Which sandbox providers offer “billed per second”?

Usage is counted to the second rather than by the hour or month. Fully: Blaxel, Boat, Cloudflare Sandbox, Daytona, E2B, InstaBox, Lizard, Modal, Morph, Runtime, Sandboxer, Sprites, Tensorlake and boxd. With a catch: Vercel Sandbox. Not at all: Agent 37.

Which sandbox providers offer “cPU billed only while working”?

An idle processor costs nothing or very little. Fully: Cloudflare Sandbox, Runtime, Sprites, Tensorlake and Vercel Sandbox. Not at all: Agent 37, Blaxel, Boat, Daytona, E2B, InstaBox, Lizard, Modal, Morph, Sandboxer and boxd.

Which sandbox providers offer “paused costs only storage”?

A paused or stopped machine bills for its kept files only, not CPU or memory. Fully: Agent 37, Blaxel, Boat, Cloudflare Sandbox, Daytona, E2B, InstaBox, Lizard, Morph, Runtime, Sandboxer, Sprites, Tensorlake and Vercel Sandbox. With a catch: boxd. Not at all: Modal.

Which sandbox providers offer “no monthly fee”?

Pay only for what you use, with no plan fee. Fully: Agent 37, Blaxel, Daytona, E2B, Modal, Morph, Runtime, Sprites, Tensorlake and boxd. With a catch: Vercel Sandbox. Not at all: Boat, Cloudflare Sandbox, InstaBox, Lizard and Sandboxer.

Which sandbox providers offer “flat monthly price”?

A fixed price per month for a machine, so the bill is predictable. Fully: Boat, Lizard and Sandboxer. Not at all: Agent 37, Blaxel, Cloudflare Sandbox, Daytona, E2B, InstaBox, Modal, Morph, Runtime, Sprites, Tensorlake, Vercel Sandbox and boxd.

Billing models

The idea

Flat per size: you pick a fixed shape and pay an hourly rate for it whether it works or waits. Boat, Sandboxer and Lizard work this way. It is the easiest to predict and the easiest to compare.

Per vCPU and per GB: the rate is a sum of parts, so much per vCPU-hour, per GB-hour of memory and per GB-month of disk. Agent 37, InstaBox, E2B and Vercel work this way, and boxd uses three meters of its own. It is flexible and hard to compare, because two providers can quote the same hourly number for different amounts of memory.

A plan fee that returns as credit: Sandboxer, InstaBox, Lizard and Boat sell a monthly plan whose dollars convert into usage. That is not a fee, but it is a floor: a light month still costs the plan price, and unused plan time usually expires. Morph's MCU model is a fourth shape: the rate is the largest resource dimension, not the sum.

Where providers split

The claim on the left, the provider's own words on the right

Reserved size versus measured use

A flat rate bills the shape you reserved. A measured meter bills what the machine used, which can be much less or much more than the shape suggests. Runtime bills measured active CPU with a 50-millicore floor plus reserved memory. Sprites bills actual CPU and actual memory. Vercel bills active CPU excluding I/O wait, plus provisioned memory.

The difference is largest for an agent waiting on a model. Runtime's floor makes an idle-but-running box cost about $0.03 an hour; a flat 2 vCPU / 4 GiB shape costs its full hourly rate whether it waits or not.

The plan is a floor, not a fee

Boat's $20 plan buys $20 of VM time, and unused time expires monthly. Sandboxer's $20 buys about 555 default-hours, and the plan converts into machine time. InstaBox and Lizard treat the fee as a monthly credit that resets.

The trap is a workload that costs $3 of usage and still bills $20. That is not a pricing error; it is the floor doing its job.

What is still charged while stopped

Agent 37, InstaBox and Runtime charge storage. Sandboxer counts stopped storage against a free quota. Boat charges nothing and keeps the disk for 14 days. boxd charges for written disk in every state and for memory in standby. Lizard's stop deletes the sandbox. E2B does not bill paused or killed sandboxes, but volumes and snapshots are separate.

Vercel is the one to read carefully: persistent sandboxes save a snapshot on stop, and snapshot storage bills separately from compute.

