# 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. ``` E2B 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 $2.76 Blaxel Memory 1,000 × 60 s × 4 × $0.0000115 = $2.76 Runtime 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. ```ts check import { 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 ends await 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: ```ts no-run import { Sandbox } from "withruntime/e2b"; // was: from "e2b" ``` ```python no-run from 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. ```python from withruntime import Sandbox with 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](/docs/migrate): 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](/docs/e2b-alternative) and [Runtime vs Blaxel](/docs/blaxel-alternative); [sandbox snapshots](/glossary/sandbox-snapshot) explains what a paused sandbox keeps. ## Sources E2B and Blaxel pricing pages rechecked 25 September 2026; the rest checked 23 September 2026. - [E2B pricing](https://e2b.dev/pricing), [E2B sandbox persistence](https://docs.e2b.dev/sandbox/persistence) - [Blaxel pricing](https://blaxel.ai/pricing), [Blaxel sandboxes](https://docs.blaxel.ai/Sandboxes/Overview) - Runtime [pricing](/docs/pricing) and the [JavaScript guide](/docs/javascript#pause-wake-extend) Facts on this page were checked on 25 September 2026.