Credit card traps in AI compute free credits

Short versionDecision ledger

Rent	When	Example
Check the default plan	Signup can land you on a paid plan. Koyeb defaults new accounts to the $29 per month Pro plan and charges prorated fees until you downgrade to Starter.	Koyeb
Know what a card changes	Adding a card ends the Fly.io trial and starts billing. Linking a card on Deno Deploy unlocks the full free limits. Same act, opposite deals.	Fly.io
Know what happens at $0	An empty balance can mean stopped machines, destroyed data, a locked account, or an automatic bill. It is never nothing.	Vast.ai

Seven trap patterns and one benign pattern, drawn from every tracked offer, checked against official pages.Checked 2026-08-21

Do I need a credit card for the free tier, and what can it cost me if I add one? Across the 55 free credit and free tier offers tracked on this site, 24 officially require a card or payment method, 8 officially do not, and 23 do not state it either way. The card itself is rarely the trap. The trap is what surrounds it: a signup flow that defaults to a paid plan, a trial that starts billing on its own, a deposit circulated by roundup posts as a free credit, a credit that cannot pay for the product you came for, and platforms that stop machines and delete data the moment a balance touches zero. This page catalogs each pattern, quotes the official wording verbatim, and links the dated entry for every provider named.

Method: official pages only, checked 2026-08-21, fail closed

Every claim on this page comes from official provider pages: pricing pages, billing and trial docs, FAQs, and legal terms. Most were checked on 2026-08-21; a few entries carry 2026-08-20, and each linked entry shows its own date. No Reddit threads, no coupon blogs, no third-party roundups. Where an official page does not state something, the entries record it as not stated officially rather than guessing, and figures that circulate only off-platform are treated as stale and flagged as corrections in the entries.

The pipeline behind this site reads each official page at least twice: once while compiling the category research notes, and again while writing the published entry, both against the live page. Where those two reads agree, that is stated below as a page read twice; where two official pages from the same provider disagree with each other, both are quoted rather than picking a winner. One more discipline matters on a page about money: I have not personally triggered any of these charges. This is a catalog of documented terms, not billing experiences. The limitations section spells that out.

Trap 1: the default plan is not the free plan

One provider in the set charges you for a plan you never chose unless you act: Koyeb. Signing up puts a new account on the Pro trial track, and Koyeb charges prorated fees for the $29 per month Pro plan until you downgrade to the free Starter plan. The free tier people come for, one small web Service plus one small PostgreSQL, lives on Starter. So a reader who creates an account, deploys the free service, and walks away is billed for Pro anyway. This is the single worst trap in the 55, because the charge requires no usage at all; the default plan does the work.

Three official details make it stickier. The pricing FAQ says “We require a credit card to prevent fraud and abuse,” and the official word there is credit card, not payment method. Koyeb places a $29 pre-authorization hold, and account validation can take up to 3 business days. And there is no spending-limits feature to act as a backstop. The $5.50 monthly credit that older lists still cite was discontinued on 1 February 2024, per the same FAQ. The default-to-Pro rule was recorded independently in this project’s research notes and in the published entry, which means the official FAQ was read twice on the same day; the wording did not change between reads. Full numbers on the dated page: Koyeb free tier.

The defense is one action: downgrade to Starter the day you sign up, before you deploy anything.

Trap 2: the trial that ends in a bill, a closure, or a freeze

Trials in this set end three different ways, and only one of them is a bill.

OVHcloud is the bill. Its US$200 Public Cloud trial runs one month from the creation of your first Public Cloud project, a valid payment method is required before the trial starts, and once the credit is consumed, charges continue on that payment method automatically. If you want a hard stop at $0, you must delete your resources yourself before the credit runs out. The clock starts at project creation, not account creation, so the second sharp edge is creating the project before you are ready to use the month. Details: OVHcloud free credits.

