Which sandbox providers offer “ongoing free tier”?

Something keeps working for free every month, not only at the start. Fully: InstaBox, Runtime and Tensorlake. With a catch: Modal, Morph and Vercel Sandbox. Not at all: Agent 37, Blaxel, Boat, Cloudflare Sandbox, Daytona, E2B, Lizard, Sandboxer, Sprites and boxd.

Which sandbox providers offer “free starting credit”?

Credit to spend when you sign up. Fully: Agent 37, Blaxel, Daytona, E2B, Modal, Sprites and boxd. With a catch: Lizard, Morph, Runtime and Vercel Sandbox. Not at all: Boat, Cloudflare Sandbox, InstaBox, Sandboxer and Tensorlake.

Which sandbox providers offer “try without a card”?

You can start without entering a payment card. Fully: Blaxel, Daytona, E2B, InstaBox, Runtime, Tensorlake and boxd. Not at all: Agent 37, Boat, Cloudflare Sandbox, Lizard, Modal and Sandboxer.

Trials and free tiers

The idea

A time-limited trial gives access for a fixed number of days and then either charges you or stops. A one-off credit is money added to a prepaid balance once, spent at normal rates. A free plan is a permanent tier with hard caps. A recurring allowance is free usage that returns every month.

The card is not the dividing line. A trial with a card usually converts when its clock runs out. A credit with a card is spent and then stops. A free plan or allowance with no card never charges, but caps size and runtime instead. Read the ending as three questions: is the card charged, does a paid plan start, and does the allowance stop?

The unit matters too. Five dollars is about 100 hours of Agent 37's entry shape, and less than an hour of boxd's largest machine. Twenty-five hours at Boat is capped by a mandatory two-hour auto-stop, so it cannot test an always-on agent.

Where providers split

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

The one that converts itself

Sandboxer's seven-day trial becomes $20 a month on day eight. Boat's trial ends by charging the plan chosen at checkout. Lizard's trial ends and you either subscribe to Pro at $19 or stop creating things. Those are the three that end at a paid plan.

Everything else is spent, not converted: E2B's $100 credit, boxd's $30, Agent 37's $5, Blaxel's credits, Sprites' $30, Morph's disputed 300 hours, Runtime's allowance and InstaBox's free plan.

The free plans have hard caps

InstaBox's free plan gives one 4 vCPU / 8 GiB machine, two templates, and a fixed 30-minute idle pause. Runtime's free usage caps at 2 vCPU / 4 GiB / 10 GiB, four sandboxes at once and 50 created a day. Vercel's Hobby plan is non-commercial and pauses sandbox creation when its quotas run out.

Those caps are the product decision. A free plan that cannot stay up is not a substitute for a cheap paid one.

Credits run out silently

A credit is spent at the same rates as paid usage, so its value depends on the shape and the provider. When E2B's credit runs out without a payment method, every project in the workspace is blocked shortly afterwards. boxd's credit is drawn from a prepaid balance; there is no plan to fall back on.

A credit is not a trial: it does not expire on a date, it expires when the money does.

One worked case

The same job at every provider, from the documented defaults

A week of testing, then a small agent that stays up

You want seven days to test, then one small always-available agent. The trial has to answer three questions: is a card needed, does a paid plan start by itself, and can the free machine stay up?

Day 1
You sign up. A card may be required before the first machine exists.
Day 7
The trial ends. It either converts to a paid plan, stops, or keeps spending a credit.
Day 8
The agent should still answer. A free tier capped by an idle pause and an eight-hour run limit does not.

Three trials end by starting a paid plan, the rest are spent. The cap that matters is not the credit but the idle pause and the continuous-runtime limit, because those decide whether the free machine can stay up.

What each provider does

Agent 37: A one-off $5 Cloud credit after adding a card, plus a managed-hosting free plan with no card; the credit is not granted to workspaces made through the signup API.
Blaxel: Up to $200 in promotional credits advertised; the actual grant, expiry and card requirement are not published.
Boat: A seven-day trial with a card: 25 hours in total, two sandboxes, small and default sizes, and a mandatory two-hour auto-stop.
boxd: A one-off €30/$30 credit after adding a payment method; without one, an organisation is capped at two machines with no published allowance.
Cloudflare Sandbox: There is no free sandbox: the $5 Workers Paid plan is required, and its included container usage is worth about $0.73.
Daytona: The trial is $200 of compute with no card and no published expiry; GPU sandboxes cannot spend it.
E2B: A one-time $100 credit with no card; when it runs out without a payment method, every project is blocked shortly afterwards.
InstaBox: A real free plan: one 4 vCPU / 8 GiB machine, 20 GiB disk, five snapshots and a fixed 30-minute idle pause, and it never converts.
Lizard: Seven days with $5 of usage, a card required, Small machines only and US regions only.
Modal: Starter gives $30 of compute a month, but a payment method is required before anything runs.
Morph: Signup docs promise 300 free compute hours a month; the pricing page lists 0 MCUs and says to purchase them.
Runtime: Recurring free usage with no card: 100 hours of a 1 GB machine with hard caps on size and concurrency.
Sandboxer: Seven days with 25 hours of machine time and a card up front; it becomes $20 a month on day eight.
Sprites: A one-time $30 trial credit per user and per organisation; credits cannot pay a subscription fee.
Vercel Sandbox: Hobby quotas restricted to non-commercial use, or a 14-day Pro trial with $20 in credits.
Tensorlake: A free account runs one 1 vCPU / 1 GB sandbox for up to two hours at a time, with no card, and nothing converts on its own.

