Best sandbox
for vibe-coded apps
Updated 2026-09-18. E2B is the pick for most projects. Here is how the options compare, and how to run whichever you choose through a single Squiid key.
Short answer
- Our pick: E2B. Purpose-built isolated sandboxes for running code a model wrote, with a filesystem, a process API and a short lifetime, which is exactly the shape of the problem.
- Runner-up: Modal. Run Python functions and jobs in the cloud with GPUs available and scale to zero pricing. Better when the workload is yours and heavy rather than untrusted and short.
- Pick something else when: Browserbase when the sandbox needs to be a real browser for scraping or automation, and RunPod when you want raw GPU time by the hour rather than a function abstraction.
If your app runs code that a language model wrote, run it somewhere isolated, not in your own process. E2B gives you an isolated environment per execution with a filesystem and a clean teardown. The alternatives are for when the code is yours and the constraint is compute rather than trust.
How to choose a sandbox for an AI-coded app
Is the code untrusted?
Model-generated code is untrusted by definition, even when the model is good. It should never run in the same process as your application, with your environment variables in scope. A dedicated sandbox with its own filesystem and no access to your secrets is the baseline.
Cold start time
If a user is waiting for the result, the time to get a sandbox ready is part of the response time. Some platforms start in hundreds of milliseconds, others in tens of seconds. Ask about warm pools if interactivity matters.
Does it need network access?
A code interpreter that can install packages needs outbound network. That is also how data leaves. Decide whether outbound access is allowed, to where, and whether the platform lets you restrict it, before you expose the feature to users.
GPU or CPU?
Running a model, rendering video or training anything needs a GPU, and GPU platforms bill per second at a very different rate. If your workload is data manipulation and charts, CPU sandboxes are an order of magnitude cheaper.
Session lifetime and state
A notebook-style feature needs the sandbox to stay alive between calls and keep variables. A one-shot script does not. Persistent sessions cost more and need explicit cleanup, so pick the model that matches your interaction pattern.
Compare the options
Every sandbox option Squiid carries in the Sandboxes and compute category, with what each one is best at and how it bills.
| Service | Best for | Pricing | On Squiid |
|---|---|---|---|
| Browserbase | Headless browsers in the cloud for agents that click, fill and scrape | both | Roadmap |
| E2B | Secure cloud sandboxes where AI-generated code can actually run | usage | Next up |
| Modal | Serverless GPU and CPU compute defined in Python, billed per second | usage | Roadmap |
| RunPod | On-demand GPU pods and serverless endpoints at community prices | usage | Roadmap |
Why run your sandbox through Squiid
One login instead of one per vendor. Squiid carries 4 sandbox options here and every other layer of the stack beside it. You create one account, click the service you want, and Squiid provisions it upstream. No separate signup, no separate password, no second dashboard.
One bill, at the provider's price. Usage is paid from prepaid Squiid credits at par: $1 of credit is $1 at the provider, with no markup on what the provider charges. The free plan is $0/month with a 15% fee on credit top-ups and a $50 minimum top-up. Solo is $19.97/month and its top-up fee starts at 8%, falling to 6.5%, 5% and 3.5% as trailing 30-day API spend passes $100, $500 and $2,000. Team is $29.97 per seat per month for seats 1-5, $24.97 for seats 6-20 and $19.97 above that, with the same ladder one point lower. Custom pricing is 3% or less against a commitment. Services that are sold as a monthly subscription, such as E2B's paid plan, pass through on your Squiid invoice at the provider's own price with no fee on top.
Squiid holds the upstream key. The provider credential lives in Squiid, not in your repo, not in a chat window and not in a screenshot. Your project gets one variable, SQUIID_API_KEY, and that is the only secret an agent ever needs to see. Rotating it is one click and does not touch the provider.
It works with every coding agent. Point the SDK base URL at https://api.squiid.io/v1/<service>/ and send Authorization: Bearer $SQUIID_API_KEY. Claude Code, Cursor, Codex, Gemini CLI, Copilot, Windsurf, Cline, Devin, Replit, v0 and Lovable all read environment variables the normal way. See the gateway convention.
Running out pauses, it never deletes. Squiid warns you at 75%, 90% and 100% of your balance. At zero, calls pause instead of overdrawing, and your data stays where it is. Auto top-up is optional and takes a hard monthly cap. See spend controls.
Set it up in 3 steps
Add E2B in the dashboard
Create a Squiid account, open the catalogue, and click add on E2B. Squiid creates the upstream account or project for you and holds the credential.
Put one variable in .env
Copy your Squiid key and add SQUIID_API_KEY=sq_live_… to your project's .env. Delete any provider keys you were carrying. Nothing else changes.
Point your agent at the gateway
Tell your agent that calls go to https://api.squiid.io/v1/e2b/ with Authorization: Bearer $SQUIID_API_KEY. Most SDKs take a base URL option, so it is a one-line change.
In practice that is one line in your project:
SQUIID_API_KEY=sq_live_xxxxxxxxxxxxxxxxxxxxThen every call your app or your agent makes goes to the gateway with that one key:
curl https://api.squiid.io/v1/e2b/... \
-H "Authorization: Bearer $SQUIID_API_KEY"Questions people ask
How do I safely run code that an AI generated?
In an isolated sandbox such as E2B, never in your own process. Give the sandbox no access to your environment variables, set a timeout, and restrict outbound network if the code does not need it. Add E2B through Squiid so the sandbox credential stays out of your repo.
E2B or Modal?
E2B when the code is untrusted and short lived, for example a code interpreter feature. Modal when the code is yours and the constraint is compute, including GPU jobs and scheduled batch work. Both are on Squiid under one key.
Can I use a sandbox for browser automation?
Use Browserbase instead. It gives you managed headless browsers with session recording and proxy support, which is a different problem from running a Python script. Trying to install a browser stack inside a generic sandbox is slow and fragile.
Does a sandbox protect me from prompt injection?
It limits the blast radius, it does not prevent the attack. A sandbox stops injected instructions from reading your production secrets or touching your database. You still need to validate what the code is allowed to send back and where it can reach.
How is sandbox time billed through Squiid?
Per second or per run at the provider price, drawn from prepaid credits with no markup. A runaway loop stops when the balance reaches zero rather than continuing to spin up sandboxes, and alerts arrive at 75%, 90% and 100%.
One key for your sandbox.
And everything else.
Add E2B and 107 other services to one account, one key, one bill and one dashboard.