Money
“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.
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.
The claim on the left, the provider's own words on the right
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.
InstaBox's free plan gives one 4 vCPU / 8 GiB machine, two templates, a fixed 30-minute idle pause and an 8-hour maximum continuous run. 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.
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.
The details that decide the answer in practice
Whether a card is required, and whether a paid plan starts automatically.
Whether the allowance is money, hours or a machine, and at which size.
Whether the free tier can stay up, or is capped by idle pause and session limits.
Whether a second trial is available on the same account or card.
What happens when a credit runs out: block, stop, or charge.
Docs read 28 October 2026
| Provider | Does it? | What that means |
|---|---|---|
| Agent 37 | 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. |
“Add a card from the billing page (nothing is charged) and your workspace gets a one-time $5 credit” | ||
| Blaxel | 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. |
“Up to $200 in free credits” | ||
| Boat | 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. |
“There is no free tier. Your first plan starts with a free 7-day trial, and checkout asks for a card.” | ||
| boxd | 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. |
“€30 of credits when you add a payment method. Nothing is charged when you add the card” | ||
| E2B | 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. |
“One-time $100 in usage credits.” | ||
| InstaBox | Yes | A real free plan: one 4 vCPU / 8 GiB machine, 20 GiB fixed disk, five snapshots, 100 GiB egress, an 8-hour run cap and two templates. It never converts. |
“1 machine, 4 vCPU / 8 GiB” | ||
| Lizard | 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. |
“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.” | ||
| Morph | 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. |
“Once you have your invite, our $0/month Developer Plan provides 300 free compute hours per month” | ||
| Runtime | 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. |
“An account that has never paid gets the machine time once, across its first 30 days.” | ||
| Sandboxer | 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. |
“7 days, 25 hours of machine time, up to 2 sandboxes at once on the small and default sizes” | ||
| Sprites | 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. |
“Each user can grant one $30 trial credit, and each org can receive at most one.” | ||
| Vercel Sandbox | 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. |
“Unlock the full potential of Vercel Pro during your 14-day trial with $20 in credits.” | ||
Part of Money. Next: put two or three providers side by side.