One worked case

The same job at every provider, from the documented defaults

One month of a box that mostly waits

A 2 vCPU / 4 GB sandbox runs for 730 hours. The agent is busy for about 5% of that time and waits on a model for the rest. Nothing else changes.

Hour 1
The machine is created and the agent starts. The meter is either the shape you reserved or the resources it uses.
Hour 100
The agent has been idle for most of it. On a reserved meter the bill is already fixed; on a measured meter it is nearly zero.
Hour 730
The invoice arrives, and the plan floor decides whether a cheap month is cheap.

Two providers can quote the same hourly number for different amounts of memory. What separates them is whether the meter follows the reserved shape, the measured CPU, or the resident memory — and what the plan floor does to a light month.

What each provider does

Agent 37: Priced from the reserved shape — $0.80 per vCPU-month and $0.70 per GB-month — so waiting costs the same as working.
Blaxel: Billed on allocated RAM per second with CPU included, so a waiting box pays for its whole memory allocation.
Boat: A flat hourly rate per size, $0.036 for the default 4 vCPU / 8 GB, whether it waits or works.
boxd: vCPU on the size while running, RAM on resident memory, disk on bytes written, so a waiting box pays for what it holds.
Cloudflare Sandbox: The waiting box pays memory and disk but no CPU; the busy box pays active CPU on top.
Daytona: The waiting box pays for its reserved 2 vCPU and 4 GiB every second; stopped, it pays disk only.
E2B: Per second of allocated vCPU and RAM while running, so the reserved shape sets the bill even when the agent waits.
InstaBox: A plan that is also credit, then per-second vCPU and RAM; a light month still costs the plan.
Lizard: A flat hourly price per size, billed per second including idle, inside a $19 plan that includes $19 of usage.
Modal: The waiting box pays max(request, actual), so idle time inside the request bills at full rate; only termination stops the meter.
Morph: MCUs where the rate is the largest resource dimension, so a memory-heavy idle box pays on memory.
Runtime: Measured active CPU above a 50-millicore floor plus reserved memory, so waiting costs about $0.03 an hour.
Sandboxer: A monthly plan whose dollars return as machine time at a fixed multiplier per size; stopped time is free.
Sprites: Actual CPU at $0.0385 per CPU-hour and actual memory at $0.021875 per GB-hour, so a waiting Sprite is cheap but not free.
Vercel Sandbox: Active CPU excluding I/O wait plus provisioned memory, so memory is paid for while the CPU waits.
Tensorlake: Per-second metering at $0.07 per active core-hour, $0.015 per GB-hour of RAM and $0.0002 per GB-hour of disk, or 40% less on Pro.

What to watch for

The details that decide the answer in practice

01
Whether the meter measures reserved size, actual CPU, or resident memory.
02
Whether the monthly fee returns as usage, and what expires at month end.
03
What is charged while stopped: compute, memory, storage, or nothing.
04
Which costs are absent from the pricing page: egress, snapshots, static IPs.
05
Whether there is a minimum billed duration or a one-minute increment.

