--- title: Top 5 Free APIs for Side Projects That Actually Matter url: https://apyhub.com/blog/best-free-apis-2026 author: Nikolas Dimitroulakis published: 2026-06-23T00:00:00Z tags: [engineering] --- # Top 5 Free APIs for Side Projects That Actually Matter # Top 5 Free APIs for Side Projects That Actually Matter A good free API for a side project is one with a permanent free tier (not a 60-day trial), no credit card to start, and enough headroom to ship something real before you ever pay. This list is five of those — Supabase, Stripe, Resend, Groq, and ApyHub — each covering a different layer of a typical project, with the real 2026 free-tier limits and an honest note on where each one stops being free or breaks down. Free API lists go viral every other week, and most of them are 300 endpoints nobody will ever call. This is the shorter, honest version: the free tiers worth actually building on, not bookmarking and forgetting. ## Why this matters now The free-tier landscape shifted in the last couple of years, and not all in one direction. Some defaults got more generous; others quietly disappeared — SendGrid, for years the standard answer for "send email from my app," removed its free plan in 2025 and replaced it with a 60-day trial. Picking your stack on outdated "free forever" assumptions is how you end up rewriting an integration three weeks into a project. The five below were all verified against current pricing pages, and each entry says where the free tier actually ends. ## What makes a good free API for a side project Not every "free" API is worth building on. These are the criteria this list is judged against — and they're a useful checklist for anything not on it: 1. **It's permanently free, not a trial.** A 30- or 60-day clock isn't a free tier; it's a countdown to a forced decision. The free tier should still be there next year. 2. **No credit card to start.** You should be able to go from "idea" to "first API call" without a payment method on file. A required card is a small but real barrier — and an easy way to get charged for forgetting to cancel. 3. **It's production-capable, not a toy.** The free tier should run a real (small) project, not just a hello-world demo. "Works until you have a single actual user" doesn't count. 4. **Pricing scales with you, not ahead of you.** The best free tiers are on-ramps: you build the whole thing for free and only start paying once the project is real enough to justify it. 5. **You can test before you commit.** Great docs, a sandbox, or a playground to try a real call before wiring it into your code. ## The five at a glance | API | What it handles | Free tier (no card unless noted) | Best for | | ------------------------------------ | ---------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------- | ----------------------------------- | | [Supabase](https://supabase.com) | Postgres DB, auth, storage, realtime | 500 MB database, 1 GB file storage, \~5 GB egress, 50,000 monthly active users, 2 projects — pauses after 7 days idle | The whole backend for an MVP | | [Stripe](https://stripe.com) | Payments | No monthly fee; test mode free; pay per transaction (≈2.9% + fixed fee, varies by country) | The moment your project takes money | | [Resend](https://resend.com) | Transactional email | 3,000 emails/month, 100/day, 1 verified domain, 30-day logs | Sign-ups, magic links, receipts | | [Groq](https://groq.com) | Fast LLM inference (open models) | All models; \~30 requests/min; \~1,000–14,400 requests/day depending on model | Testing an AI feature cheaply | | [ApyHub](https://apyhub.com/catalog) | Utility APIs (PDF, image, file conversion, QR, data) | Starter €0; full catalog + playground; \~5 API calls/day | Skipping the boring utility code | ## 1. Supabase — your whole backend, free [Supabase](https://supabase.com) is an open-source Firebase alternative built on Postgres: a real database, authentication, file storage, edge functions, and realtime subscriptions, all wired together behind a clean dashboard and auto-generated APIs. For a side project, it's often the entire backend, and the free tier is genuinely usable rather than a demo. **Where it shines** * A real, dedicated Postgres database — not a stripped-down key-value toy. 500 MB holds millions of rows of typical app data. * Auth, storage, and realtime bundled in, so you're not stitching three vendors together. * 50,000 monthly active users on the free tier, which is a real product, not a sandbox. * Open source, so there's a self-host escape hatch and less lock-in panic later. **Where it lags** * Free projects pause after 7 days of inactivity — the single most common gotcha. Your data survives, but the