E2B vs Modal Sandboxes vs Daytona: Real AI Agent Sandbox Cost per 10,000 Sessions in 2026

The short answer: E2B and Daytona publish identical raw compute rates, $0.0504 per vCPU-hour and $0.0162 per GiB-hour, so the two are within a rounding error of each other on pure pay-as-you-go pricing. Modal's Sandboxes product is priced separately from — and higher than — its own standard Functions rate, at roughly $0.071 per vCPU-hour equivalent and $0.024 per GiB-hour, making it about 44% more expensive per sandbox-hour than E2B or Daytona on identical resource shapes. E2B's $150/month Pro tier is a pure platform-access fee with no included sandbox-hours bundled in — usage bills in full from the first second on top of it, not as overage past an allowance. At 10,000 short (2-minute) sessions on a 2 vCPU / 4 GiB sandbox, that is $55 on Daytona, $55 on E2B pay-as-you-go (Hobby), or $205 if E2B's $150/month Pro tier is layered on top, and $79 on Modal. At 10,000 longer (20-minute) sessions, the same shapes cost $552 on Daytona, $552 on E2B Hobby, $702 on E2B Pro, and $793 on Modal.

What each vendor bills

E2B (OFFICIAL, e2b.dev/pricing and e2b.dev/docs/pricing, verified against the live pricing calculator). Per-second billing on isolated Firecracker microVMs: vCPU: $0.000014/second ($0.0504/hour) per vCPU. RAM: $0.0000045/second ($0.0162/GiB-hour). Storage: free. Hobby: $0/month, a one-time $100 usage credit for new accounts, 1-hour max sandbox session, up to 20 concurrently running sandboxes, 1 vCPU/512MB default configuration. Pro: $150/month, the same one-time $100 new-account credit (not an additional or recurring allowance), 24-hour max session, up to 100 concurrently running sandboxes, customizable CPU and RAM up to 8 vCPU. Critically, the Pro fee is a platform-access charge only — it does not include any bundled sandbox-hours, and usage bills in full from the first second on top of the $150, the same per-second rate as Hobby. There is no confirmed "overage past an included allowance" mechanism on E2B; any description of Pro as including 500 hours of compute before metering begins does not match the current, officially published pricing model.

Daytona (OFFICIAL, daytona.io/pricing). Identical compute rates to E2B: $0.0504 per vCPU-hour, $0.0162 per GiB-hour, billed per second. No fixed monthly plan is required for production use; new users get a $200 free credit (versus E2B's $100), and startups can qualify for up to $50,000 in credits. Storage beyond the first 5 GiB (included free) is billed at $0.000108 per GiB-hour. Because Daytona has no equivalent platform-access fee to E2B's Pro tier, a low-volume production workload on Daytona avoids the flat monthly charge a comparable E2B Pro deployment carries regardless of usage.

Modal Sandboxes (OFFICIAL, Modal pricing documentation). $0.1419 per physical core-hour (a physical core maps to roughly 2 vCPUs, so the per-vCPU-equivalent rate is about $0.0710), $0.024 per GiB-hour for sandbox memory, and $0.09 per GiB-month for storage beyond 1 TiB included free. Modal's Sandboxes rate is reported to run roughly 3 times its own standard Functions per-core-second rate, and region selection can add a further 1.5–1.75x on top — Sandbox pricing is a distinct, higher-cost product line from Modal's general serverless compute, not the same rate card. Free Starter tier available; Team plan at $250/month for higher limits and collaboration features.

Cost per 10,000 sessions

Formula: total compute-hours = sessions × session minutes ÷ 60; cost = compute-hours × per-hour rate, with E2B Pro's figure additionally adding the flat $150/month platform fee on top of the full usage charge (not as overage past an allowance, but as a separate access fee layered on every dollar of usage).

At the shorter session length, E2B Pro's flat $150 platform fee dominates the bill, nearly quadrupling the cost of the identical workload on Hobby or Daytona — and because Pro buys longer session durations and higher concurrency rather than a usage discount or an included-hours allowance, a low-volume production deployment that only needs Pro's longer session limit or concurrency ceiling pays the full $150 regardless of how light its actual compute usage is.

The idle-versus-active billing distinction

This is the single largest structural difference in this category, and it does not show up in the headline per-hour rate. E2B and Daytona bill wall-clock time: once a sandbox is created, every second counts whether the process inside it is actively computing or waiting on a model response. Modal's Sandboxes bill max(request, actual) per second, which behaves similarly to wall-clock billing in practice for most workloads but is described distinctly in Modal's own documentation. Because AI agents spend a meaningful share of their sandbox lifetime waiting on LLM calls rather than executing code, a wall-clock-billed sandbox left open during that wait time is paying for idle compute the same as active compute — a workload with low CPU utilization during long agent turns costs the same on a wall-clock basis as one running at full utilization for the same duration.

Sensitivity

1. Session duration. Directly and linearly scales cost on every platform; the 20-minute shape costs exactly 10 times the 2-minute shape's raw compute on all three vendors.
2. Whether E2B's Pro tier is needed at all. Since Pro buys longer sessions and higher concurrency rather than a usage discount, a workload that fits within Hobby's 1-hour session limit and 20-concurrent-sandbox ceiling has no reason to pay the $150 flat fee; one that needs 24-hour sessions or more than 20 concurrent sandboxes has no way to avoid it, regardless of actual compute volume.
3. Resource shape (vCPU/memory sizing). A larger sandbox (more vCPU or memory) raises cost proportionally on every vendor; over-provisioning a sandbox for a lightweight agent task is a direct, avoidable cost.
4. Modal's regional multiplier. A reported 1.5–1.75x surcharge for certain regions can push Modal's effective rate meaningfully higher than the base rate used in this article's table.

Budgeting traps

• Assuming E2B's Pro tier includes a bundle of free compute hours. It does not; Pro is a flat platform-access fee for longer sessions and higher concurrency, charged on top of full usage from the first second, not an included allowance with overage after it.
• Comparing Modal's Sandboxes rate to its own Functions rate as if they were the same product. Sandboxes are priced roughly 3x higher, a distinction easy to miss when reading Modal's general compute pricing page.
• Leaving a sandbox open while an agent waits on a model call. Wall-clock billing on E2B and Daytona charges for that idle time identically to active compute time.
• Sizing a sandbox larger than the workload needs. Every unit of vCPU and memory scales cost linearly and immediately on all three platforms.

What to ask before you buy

Confirm whether your workload actually needs E2B Pro's longer session length or higher concurrency ceiling before upgrading from Hobby, since Pro's $150/month buys those specific limits, not a volume discount or included usage. Measure your agent's actual sandbox idle time (time spent waiting on model calls with the sandbox still open) before assuming wall-clock billing charges only for useful compute.