What to watch for

The details that decide the answer in practice

01
Whether a card is required, and whether a paid plan starts automatically.
02
Whether the allowance is money, hours or a machine, and at which size.
03
Whether the free tier can stay up, or is capped by idle pause and session limits.
04
Whether a second trial is available on the same account or card.
05
What happens when a credit runs out: block, stop, or charge.

Compare all 16

Docs read 28 October 2026

“Free trial” covers four different offers: a time-limited trial that converts, a one-off credit, a free plan that never charges, and a recurring allowance. They differ in what you get and what happens on day eight.
Provider	What you get, and what ends it	Does it?	What that means
Agent 37	$5 one-off	Partly	A one-off $5 Cloud credit after adding a card, and a managed-hosting free plan with no card. The credit is not granted to workspaces created through the signup API.Agent 37 docs: Pricing — free starter credit and what it covers ↗ Agent 37's own wordsdocs-confirmed “Add a card from the billing page (nothing is charged) and your workspace gets a one-time $5 credit” Agent 37docs-confirmed
Blaxel	Up to $200 credits	Partly	Up to $200 in promotional credits advertised on pay-as-you-go. The actual grant, expiry and card requirement are not published. Quota tiers are wallet top-ups, not fees.Blaxel docs: Pricing ↗ Blaxel's own wordspricing-page “Up to $200 in free credits” Blaxelpricing-page
Boat	25 h trial	Partly	A seven-day trial with a card and no free tier: 25 hours in total, two sandboxes at once, small and default sizes, a mandatory two-hour auto-stop and no new saved snapshots.Boat docs: Free trial ↗ Boat's own wordsdocs-confirmed “25 hours in total, all sandboxes together” Boatdocs-confirmed
boxd	$30 one-off	Partly	A one-off €30/$30 credit after adding a payment method. No free plan; an organisation without a payment method is capped at two machines, with no published allowance.boxd docs: Pricing: what you get for free ↗ boxd's own wordspricing-page “€30 of credits when you add a payment method. Nothing is charged when you add the card” boxdpricing-page
Cloudflare Sandbox	None$5 plan	No	No free tier for containers; the Free column is N/A. Workers Paid has a $5 monthly minimum and includes 25 GiB-hours, 375 vCPU-minutes and 200 GB-hours of container usage.Cloudflare Sandbox docs: Workers plans and pricing ↗ Cloudflare Sandbox's own wordsdocs-confirmed “Available on Workers Paid plan” Cloudflare Sandboxdocs-confirmed
Daytona	$200 credit, no card	Yes	A $200 free compute credit with no card, and Tier 1 access by email verification. The credit is not available for GPU sandboxes; its expiry is not published.Daytona docs: Limits: tiers and access requirements ↗ Daytona's own wordspricing-page “$200 in free compute included” Daytonapricing-page
E2B	$100 one-off	Yes	A one-time $100 usage credit on Hobby, with no card to start. When it runs out without a payment method, every project in the workspace is blocked shortly afterwards.E2B docs: Pricing (Hobby, Pro, Enterprise) ↗ E2B's own wordspricing-page “One-time $100 in usage credits.” E2Bpricing-page