Compare all 16

Docs read 28 October 2026

The meter decides your bill more than the hourly rate does. Four shapes are in play: flat per size, per vCPU and per GB, a plan fee that returns as credit, and measured CPU.
Provider	The meter	Does it?	What that means
Agent 37	$0.80/vCPU-month	Yes	Prepaid wallet, per minute, priced from the reserved shape: $0.80 per vCPU-month, $0.70 per GB-month, $0.09 per GB-month of disk. No plan fee, no minimum, stopped time is disk only.Agent 37 docs: Billing — prepaid wallet, per-minute metering and managed usage ↗ Agent 37's own wordsdocs-confirmed “vCPU \| $0.80 per vCPU per month” Agent 37docs-confirmed
Blaxel	$0.0000115/GB-second	Partly	Active compute is billed on allocated RAM per second at $0.0000115 per GB-second, with CPU included. Snapshots and volumes bill separately; tiers are wallet top-ups, not subscriptions.Blaxel docs: Pricing ↗ Blaxel's own wordspricing-page “$0.0000115 / GB RAM · second” Blaxelpricing-page
Boat	$0.036/h default	Partly	A monthly plan that is prepaid machine time plus limits, with a separate dollar wallet for overage. Per second while running; stopped is zero machine time and the disk is kept 14 days.Boat docs: Plan, wallet and running out ↗ Boat's own wordspricing-page “VM time past the included time \| $0.036 per hour of default” Boatpricing-page
boxd	Three meters	Partly	Prepaid credits and three meters: vCPU on the size while running, RAM on resident memory (also in standby), disk on bytes written in every state. No plan fee; storage prices are unpublished.boxd docs: Pricing and the billing FAQ ↗ boxd's own wordspricing-page “RAM bills on the memory a machine actually has resident, sampled every second, while it is running or in standby” boxdpricing-page
Cloudflare Sandbox	$0.072/vCPU-hour active	Partly	Per 10 ms while running: active CPU $0.072/vCPU-hour, provisioned memory $0.009/GiB-hour and provisioned disk $0.000252/GB-hour. A stopped instance bills nothing.Cloudflare Sandbox docs: Containers pricing ↗ Cloudflare Sandbox's own wordspricing-page “Memory and disk usage are based on the provisioned resources for the instance type you select, while CPU usage is based on active usage only.” Cloudflare Sandboxpricing-page
Daytona	$0.0504/vCPU-hour	Partly	Reserved vCPU at $0.0504/hour, memory at $0.0162/GiB-hour and disk at $0.000108/GiB-hour, billed per second with no plan fee. Windows adds $0.0858/vCPU-hour, which may replace or add to the Linux rate.Daytona docs: Billing (what each state bills) ↗ Daytona's own wordspricing-page “vCPU $0.0504/h” Daytonapricing-page
E2B	$0.000014/vCPU-s	Partly	Per second of allocated vCPU and RAM while running, against a credit balance. Paused and killed sandboxes are not billed. Pro adds a $150 monthly fee; Hobby has a one-time $100 credit.E2B docs: Billing & limits ↗ E2B's own wordspricing-page “$0.000014 per vCPU-second” E2Bpricing-page
InstaBox	$20 plan, then usage	Yes	A subscription that is also credit: $20, $100 or $500 a month, then per-second vCPU and RAM, GiB-hour storage and $0.02 per GiB of egress. Paused and stopped machines pay storage only.InstaBox docs: Pricing — plans, credits and unit rates ↗ InstaBox's own wordspricing-page “$20 / month free credits” InstaBoxpricing-page
