Free tool
When does your free stack start charging you?
Pick what you are building on, describe the scale you expect, and see which limit runs out first. Most builders find this out from an invoice.
Limits checked 2026-09-02. Every allowance here is re-read from the provider's own pricing page daily. A number only changes if it appears word for word on their page, and anything that cannot be verified is held at its last confirmed value rather than guessed. Free tiers still move without notice: confirm on the provider's page before you make a decision that matters.
The scale you expect
At this scale
Everything here stays on its free plan at the scale you described. The traps below are the ones that catch people anyway.
Closest to flipping
Supabase is at 80% of its Egress allowance. You have about 1 GB of room left.
The traps that are not about scale
These are the free tier rules that catch people at any size, including at zero users.
Supabase
Free projects pause after seven days with no activity, and you are limited to two active projects.
Supabase pricingResend
There is also a 100 a day ceiling, so one launch blast can hit the wall while your monthly total still looks comfortable.
Resend pricingVercel
The Hobby plan is for non-commercial use only. The moment the site earns money their terms put you on Pro, whatever your traffic looks like.
Vercel pricingClerk
Clerk counts monthly retained users, not signups: a person only counts once they come back 24 hours or more after signing up. The free plan is called Hobby.
Clerk pricingQuestions people actually ask about these free tiers
How many users can the Supabase free tier handle?
50,000 monthly active users on paper. In practice the user cap is almost never what stops you: the free plan includes 5 GB of egress a month, and a busy app runs out of that long before it gets near 50,000 users. Put your real numbers into the tool above and it will tell you which of the two you hit first.
How much traffic can the Vercel free tier handle?
100 GB of fast data transfer a month on the Hobby plan. Traffic is rarely what ends a Hobby project, though. The commercial use rule below stops far more people than the bandwidth limit does.
Can I use the Vercel free tier for commercial use?
No. Hobby is for non-commercial use only. The moment the site earns money, Vercel's terms put you on Pro whatever your traffic looks like, so a side project with ten visitors and one paying customer is already over the line while a hobby project with 90 GB of traffic is fine.
Does the Gemini API have a free tier?
Yes. Google publishes a free tier with per-model caps on requests per minute and requests per day. We deliberately do not restate those numbers here: they are split across model and tier tabs that we cannot read reliably enough to keep honest, and they change often. Read them on Google's own rate limits page. One figure that is stable and worth knowing: Search grounding is 1,500 requests a day free, then $35 per 1,000 grounded prompts.
Does the OpenAI or Claude API have a free tier?
Not an ongoing one. Aside from any introductory credits on a new account, you pay per token from the first call. That is the case the AI Cost Calculator is built for: work out what one user costs you a month before you promise anyone unlimited anything.
What this assumes
One project per service, on the standard free plan, paying list price when you cross. It compares your expected scale against each published allowance and flags the one that runs out first. It does not model usage-based overage billing, annual discounts, startup credits, or the free allowance included inside a paid plan. The daily check verifies the allowances; plan names, prices and the traps below are maintained by hand.
Crossing into paid is the cheap problem
The expensive one is a database anyone can read, or an API key shipped in your JavaScript. Both are free to have and free to find. Our scan checks for them in seconds.
Check my app