So a long wait inside a session costs the same as a long computation. If your workflow pauses often, shut the sandbox down between steps and rebuild state when work resumes, rather than assuming quiet time is free. ### Larger sandboxes multiplying the rate You can match the machine to the job with custom CPU and RAM sizing, but the per-second rate rises with the size you choose. Setting every sandbox to the largest size to be safe multiplies your whole bill by the same factor. Size to the heaviest realistic task, then test whether lighter jobs can run smaller. Because the signup credit is one-time, it won't cover that experimenting for long. Treat it as a trial budget and not a recurring allowance. ### Orphaned E2B sandboxes and cleanup Lose track of a sandbox and it keeps running and keeps billing. Retries cause most orphans. If a request times out and your code retries, the first sandbox may still be alive while the second starts.  Give every sandbox a tag tied to the job that created it, and set a timeout so it ends itself. Run a periodic sweep that lists live sandboxes and kills any with no matching job. Activepieces can run that sweep on a timer, and if the E2B call you need isn't in its catalogue, you can build the missing integration yourself and keep it in your own instance instead of waiting on a vendor release. About 60% of its 746 integrations are community-contributed, counted straight from the open-source monorepo on GitHub, and the core is MIT-licensed. Log creation and teardown for each one, because without those records you can't tell a leak from legitimate load when the invoice arrives. ## E2B, Daytona, Modal and Vercel Sandbox pricing Once your logs give you real sandbox-hours, E2B and Daytona price level at $0.166 an hour for 2 vCPU and 4 GiB. [Modal](https://modal.com/blog/aws-lambda-price-article) sits higher at $0.238, so the hourly rate alone rarely settles the choice. ### Comparison table on price, limits and self-hosting Compare the four vendors in the table on the figures that move a bill. Read the session and concurrency column first, because a cheap rate is worth little if the cap forces you onto a higher plan. | Vendor | Entry price / free credit | 2 vCPU, 4 GiB per hour | Session and concurrency | Self-host | |---|---|---|---|---| | E2B | Free tier with starter credit | $0.166 | Caps rise with plan | Yes, open source | | Daytona | Free credit on signup | $0.166 | Limits set by plan | Yes, open source | | Modal | Monthly free credit | $0.238 | Limits set by plan | No | | Vercel Sandbox | Included usage on the free plan | Metered on active CPU, not a flat hourly rate | Limits set by plan | No | Check each vendor's dated pricing page before you copy any of this into a budget, since entry credit and caps are the cells that change most often. ### When E2B is the cheaper choice Against Modal, E2B wins on raw compute. At $0.166 against $0.238, **Modal costs about 43% more per hour**, which is roughly $72 extra for every 1,000 sandbox-hours. If your agents run many short sessions at steady volume, that gap compounds into a line item worth arguing about. Against Daytona the rates are identical, so E2B is cheaper only if its plan limits fit your workload more tightly. If your sessions are short and your concurrency is modest, you'll likely stay on a lower plan and never meet the cap that triggers an upgrade. With either vendor, self-hosting is also open to you, which matters if your volume is high enough that managed rates stop making sense. ### When Modal or Vercel beats E2B When your workload already lives on Modal, Modal wins. Moving data and functions out to a cheaper sandbox can cost more in engineering time than the $72 per 1,000 hours you save. If your application already runs on Vercel and you want one invoice, Vercel Sandbox wins. Its metering on active CPU makes it hard to compare with a flat hourly rate, though. At low volume the gap stops mattering. A few hundred sandbox-hours a month separates these vendors by a sum smaller than one engineer's afternoon, so pick on limits and fit. ## Monitor E2B spend with Activepieces and a Monday checklist Don't expect Activepieces to make E2B cheaper or lift any of its limits. It watches your usage so the limit that binds you shows up in an alert rather than on an invoice, and it can do that on the Free plan, which is $0 with 1,000 credits a month.  Here the useful part of Activepieces, an automation builder, is small: a scheduled flow that asks E2B what's running and adds up how long it's been running. Flows are unlimited on every plan, including free, so the monitor doesn't compete with your other automations for a flow quota. It then tells you when the total looks wrong. Anything it can't see through E2B's API, it can't warn you about. ### The shape of the workflow, from a screenshot Look at the screenshot for the shape of such a flow in Activepieces' builder. The flow, titled "Site Analysis SEO-ginika," runs four steps in sequence: a weekly schedule trigger, a Firecrawl scrape, an AI page audit and a Google Docs output.  