Lizard	$19 planflat per size	Partly	One $19 plan including $19 of usage; sandboxes are a flat hourly price per size, billed per second including idle, and volumes bill on used space. Snapshot storage has no published price.Lizard docs: Billing — Pro, trial, usage rates and overage ↗ Lizard's own wordspricing-page “Pro costs $19 a month and includes $19 of usage for the whole platform: apps, databases, Sandboxes, storage and egress.” Lizardpricing-page
Modal	$0.141912/core-hour	Partly	Per second on the higher of request and actual use: CPU $0.141912/core-hour and memory $0.024012/GiB-hour at the non-preemptible sandbox rate, 3× list. Disk is billed as memory at 20:1.Modal docs: Billing ↗ Modal's own wordsdocs-confirmed “Modal Sandboxes are billed by the second based on whichever is higher: your resource request or your actual usage.” Modaldocs-confirmed
Morph	$0.05/MCU-hour	Partly	MCUs where the rate is the largest resource dimension: 1 vCPU-hour, 4 GB RAM-hours, 16 GB disk-hours or 5 TB snapshot-hours, at $0.05 per MCU-hour. Plans include MCU allocations.Morph docs: Plans ↗ Morph's own wordspricing-page “standard MCU rate of $0.05” Morphpricing-page
Runtime	50-millicore CPU floor	Partly	Prepaid credit, per second: measured active CPU above a 50-millicore floor, plus reserved memory, plus storage while paused or stopped. No plan fee; plans are in a private beta.Runtime docs: Understand your sandbox bill ↗ Runtime's own wordsinferred “Measured CPU use above a 50-millicore floor” Runtimeinferred
Sandboxer	$0.036/h default	Partly	A monthly plan whose dollars return as machine time, metered per second at a fixed multiplier per size. Stopped time is free, but the $20 plan is a floor and plan time expires monthly.Sandboxer docs: Billing ↗ Sandboxer's own wordspricing-page “\| default \| 4 \| 8 GB \| 50 GB \| 1× \| $0.036 \| $26.28 \|” Sandboxerpricing-page
Sprites	$0.0385/CPU-hour	Partly	Actual CPU at $0.0385 per CPU-hour and actual memory at $0.021875 per GB-hour, plus hot and cold storage. The pricing page says there are no plans; the product FAQ describes plans.Sprites docs: Fly.io Pricing — Sprites ↗ Sprites's own wordspricing-page “$0.0385 / CPU-hour” Spritespricing-page
Vercel Sandbox	$0.128/CPU-hour	Partly	Active CPU at $0.128 per CPU-hour excluding I/O wait, provisioned memory at $0.0212 per GB-hour with a one-minute minimum, plus creations, transfer, snapshots and drives.Vercel Sandbox docs: Sandbox pricing and quotas ↗ Vercel Sandbox's own wordspricing-page “Sandbox Active CPU \| 5 hours/month \| $0.128/hour \| $0.128/hour” Vercel Sandboxpricing-page
Tensorlake	Active CPU$250 Pro	Yes	Prepaid Usage Credits in $5–$20 packs (1 CU = $0.01) or Pro at $250 including 25,000 CU. CPU bills only while it executes, falling back to allocated vCPU time when sampling fails; RAM and disk bill on allocation while running; a suspended sandbox bills snapshot storage at $0.07 per GB-month; egress is free.Tensorlake docs: Pricing and billing — prepaid credits, Pro rates and metering ↗ Tensorlake's own wordspricing-page “CPU tracks active runtime execution when metering is available, rather than reserved vCPU time.” Tensorlakepricing-page