AWS is the opposite direction: account death instead of billing. The current Free Tier gives “up to $200 in credits” ($100 at signup, up to $100 more earned by exploring services) over a free plan that ends at the earlier of 6 months or credit exhaustion. The account is then closed unless you upgrade to the Paid plan, with a 90 day window to retain your data. On cards, the FAQ wording is “AWS requires a valid payment method to verify your identity,” and you are not charged until you upgrade. So the failure mode of neglect is not a surprise invoice; it is a dead account and, past the window, lost data. A further conversion hides in organizational tooling: joining an AWS Organization or Control Tower expires the credits immediately and auto-upgrades the account to Paid. Details: AWS Free Tier credits.

Azure sits between: the freeze. The free account gives a “$200 credit to use on Azure services within 30 days.” When the 30 days or the credit run out, you must upgrade to pay-as-you-go to keep resources running; otherwise the subscription is disabled. Nothing bills by itself, but nothing keeps running either, and unused credit does not carry over past day 30. Details: Azure free credits.

Before starting any trial, ask which of the three endings it has: a bill (OVHcloud), a closure (AWS), or a freeze (Azure). The answer decides what forgetting the account costs you.

Trap 3: adding a card changes the deal you are on

The clearest contrast pair in the catalog is Fly.io against Deno Deploy. The physical act is identical, typing a card number into a billing page. The consequences are opposite.

On Fly.io, the trial is “2 hours of machine runtime or 7 days of access, whichever comes first,” no card needed to start. Adding a payment card ends the trial early and billing starts from that point. The card is the off switch. If you are still evaluating, the correct move is to not add a card until you have decided; there is no partial state where the card sits idle and the trial continues. This rule appears in this project’s research notes and the published entry from the same official trial page, read twice on 2026-08-21 with the same wording both times. Details: Fly.io free trial.

On Deno Deploy, the card unlocks the free tier instead of ending it. The Free plan is $0 per month with 1 million requests, 20 GB egress, and 15 CPU hours monthly, but organizations get “restricted Free plan limits until they verify their organization by linking a credit card.” No official page says the card is charged on the free plan; it is verification. This is the benign version of the same mechanism, and it is why “does adding a card cost me anything” has no general answer. Details: Deno Deploy free tier.

The pair is worth internalizing because most people carry one mental model, usually the benign one, across every platform. The Fly.io model exists, so verify per platform before you type the number.

Trap 4: a card is required before you can touch the credit at all

Some free credits and free tiers are unreachable without a payment method, which converts “free” into “free after you hand over a billing instrument.”

Modal is the plainest statement of the pattern. Its Starter plan includes $30 per month of credits, labeled “included compute” on the pricing page, on a $0 base plan, a genuine recurring allowance. But the billing docs state that “you must have a payment method on file in order to use Modal.” There is no officially described way to consume the monthly credits without one. The official word is “payment method,” not “credit card,” a distinction Modal’s docs keep and this site mirrors. Details: Modal free tier.

Azure specifies the instrument. Signup requires a credit card or debit card, non-prepaid, with a $1 temporary authorization, not a charge. In Hong Kong and Brazil, only credit cards work. So the $200 credit is gated on a real, non-prepaid card, and in two markets specifically on a credit card. Details: Azure free credits.

Crusoe is stricter still. Account creation requires a “valid, non-prepaid credit card,” per its docs, before you can reach its $5 serverless credit. The official wording really is credit card, and it excludes prepaid cards explicitly. Five dollars of credit behind a mandatory non-prepaid credit card is a legitimate offer, but it is not what most people picture when they read free credits. Details: Crusoe free credits.

Two mitigating patterns exist inside this trap. First, the temporary authorization: Azure documents $1, Google Cloud documents a hold of “a value between $0.00 and $1.00 USD” that is a hold, not a charge, and Scaleway documents a reimbursed 1 euro authorization. A small pending transaction after signup is usually this, not billing. Second, the wording distinction between payment method and credit card is load-bearing: where a provider says payment method, alternatives to a card may exist; where it says credit card, non-prepaid, they do not. The entries quote whichever words the provider uses.

Trap 5: the deposit dressed up as a credit

Three GPU marketplaces are routinely listed in roundup posts as offering free credits when the money involved is entirely yours.

