An E2B alternative without the $150/month plan
Both services do the same core thing: an isolated virtual machine, created by API, for running code you do not trust. The difference that decides it for most people is session length. E2B's free tier cuts a sandbox off after an hour, and lifting that means the $150/month Pro plan; here a sandbox runs for 24 hours on any account, with no plan at all. That is not a percentage saving, it is $150 a month against roughly two. The rest is packaging — tiers versus a single flat rate, SDK-first versus REST-and-MCP — and what each of us is honestly better at. Competitor figures below were read from E2B's own pricing and documentation pages on 22 August 2026.
Side by side
| Sandbox as a Service | E2B (published) | |
|---|---|---|
| Pricing model | Prepaid credit, charged for the time a sandbox runs. Fixed size bundles: $0.09/h small, $0.28/h medium, $0.55/h large. | Metered vCPU and RAM: $0.000014/vCPU/s and $0.0000045/GiB/s, plus plan fee. |
| Plan fee | None. One tier. | Hobby $0; Pro $150/month; Ultimate custom. |
| Cost for 2 vCPU / 4 GiB | $0.09/hour, all in. | ≈ $0.17/hour from the published rates, before plan fee. |
| Free to start | $5 of runtime credit (≈ 56 small-sandbox hours), no card required. | One-time $100 in credits on the Hobby tier. |
| Max sandbox lifetime | 24 hours on any account, no plan required. | 1 hour on Hobby; up to 24 hours on Pro. |
| Concurrent sandboxes | 20 per account by default. | Up to 20 on Hobby; up to 100 on Pro, with extra concurrency purchasable up to 1,100. |
| Interfaces | REST API and a hosted MCP server. No SDK packages published yet. | Python and JavaScript/TypeScript SDKs. |
| Exposed ports / preview URLs | None. A server inside a sandbox is reachable only on its own localhost. | Yes — a host and port you can reach from outside. |
| Isolation | One dedicated VM per sandbox, single-tenant, destroyed on expiry. | Isolated VM-based sandboxes; see their docs for current architecture. |
E2B column transcribed from e2b.dev/pricing and docs.e2b.dev on 22 August 2026; the derived hourly figure is our arithmetic on their published per-second rates, not a number they publish. Check both before you decide — rate cards change.
Where the packaging difference bites
The clearest divergence is the plan fee. E2B's published tiers gate two things behind the Pro subscription: sessions longer than an hour, and concurrency above 20. If your workload is a handful of sandboxes that occasionally need to live for a few hours, you are choosing between a $150 monthly commitment and an hourly rate, billed by the second, with no floor. If your workload is hundreds of sandboxes at once, the subscription buys you something we cannot currently offer at all.
The second difference is metering granularity. Metered vCPU and RAM is precise and lets you pay for a 500 MiB machine if that is what you need. Fixed size bundles are blunter, but the whole price of a sandbox is one number you can read off a table, and there is no per-second arithmetic to reconcile against an invoice. Which is better depends on whether you value precision or predictability more.
SDK versus REST
E2B's SDKs are a genuine convenience and we are not going to pretend otherwise. What you get here instead is a surface small enough that the SDK is barely a layer: a handful of endpoints, bearer auth, JSON in and JSON out, with a published OpenAPI document you can generate a client from. For an agent, the MCP server removes the question entirely — the tools are discovered from the server and there is nothing to install.
The same job, here
import os, requests
API = "https://sandbox-as-a-service.com/v1"
H = {"Authorization": f"Bearer {os.environ['AAS_API_KEY']}"}
# Create — no plan tier to pick, no session-length gate.
sbx = requests.post(f"{API}/sandboxes", headers=H,
json={"size": "small", "timeout_minutes": 60}).json()
# Execute — shell command in, structured result out.
r = requests.post(f"{API}/sandboxes/{sbx['id']}/exec", headers=H,
json={"command": "pip install --user -q sympy && "
"python3 -c 'import sympy; print(sympy.isprime(7919))'",
"timeout_ms": 180_000}).json()
