2B you set vCPUs and memory apart, so 4 vCPUs with 4 GiB costs $0.2664 an hour. And they part when the sandbox goes quiet: Blaxel stops charging for compute once a sandbox is in standby, while E2B bills until the sandbox is paused, killed or timed out.

Runtime sets vCPUs and memory apart like E2B, and bills CPU only as it is used, so the waiting part of a run costs a small floor rather than the full size.

Cost for the same job

1,000 runs of a 2 vCPU, 4 GiB sandbox (4 GB on Blaxel). 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                                        $2.76Blaxel   Memory 1,000 × 60 s × 4 × $0.0000115      = $2.76Runtime  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 or Blaxel 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 $2.76 on Blaxel, so Runtime is cheaper however busy the sandbox is. The Blaxel figure assumes each sandbox enters standby the moment its run ends; Blaxel's docs say standby starts about 15 seconds after the last connection closes. Plan fees, storage, network and free credits are left out.

What does an idle sandbox cost?

On Blaxel, nothing for compute: a sandbox goes to standby when its connections close and resumes in about 25 ms, and its standby snapshot costs $0.20 per GB a month. On E2B, a paused sandbox keeps its files, memory and running processes with no expiry.

A paused Runtime sandbox keeps files, memory and processes for $0.08 per GB a month, and, like Blaxel's standby, any request to it wakes it: an exec, a file call or a visit to a shared port.

TypeScriptimport { Sandbox } from "withruntime";const sbx = await Sandbox.create({ timeoutSeconds: 600 });await sbx.exec("echo state > /workspace/state.txt");await sbx.pause(); // memory and files are kept; compute billing stops// ... later, even from another process:const again = await Sandbox.connect(sbx.id);await again.wake({ timeoutSeconds: 1200 });await again.extend(600); // more time before the lease endsawait again.stop();

Which one to pick

• Pick E2B to choose vCPUs and memory separately, keep paused sandboxes with no expiry, or self-host its Apache-2.0 runtime.
• Pick Blaxel for sandboxes that idle for free and come back in about 25 ms, or fleets beyond 100,000 at once on its top tier.
• Pick Runtime for under a quarter of either price on an agent that waits, vCPUs and memory chosen apart, paused storage at $0.08 per GB-month, and an agent that connects without an API key.

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 Blaxel, create, exec, file and delete calls map to Sandbox.create(), exec, files.write and files.read, and stop(). Standby needs no call: automatic wake is on by default, and idlePauseSeconds pauses a sandbox after the idle time you choose.

Pythonfrom withruntime import Sandboxwith Sandbox.create(funding="trial") as box:    print(box.exec("python3 -c 'print(6 * 7)'", check=True).stdout)

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 Blaxel; sandbox snapshots explains what a paused sandbox keeps.

Sources

E2B and Blaxel pricing pages rechecked 25 September 2026; the rest checked 23 September 2026.

• E2B pricing, E2B sandbox persistence
• Blaxel pricing, Blaxel sandboxes
• Runtime pricing and the JavaScript guide

Facts on this page were checked on 25 September 2026.