The specific capabilities

Each one checked for every provider, with the catch where a version falls short. All capabilities

Billing models: capabilities by provider
Capability	Agent 37	Blaxel	Boat	boxd	Cloudflare Sandbox	Daytona	E2B	InstaBox	Lizard	Modal	Morph	Runtime	Sandboxer	Sprites	Tensorlake	Vercel Sandbox
Billed per second	Agent 37: No. per minute. Usage is counted by the minute, not the second, so every short task rounds up.	Blaxel: Yes. per second	Boat: Yes. per second	boxd: Yes. per second	Cloudflare Sandbox: Yes. per 10 ms	Daytona: Yes. per second	E2B: Yes. per second	InstaBox: Yes. per second	Lizard: Yes. per second	Modal: Yes. per second	Morph: Yes. per second	Runtime: Yes. per second	Sandboxer: Yes. per second	Sprites: Yes. per second	Tensorlake: Yes. per second	Vercel Sandbox: With a catch. memory rounds to a minute. Memory is counted in whole minutes, so a 20-second task is charged for a full minute of memory.
CPU billed only while working	Agent 37: No. full rate while awake. A running machine pays its full compute rate whether it is working or waiting.	Blaxel: No. memory-based meter. The meter runs on the memory you allocated for as long as the sandbox is active, busy or not.	Boat: No. flat rate per size. A running machine costs the same whether it is working or waiting.	boxd: No. full cores while running. The processor is charged at the machine's full size for as long as it runs.	Cloudflare Sandbox: Yes. active CPU only	Daytona: No. reserved size. You pay for the cores and memory you reserved, not the ones the work used.	E2B: No. allocated size. The bill follows the cores and memory you gave the machine, not what it used.	InstaBox: No. size while running. A waiting machine costs the same as a busy one of the same size.	Lizard: No. idle is billed. Waiting time is charged at the same rate as working time.	Modal: No. request or use, whichever is higher. A machine that reserves more than it uses pays for the reservation.	Morph: No. largest resource counts. The rate follows the largest of cores, memory and disk, so spare capacity is paid for.	Runtime: Yes. measured, 50 mcore floor	Sandboxer: No. flat rate per size. The price depends on the size you picked, not on how hard it works.	Sprites: Yes. actual CPU	Tensorlake: Yes. active CPU only	Vercel Sandbox: Yes. active CPU only
Paused costs only storage	Agent 37: Yes. disk only	Blaxel: Yes. storage only	Boat: Yes. nothing for 14 days	boxd: With a catch. pause keeps paying for memory. Pausing keeps the memory in place and you keep paying for it; only hibernating or stopping brings the bill down to disk alone.	Cloudflare Sandbox: Yes. nothing while stopped	Daytona: Yes. disk only	E2B: Yes. nothing while paused	InstaBox: Yes. storage only	Lizard: Yes. compute stops	Modal: No. no pause. There is no pause: a sandbox bills until it is shut down, and its saved copy is stored separately.	Morph: Yes. snapshot only	Runtime: Yes. storage only	Sandboxer: Yes. nothing while stopped	Sprites: Yes. compute stops	Tensorlake: Yes. storage only	Vercel Sandbox: Yes. compute stops
No monthly fee	Agent 37: Yes. none	Blaxel: Yes. none	Boat: No. $20 minimum plan. The smallest plan is $20 a month, and unused time expires, so a light month still costs $20.	boxd: Yes. none	Cloudflare Sandbox: No. $5 Workers plan. Sandboxes need the $5-a-month Workers Paid plan before anything can run.	Daytona: Yes. none	E2B: Yes. none on Hobby	InstaBox: No. $20 minimum plan. The free plan is capped at one machine, and anything more needs a $20-a-month plan.	Lizard: No. $19 plan. There is one plan at $19 a month, which includes $19 of usage.	Modal: Yes. Starter $0	Morph: Yes. Developer $0	Runtime: Yes. none	Sandboxer: No. $20 minimum plan. The smallest plan is $20 a month, and included time does not carry over.	Sprites: Yes. none	Tensorlake: Yes. prepaid credit	Vercel Sandbox: With a catch. Hobby free; Pro $20. The free Hobby plan is for personal projects only; commercial use needs the $20-a-month Pro plan.
Flat monthly price	Agent 37: No. metered parts. The bill is cores plus memory plus disk, so it moves with the shape you choose.	Blaxel: No. per GB-second. The price follows the memory you allocate and the seconds it runs.	Boat: Yes. $26 a month for default	boxd: No. three meters. Cores, memory and disk are metered separately, so there is no single monthly price.	Cloudflare Sandbox: No. per 10 ms. The bill is a sum of active processor time, memory and disk.	Daytona: No. metered parts. The bill is cores plus memory plus disk per second.	E2B: No. per second parts. The bill is cores plus memory per second.	InstaBox: No. metered parts. The bill is cores plus memory per second, plus storage.	Lizard: Yes. $0.0324/h medium	Modal: No. request or use. The bill follows the higher of what you asked for and what you used.	Morph: No. one rate per unit. The price is a single rate per unit hour, not a fixed monthly price per machine.	Runtime: No. measured parts. The bill is measured processor time plus reserved memory plus storage.	Sandboxer: Yes. $26.28 a month default	Sprites: No. actual use. The bill follows the processor and memory actually used, so it varies with the work.	Tensorlake: No. metered parts. The bill is processor time plus memory plus disk plus storage.	Vercel Sandbox: No. active CPU plus memory. The bill is active processor time plus memory for as long as the sandbox runs.

YesWith a catchNoNot publishedHover or select a mark to see the catch.

What one personal agent costs

One always-on 2 vCPU / 4 GiB / 20 GiB machine that keeps its files. It waits for messages most of the time: about 6% CPU on average, with peaks near 100% when it browses or runs a command. Priced by the calculator, before the AI model. Every rate card