print(r["stdout"], r["exit_code"]) # -> True 0
# Destroy — or let the 60-minute timeout do it.
requests.delete(f"{API}/sandboxes/{sbx['id']}", headers=H)const API = "https://sandbox-as-a-service.com/v1";
const headers = {
Authorization: `Bearer ${process.env.AAS_API_KEY}`,
"Content-Type": "application/json",
};
const sbx = await fetch(`${API}/sandboxes`, {
method: "POST",
headers,
body: JSON.stringify({ size: "small", timeout_minutes: 60 }),
}).then((r) => r.json());
const result = await fetch(`${API}/sandboxes/${sbx.id}/exec`, {
method: "POST",
headers,
body: JSON.stringify({ command: "npm i -s left-pad && node -e \"console.log(require('left-pad')('7',3,'0'))\"", timeout_ms: 180000 }),
}).then((r) => r.json());
console.log(result.stdout, result.exit_code);
await fetch(`${API}/sandboxes/${sbx.id}`, { method: "DELETE", headers });Our rate card
| Size | vCPU | Memory | Disk | Price |
|---|---|---|---|---|
small | 2 | 4 GB | 40 GB | $0.09/hour |
medium | 4 | 8 GB | 80 GB | $0.28/hour |
large | 8 | 16 GB | 160 GB | $0.55/hour |
Questions
Where is E2B genuinely the better choice?
Three places, and they are not small. E2B publishes maintained Python and JavaScript SDKs; this service has a REST API and an MCP server but no SDK packages yet, so you write the HTTP calls. E2B's free tier is a one-time $100 in credits against our $5. They expose ports, so a service running inside one of their sandboxes has a reachable URL; we have none, which rules out preview links entirely. Concurrency now matches — 20 sandboxes on their Hobby tier, 20 here — but their Pro tier scales to 100 and beyond, which we cannot. If you need heavy parallel fan-out or a batteries-included SDK today, that is a real difference. (Figures read from e2b.dev/pricing on 22 August 2026.)
How does the cost actually compare?
E2B publishes usage rates of $0.000014/vCPU/second and $0.0000045/GiB/second. For a machine matching our small size — 2 vCPU and 4 GiB — that arithmetic gives about $0.17 per hour, before any plan fee. Our small size is $0.09 per hour all-in. Run the numbers for your own shape rather than taking ours; both rate cards are public.
Do I need a monthly plan to run a sandbox for more than an hour?
Not here. E2B's published tiers put a 1-hour maximum session length on the free Hobby tier and 24 hours on the $150/month Pro tier. This service has one tier: any account can create a sandbox with a lifetime up to 24 hours, and there is no subscription. The lifetime E2B gates behind a $150/month plan is the default here.
Is the isolation model different?
Both run isolated virtual machines rather than shared-kernel containers, so the fundamental boundary is comparable. We can describe ours precisely: one dedicated VM per sandbox, never reused across accounts, destroyed on expiry, code running unprivileged with the cloud metadata endpoint and outbound SMTP blocked. For E2B's current architecture, read their documentation rather than our summary of it.
Can I migrate an existing E2B integration?
The concepts map directly — create a sandbox, run commands in it, tear it down — so the work is replacing SDK calls with HTTP calls: create, exec, the filesystem endpoints, and destroy. The parts that need attention are lifetime handling (our maximum is 24 hours) and concurrency (20 per account by default). Anything relying on E2B-specific higher-level features has no direct equivalent here.
Why should I trust a smaller service?
Judge it on what is checkable rather than on size. The API is small enough to read in one sitting and has a published OpenAPI spec, pricing is a flat hourly rate billed by the second with no plan fee, there is no contract, and credit is prepaid so the maximum you can lose is what you have topped up. We claim no certifications and no uptime guarantee, and we would rather say that than imply otherwise.
Compare it on your own workload
A dollar of credit is enough to run your actual job here and read the invoice. No card, no plan.