A run costs 1 credit however many steps it has, though AI steps cost more. The trigger's settings panel is open, with day, hour and timezone fields. It is an SEO job, not an E2B monitor. But the structure is the one you need: a trigger on a timer, work in the middle, a result delivered somewhere you'll see it. Because each step carries a "Test me" button, you can run one step against live data before publishing. The unpublished-changes warning at the top is a reminder that nothing runs on schedule until you press Publish. Swap the middle steps for the ones below. ### Stage 1: schedule a daily trigger Use the same schedule trigger shown in the screenshot, but set it to run daily instead of weekly. A weekly check finds a runaway sandbox only after a week of per-second billing has accrued, so the frequency decides how much a mistake can cost. Pick an hour and timezone when you'll actually read the result. ### Stage 2: list running sandboxes with an HTTP step Add an HTTP step that calls E2B's API to list currently running sandboxes, authenticated with your E2B API key stored as a connection or secret, not pasted into the step. Use "Test me" here first. If the response is empty when you know something is running, you have the wrong key or the wrong team, and every later step will report a false all-clear. ### Stage 3: alert when sandboxes run too long Add a code step that reads each sandbox's start time, works out its age and totals the ages. Then add a branch: if the total, or any single sandbox, passes the threshold you chose from your own worked example, send a Slack message or an email. Set the threshold from your expected usage, not from E2B's session limit, because the limit is a ceiling and your budget is lower. Write the sandbox identifiers into the message so you can act without logging in to search. Each Monday, run through this checklist: 1. Confirm the flow is published and the last scheduled runs completed. 2. Check that the alert still reaches a person who will read it. 3. Compare the week's sandbox time against your worked example. 4. Kill any sandbox no one can account for. 5. Revisit the threshold if your usage pattern has changed. ## Frequently asked questions Confirm each answer below against E2B's pricing page and docs before you commit; all are as of 30 October 2026. ### Is E2B free to use? Partly: E2B's free tier comes with a one-time usage credit rather than a recurring allowance, so it covers evaluation, not production. Once the credit is spent, sandboxes bill per second, and the **free tier's session and concurrency limits still apply**. Read the credit's terms on the pricing page before you plan a month around it. If it carries an expiry, an unused balance is worth nothing after that date. ### Does E2B charge for sandboxes that are paused? To keep a sandbox's state without keeping it running, the docs describe pause and resume. Per-second compute is billed while a sandbox runs, so a paused one shouldn't accrue it. Storage is a separate question, and the docs and the pricing page are the place to check how persisted state is treated. Until you have confirmed that, assume paused sandboxes cost something and test with one before you build an idle-sandbox strategy on it. ### Can I self-host E2B to avoid usage fees? You can: E2B's infrastructure is open source, and the docs describe self-hosting on your own cloud account. That removes E2B's per-second fee but moves the cost elsewhere. You pay your cloud provider for the compute, and your team runs, patches and scales the platform. Self-hosting only makes sense if you have the platform engineering to run it, or a volume where the hosted bill clearly exceeds that staffing cost. ### Does E2B offer startup or volume discounts? No volume discount shows in the published tiers, and any discount for startups or heavy users would come through a conversation with E2B's sales team, not a self-serve toggle. If your worked example lands near a plan boundary, ask before you sign. Get any agreed terms in writing, because the pricing page won't record them. ### What happens when I hit the concurrent sandbox limit? Once you hit it, new sandbox creation is refused until a running one ends, so your application needs a queue or a retry path, not an assumption that every request gets a sandbox. The practical consequence is that concurrency, not price per second, is often what forces an upgrade. Look up your plan's limit in the docs, compare it with your peak load, and treat a rejected request as a case to handle in code, not an edge case. ## Related reading - [Best AI Agent Templates to Run Today Without Code](https://www.activepieces.com/blog/best-ai-agent-templates-to-run-today-without-code) - [Jev Agent vs Browser Use: Managed Agent or Free Python Code](https://www.activepieces.com/blog/jev-agent-vs-browser-use-for-ai-automation-in-2026) - [Best Tools for Citizen Developers in 2026](https://www.activepieces.com/blog/tools-for-citizen-developers-in-2024) ## References - [Boxyard](https://boxyard.dev/providers/e2b/pricing) - [E2B](https://e2b.dev/pricing) - [E2B docs](https://docs.e2b.dev/faq/calculate-sandbox-price)You pay for the time a sandbox is running, not the time it's doing work.