Provider	Cost	Detail
Agent 37	$10.60 a month	Per minute on the shape you reserve, with disk billed every hour until you delete the instance.
Lizard	$19.00 a month	A flat hourly price per size, idle time included, from a $19 plan that comes back as usage.
Boat	$20.00 a month	A flat hourly price per size, per second while the machine exists; the $20 plan is prepaid machine time.
InstaBox	$20.00 a month	Per second on the size you asked for, out of a monthly plan that is also a credit; storage bills in every state.
Runtime	$24.95 a month	Per second on measured CPU with a 50-millicore floor, reserved memory, and stored disk in decimal GB.
Sandboxer	$40.00 a month	A fixed multiplier per size, per second while running, out of a plan whose dollars come back as machine time.
Morph	$63.00 a month	Compute units per hour: the largest of vCPU, RAM ÷ 4 and disk ÷ 16, at $0.05 each.
Vercel Sandbox	$73.12 a month	Active CPU, excluding time spent waiting, plus provisioned memory for the whole session; persistent sandboxes keep their files as a snapshot between sessions. The catch: Sessions end after 24 hours, so an always-on machine has to be restarted by your own code.
Sprites	$77.61 a month	Measured CPU and memory while awake, hot storage while awake and cold storage for as long as data is kept.
Cloudflare Sandbox	$99.41 a month	Per 10 ms on the Workers Paid bill: CPU only while working, memory and disk for as long as the instance runs. The catch: A stopped instance loses its disk; files have to be backed up to R2 or a snapshot and restored.
boxd	$110.90 a month	Per second on three meters: vCPU on the machine's size while running, memory on what is actually resident, disk on bytes written in every state.
Daytona	$122.07 a month	Per second on reserved vCPU, memory and disk; stopped sandboxes bill disk only. The catch: 20 GiB of disk is over the 10 GiB limit.
Blaxel	$123.29 a month	Per second on allocated memory while active, CPU included; standby bills storage only.
Modal	$143.71 a month	Per second on the higher of requested and used CPU and memory, at 3× list for sandboxes; there is no stopped state. The catch: Sessions end after 24 hours, so an always-on machine has to be restarted by your own code. Modal sandboxes have no stopped state; keeping files needs a Volume or a snapshot.
Tensorlake	$250.00 a month	Per second on active CPU, allocated RAM and disk, drawn from prepaid credits or a $250 Pro plan; a suspended sandbox bills snapshot storage only.
E2B	$270.89 a month	Per second on allocated vCPU and memory while running; paused sandboxes cost nothing. The catch: Sessions end after 24 hours, so an always-on machine has to be restarted by your own code.

Questions to ask before you sign

Each one targets something the documentation does not answer

Does the meter measure the shape I reserved, or what the machine actually used?
Does the monthly fee return as usage, and what expires at the end of the month?
What is charged while stopped: compute, memory, storage, or nothing?
Which costs are missing from the pricing page — egress, snapshots, static IPs?
Is there a minimum billed duration or a one-minute increment, and how does it round?

Common questions

Answered from the capability checks; each links to the provider-by-provider detail and its sources

Which sandbox providers offer “billed per second”?: Usage is counted to the second rather than by the hour or month. Fully: Blaxel, Boat, Cloudflare Sandbox, Daytona, E2B, InstaBox, Lizard, Modal, Morph, Runtime, Sandboxer, Sprites, Tensorlake and boxd. With a catch: Vercel Sandbox. Not at all: Agent 37. See each provider's catch
Which sandbox providers offer “cPU billed only while working”?: An idle processor costs nothing or very little. Fully: Cloudflare Sandbox, Runtime, Sprites, Tensorlake and Vercel Sandbox. Not at all: Agent 37, Blaxel, Boat, Daytona, E2B, InstaBox, Lizard, Modal, Morph, Sandboxer and boxd. See each provider's catch
Which sandbox providers offer “paused costs only storage”?: A paused or stopped machine bills for its kept files only, not CPU or memory. Fully: Agent 37, Blaxel, Boat, Cloudflare Sandbox, Daytona, E2B, InstaBox, Lizard, Morph, Runtime, Sandboxer, Sprites, Tensorlake and Vercel Sandbox. With a catch: boxd. Not at all: Modal. See each provider's catch
Which sandbox providers offer “no monthly fee”?: Pay only for what you use, with no plan fee. Fully: Agent 37, Blaxel, Daytona, E2B, Modal, Morph, Runtime, Sprites, Tensorlake and boxd. With a catch: Vercel Sandbox. Not at all: Boat, Cloudflare Sandbox, InstaBox, Lizard and Sandboxer. See each provider's catch
Which sandbox providers offer “flat monthly price”?: A fixed price per month for a machine, so the bill is predictable. Fully: Boat, Lizard and Sandboxer. Not at all: Agent 37, Blaxel, Cloudflare Sandbox, Daytona, E2B, InstaBox, Modal, Morph, Runtime, Sprites, Tensorlake, Vercel Sandbox and boxd. See each provider's catch

Part of Money. Next: put two or three providers side by side.