RunPod: the circulating claim is a $10 free credit. The official billing docs say RunPod is prepaid and you can “start with as little as $10.” That is a deposit floor, not a grant. The real referral bonus that likely seeded the myth requires loading at least $10 of your own money first, plus Google SSO and other conditions, and about 96 percent of non-EU users get $10 or less from it. Details: RunPod free credits.

Vast.ai: the circulating claim is $5 free. The site’s own “Get Started for $5” is a minimum deposit, and the docs state “The minimum deposit amount on Vast.ai is $5.” Both the research notes and the published entry recorded that sentence from the docs on 2026-08-21, so the page was read twice in this project’s pipeline with the same result. Details: Vast.ai free credits.

TensorDock: the circulating claims are a $1 promo code, $5 in testing credit, and $15 bundles. None of those appear on TensorDock’s official pages as of 2026-08-21. What the official site says is “Start with just $5,” again a deposit. Details: TensorDock free credits.

The test is simple and works everywhere: if the dollars leave your bank account, it is a deposit, whatever a third-party post calls it. Of the 55 offers tracked, 17 are filed as no free credit, and this deposit-as-gift confusion is the single most common reason a provider ends up in that bucket with a correction attached.

Trap 6: what happens at $0 is the real terms of the deal

Prepaid platforms do not bill you past zero. What they do instead is documented, and it is often worse than a small bill.

RunPod stops pods when your balance hits $0, and if the pod had no network volume, the data is gone. The docs also require at least one hour of credits at the pod’s rate to deploy at all, and stopped pods still bill disk at $0.20 per GB per month. Details: RunPod free credits.

Vast.ai stops instances at $0 while storage keeps billing, and if there is no card on file to cover it, instances and data can be destroyed. The docs also say plainly, “Instances showing in your account are never free.” An empty Vast.ai account is not a paused account. Details: Vast.ai free credits.

fal.ai locks the account when the balance falls below a threshold. No destruction is documented, but the account-level lock means a $0 balance takes your API access with it. Details: fal.ai free credits.

Render’s free tier does not bill at all without a payment method on file; services suspend at quota instead. The destruction here is on a clock rather than a balance: free Postgres expires 30 days after creation, with a 14 day grace period before deletion. A free database that deletes itself after about six weeks belongs in any inventory of ways free costs you something. Details: Render free tier.

Railway deletes trial volumes 30 days after the trial credit expires. The $5, 30 day trial needs no card, and the later Free plan gives $1 of monthly usage credit, but a database left on a lapsed trial does not survive the quarter. Details: Railway free trial.

The pattern to extract: on prepaid platforms, the price of free is that the floor is not a pause. Before parking anything you care about on a free balance, find the provider’s zero-balance paragraph and read it as the real terms of the deal.

Trap 7: the credit that cannot pay for what you came for

Scope restrictions are the quiet trap: the credit is real, the dollar amount is real, and none of it applies to the usage you signed up to try. Surprise spend follows when the real usage bills alongside an untouched credit.

Daytona advertises “$200 in free compute included” with no credit card required, and lists GPU sandboxes at per-hour rates, H100 at $2.27 per hour among them. But the billing docs state the free credit balance is “not available for GPU sandboxes.” The $200 cannot buy a single GPU minute; it pays for CPU sandbox compute only. Both the research notes and the published entry recorded that exclusion from the billing docs on 2026-08-21, two reads of the same page, same wording. If you add a card later and start a GPU sandbox, that usage bills for real while the $200 sits there. Details: Daytona $200 credit.

Northflank runs the same gate in a different shape. The Developer Sandbox plan is free, but there is no cash credit, every user must add a payment method to create resources, and GPU workloads require a credit purchase of $50 or more to unlock access. The docs add that GPU services stop immediately when credits run out. The cheapest possible Northflank GPU is $50 of your own prepaid money. Details: Northflank free credits.