InstaBox	Free plan, 1 machine	Yes	A real free plan: one 4 vCPU / 8 GiB machine, 20 GiB fixed disk, five snapshots, 100 GiB egress, a fixed 30-minute idle pause and two templates. It never converts.InstaBox docs: Pricing — Free plan allowances ↗ InstaBox's own wordspricing-page “1 machine, 4 vCPU / 8 GiB” InstaBoxpricing-page
Lizard	7 days / $5	Partly	A seven-day trial with $5 of usage, a card required, Small machines only, US regions only and up to five at once. One trial per account and per card.Lizard docs: Billing — trial terms ↗ Lizard's own wordsdocs-confirmed “Pro starts with a 7-day trial that includes $5 of usage. You add a card to start it; Apple Pay works too. Nothing is charged when the trial starts.” Lizarddocs-confirmed
Modal	$30/month credits	Partly	Starter is $0 plus compute with $30 a month of credits; Team is $250 plus compute with $100. A payment method is required to use Modal.Modal docs: Pricing plans (Starter monthly credit) ↗ Modal's own wordspricing-page “$30 / month free credits” Modalpricing-page
Morph	300 h/month claimed	Partly	Signup docs promise 300 free compute hours a month on the $0 Developer plan; the pricing page lists 0 MCUs and says to purchase MCUs. An invite is mentioned.Morph docs: Plans ↗ Morph's own wordsdocs-confirmed “Once you have your invite, our $0/month Developer Plan provides 300 free compute hours per month” Morphdocs-confirmed
Runtime	100 h free, no card	Yes	Recurring free usage with no card: 100 hours of a 1 GB machine, memory and CPU allowances, and hard caps on size and concurrency. Accounts that never pay get it once across 30 days.Runtime docs: Free usage ↗ Runtime's own wordspricing-page “100 free hours of a 1 GB machine” Runtimepricing-page
Sandboxer	7 days / 25 h, then a plan	Partly	A seven-day trial with 25 hours of machine time, two sandboxes, small and default sizes, and a card up front. It becomes $20 a month on day eight.Sandboxer docs: Pricing (trial) ↗ Sandboxer's own wordspricing-page “7 days, 25 hours of machine time, up to 2 sandboxes at once on the small and default sizes” Sandboxerpricing-page
Sprites	$30 one-off	Partly	A one-time $30 trial credit per user and per organisation. Credits cannot pay a subscription fee. Card requirement and expiry are not published.Sprites docs: Sprites FAQ — trial credits ↗ Sprites's own wordsdocs-confirmed “Each user can grant one $30 trial credit, and each org can receive at most one.” Spritesdocs-confirmed
Vercel Sandbox	Hobby quotas14-day Pro	Partly	Hobby has included quotas but is restricted to non-commercial use, and pauses sandbox creation when quotas run out. Pro has a 14-day trial with $20 in credits.Vercel Sandbox docs: Hobby plan ↗ Vercel Sandbox's own wordsdocs-confirmed “Unlock the full potential of Vercel Pro during your 14-day trial with $20 in credits.” Vercel Sandboxdocs-confirmed
Tensorlake	Free forever, 1 sandbox	Yes	Free is $0 forever with no credit card: 1 concurrent sandbox, 1 vCPU / 1 GB / 10 GB, 2-hour sessions, unmetered sessions and SOC 2. Usage Credits begin with a $5 pack you choose; unused credits are kept rather than refunded and come back if you return to the plan.Tensorlake docs: Pricing — plans, the free tier and credit packs ↗ Tensorlake's own wordspricing-page “You can start on our Free tier and run 1 sandbox at a time — no credit card required.” Tensorlakepricing-page