Novita’s registration page offers “Get $100 in Sandbox credits, valid for 90 days. No credit card required.” The scope is in the sentence: Sandbox credits. They meter CPU and RAM inside the Sandbox code-execution product, not GPU instances and not the model API, and Novita is best known for GPUs and inference. Reading “$100 free” as free GPU time or free LLM tokens is exactly the mistake the wording invites. Details: Novita Sandbox $100.

The question that defuses this trap: what specifically does this credit meter? If the pricing page lists the product you want as a separate line item, confirm the credit touches that line before you count the dollars.

The benign end: no-card offers that behave

Calibration matters. Not every free offer converts, and the well-behaved ones share a shape: no card at signup, and limits that fail toward a pause or a block instead of a charge. Of the 55 offers, 8 officially require no card; four examples define the pattern.

Daytona: “$200 in free compute included,” “no credit card required,” per its pricing page. The GPU scope exclusion above still applies, but with no card on file the account cannot convert into a bill. Daytona $200 credit.

Novita: “$100 in Sandbox credits, valid for 90 days. No credit card required.” Scoped, but honest about it, and the 90 day expiry is stated up front. Novita Sandbox $100.

E2B: the Hobby plan is $0 per month with a one-time $100 usage credit, and the pricing page’s signup button says no credit card is required. The documented end state is a block, not a bill: “What happens when I run out of credits? Your account will be blocked. Add a payment method to continue using E2B.” That is the correct failure direction. E2B Hobby $100.

Neon: the Free plan has, in its own words, “no time limits and no credit card required.” Run out of monthly compute hours and compute suspends until the next period; exceed the 0.5 GB storage cap and writes fail. Annoying, safe, and free of billing surprises. Neon free tier.

The shared property is fail-closed billing: when something runs out, the platform stops doing work instead of starting to charge. That property is worth more than the dollar figure on the credit.

A third shape sits between the traps and this group: offers whose official pages do not state a card requirement either way. That bucket holds 23 of the tracked entries. Two of them are worth naming here because both still fail toward a stop. Cloudflare Workers stops the over-quota operation until its daily limits reset and bills nothing on the free plan. A free Supabase project is paused after a period of inactivity and has to be restored before it serves again. Unstated is not the same as no card required, so read the dated entry before filing either one alongside Daytona and E2B.

Verdict

Choose a no-card offer if you are experimenting, might forget the account, or cannot absorb a surprise charge: Daytona, Novita, E2B, and Neon all start without a card and fail toward a stop, not a bill.

Accept a card-on-file offer if the credit is worth the exposure and you will do the safety work the same day: on Koyeb that means downgrading to Starter immediately; on OVHcloud it means a calendar reminder to delete resources before the US$200 runs out; on Azure and AWS it means deciding before the deadline whether the account upgrades or dies.

Never assume adding a card is neutral. It ends the trial on Fly.io, unlocks the free limits on Deno Deploy, and starts real GPU billing next to an unusable credit on Daytona. Never assume a $0 balance is a pause: on RunPod and Vast.ai it is documented as stopped machines and destroyable data. And never take a dollar figure from a roundup post: the $10, $5, and $15 “credits” at RunPod, Vast.ai, and TensorDock are deposits or absent from official pages entirely.

Limitations

I have not personally triggered any of these charges. Nobody on this project has paid Koyeb’s prorated Pro fee, ridden OVHcloud past its US$200, or watched Vast.ai destroy an instance at $0. Every entry cited here carries “Not tested yet” in its what-I-have-done section, and this page inherits that discipline: it documents terms as officially written, not billing experiences. Terms can also change after the check date; each linked entry shows when its numbers were last verified, and the sources list below points at the exact official pages so you can re-read them yourself. Where a provider’s own pages disagree, the entries quote both sides, the way Civo’s legal terms say 31 calendar days while its marketing says a full month, and Google Cloud’s terms say 3 months while its docs say 90 days. Finally, this catalog covers the 55 offers tracked on the credits index; it is a census of that set, not of the whole market.

If you are choosing where to spend a free credit in the first place, start with how to choose between a VPS, GPU cloud, serverless, or a sandbox. Every offer named here has a dated entry with the official wording, the sources, and the check date on the credits index.