The specific capabilities

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

Trials and free tiers: capabilities by provider
Capability	Agent 37	Blaxel	Boat	boxd	Cloudflare Sandbox	Daytona	E2B	InstaBox	Lizard	Modal	Morph	Runtime	Sandboxer	Sprites	Tensorlake	Vercel Sandbox
Ongoing free tier	Agent 37: No. one-off $5 credit. There is no monthly free allowance; the only free usage is a one-off $5 credit.	Blaxel: No. one-off credits. Free usage is a one-off promotional credit, not something that returns each month.	Boat: No. trial only. There is no free tier; the only free usage is a seven-day trial that needs a card.	boxd: No. one-off credit. Free usage is a one-off credit that needs a card, not a monthly allowance.	Cloudflare Sandbox: No. none. Sandboxes only run on the paid Workers plan.	Daytona: No. one-off $200. The $200 is a one-time credit, not something that returns every month.	E2B: No. one-off $100. The $100 is a one-time credit, not a monthly allowance.	InstaBox: Yes. 1 machine, 4 cores / 8 GiB	Lizard: No. 7-day trial. There is no free tier, only a seven-day trial that needs a card.	Modal: With a catch. $30 a month, card needed. Thirty dollars of free compute returns each month, but a payment method must be on file before anything runs.	Morph: With a catch. 300 hours claimed. The signup page promises 300 free hours a month, but the pricing page shows no free compute and asks you to buy units.	Runtime: Yes. 100 hours a month	Sandboxer: No. trial only. There is no free tier, only a seven-day trial that becomes a $20 plan.	Sprites: No. one-off $30. Free usage is a one-time $30 credit, not a monthly allowance.	Tensorlake: Yes. 1 machine, 1 core / 1 GB	Vercel Sandbox: With a catch. Hobby, personal use only. The free Hobby plan is limited to personal projects and stops creating sandboxes when its allowance runs out.
Free starting credit	Agent 37: Yes. $5	Blaxel: Yes. up to $200	Boat: No. none. There is no credit; the free offer is 25 hours of machine time inside a trial.	boxd: Yes. €30	Cloudflare Sandbox: No. none. There is no starting credit; you pay the $5 monthly plan from the start.	Daytona: Yes. $200	E2B: Yes. $100	InstaBox: No. none. There is no starting credit; the free plan is a machine, and paid plans include usage equal to their fee.	Lizard: With a catch. $5 inside a trial. The $5 comes only as part of a seven-day trial and needs a card.	Modal: Yes. $30 a month	Morph: With a catch. 300 hours claimed. One page promises 300 free hours a month, while the pricing page lists no free units.	Runtime: With a catch. matched credit. There is no plain signup credit; whatever you add in your first 30 days is doubled, up to $1,000.	Sandboxer: No. none. There is no credit; the trial is 25 hours of machine time that becomes a paid plan.	Sprites: Yes. $30	Tensorlake: No. none. There is no starting credit; the free plan is a small machine and credit is bought in packs.	Vercel Sandbox: With a catch. $20 in a 14-day trial. The credit is part of a 14-day Pro trial, not a standing signup credit.
Try without a card	Agent 37: No. card for the credit. A card is needed to get the credit that makes the first machine runnable.	Blaxel: Yes. no card	Boat: No. card at checkout. Checkout asks for a card before the trial starts.	boxd: Yes. 2 machines without one	Cloudflare Sandbox: No. paid plan first. You need a paid Workers plan, which means a payment method, before a sandbox can run.	Daytona: Yes. no card	E2B: Yes. no card	InstaBox: Yes. free plan	Lizard: No. card for the trial. You add a card to start the trial, though nothing is charged at that point.	Modal: No. card required. A payment method must be on file before you can use Modal at all.	Morph: Not published	Runtime: Yes. no card	Sandboxer: No. card for the trial. The trial needs a card up front and becomes a paid plan after seven days.	Sprites: Not published	Tensorlake: Yes. free plan, no card	Vercel Sandbox: Not published

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

What you get without paying

Plans with no monthly fee, and the usage they include, from each rate card. Every rate card

Provider	Cost	Detail
Agent 37	Pay as you go	Cloud API wallet
Blaxel	Pay as you go	Pay as you go
Boat	No free plan	Cheapest plan $20.00 a month.
boxd	Pay as you go	Prepaid credit
Cloudflare Sandbox	No free plan	Cheapest plan $5.00 a month.
Daytona	Pay as you go	Pay as you go
E2B	Pay as you go	Hobby: Hobby starts with a one-time $100 credit, not subtracted here.
InstaBox	No free plan	Cheapest plan $20.00 a month.
Lizard	No free plan	Cheapest plan $19.00 a month.
Modal	$30.00 of usage	Starter
Morph	Pay as you go	Developer
Runtime	Pay as you go	Prepaid credit
Sandboxer	No free plan	Cheapest plan $20.00 a month.
Sprites	Pay as you go	Pay as you go
Tensorlake	Pay as you go; Pay as you go	Usage Credits: Prepaid packs of $5, $10 or $20 (500–2,000 CU; 1 CU = $0.01). At a zero balance Tensorlake stops running sandboxes rather than billing an overage. Free: One sandbox at a time, no card, 2-hour sessions.
Vercel Sandbox	Pay as you go	Hobby

Questions to ask before you sign

Each one targets something the documentation does not answer

Is a card required, and does a paid plan start automatically when the trial ends?
Is the allowance money, hours or a machine — and at which size?
Can the free tier stay up, or is it capped by idle pause and session limits?
Is a second trial available on the same account or card?
What happens when the credit runs out: block, stop, or charge?

Common questions

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

Which sandbox providers offer “ongoing free tier”?: Something keeps working for free every month, not only at the start. Fully: InstaBox, Runtime and Tensorlake. With a catch: Modal, Morph and Vercel Sandbox. Not at all: Agent 37, Blaxel, Boat, Cloudflare Sandbox, Daytona, E2B, Lizard, Sandboxer, Sprites and boxd. See each provider's catch
Which sandbox providers offer “free starting credit”?: Credit to spend when you sign up. Fully: Agent 37, Blaxel, Daytona, E2B, Modal, Sprites and boxd. With a catch: Lizard, Morph, Runtime and Vercel Sandbox. Not at all: Boat, Cloudflare Sandbox, InstaBox, Sandboxer and Tensorlake. See each provider's catch
Which sandbox providers offer “try without a card”?: You can start without entering a payment card. Fully: Blaxel, Daytona, E2B, InstaBox, Runtime, Tensorlake and boxd. Not at all: Agent 37, Boat, Cloudflare Sandbox, Lizard, Modal and Sandboxer. See each provider's catch

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