project goes offline until you manually resume it, which is rough for a demo someone opens unannounced. * No automatic backups on the free tier. * Shared compute means response times can climb under load. * Egress is the limit people underestimate — an image-heavy or chatty realtime app can burn through the included bandwidth quickly. ## 2. Stripe — free until you're actually making money [Stripe](https://stripe.com) is the payments layer, and its "free" works differently from the others here: there's no monthly fee and test mode is free forever, so you can build and test an entire checkout flow without paying anything. You only start paying when you take real money — a per-transaction cut rather than a subscription. **Where it shines** * Test mode lets you build the complete payment flow — subscriptions, webhooks, refunds — before charging a cent. * Documentation and developer experience that most APIs are measured against. * You only pay when the project earns, which is exactly the right shape for a side project that may never charge anyone. * A huge ecosystem of libraries, integrations, and examples. **Where it lags** * It's not "free" once real money moves — expect roughly a \~2.9% + fixed-fee cut per transaction, and the exact rate varies by country and payment method. * Availability and supported payout countries vary, which can block some indie builders entirely. * Account, tax, and compliance setup is more involved than dropping in an API key. * Overkill if your side project will never actually charge anyone. ## 3. Resend — transactional email without the tears [Resend](https://resend.com) handles the email every app needs and nobody enjoys wiring up: sign-up confirmations, password resets, magic links, receipts. It's developer-first, with first-class React Email support so you can write templates as React components instead of fighting table-based HTML. **Where it shines** * 3,000 emails per month free is genuinely enough for most early-stage projects. * React Email (JSX templates) is a real DX upgrade if you're already in React or Next.js. * Clean API and well-regarded docs; setup is quick. * Reported median send latency around 92 ms (p50) in third-party benchmarks — fast in practice, though that's a measured figure, not a guaranteed SLA. **Where it lags** * The 100-emails-per-day cap bites before the monthly cap does — a single busy sign-up day can blow through it, which is awkward for staging environments. * Only one verified domain on the free tier. * Account data and logs are US-hosted; there's no fully EU-hosted plan, which matters for some compliance needs. * Published prices have changed without much warning before, so budget for that on paid tiers. ## 4. Groq — the cheapest way to test an AI feature [Groq](https://groq.com) runs open-source LLMs on its custom LPU hardware, and the draw is speed: it serves inference fast enough (500+ tokens/second on some models, by its own reporting) that "is this AI feature any good?" becomes a same-afternoon question. The free tier needs no credit card and gives access to every model. **Where it shines** * No credit card, every model available, and an OpenAI-compatible endpoint so existing code mostly just works. * Genuinely fast inference — a real differentiator for chatbots, coding assistants, or anything user-facing. * The cheapest way to validate an AI idea before paying for tokens. * Generous enough for prototyping: the small Llama 3.1 8B model allows up to \~14,400 requests/day. **Where it lags** * Open-source models only — no GPT, Claude, or Gemini. It's a complement to those, not a replacement. * \~30 requests/minute and per-model daily caps (as low as \~1,000/day on the larger models) throttle real user traffic fast. * Token-per-minute limits (e.g. \~6,000 TPM) can be the real bottleneck on long prompts. * Limits apply at the organization level, so spinning up extra API keys won't get you around them. ## 5. ApyHub — skip rebuilding the boring utilities [ApyHub](https://apyhub.com/catalog) is a marketplace for the utility APIs nearly every project needs but no one wants to build: PDF generation, image processing, file conversion, QR codes, data extraction, and AI utilities — described as 200+ APIs and 1,000+ endpoints behind a single key. The free Starter plan needs no credit card and includes a playground to test any endpoint in the browser before you write a line of code. A real call uses a single `apy-token` header — here, generating a QR code, a common side-project need: ```bash curl --request POST \ --url 'https://api.apyhub.com/generate/qr-code' \ --header 'apy-token: APY_TOKEN' \ --header 'content-type: application/json' \ --data '{ "data": "https://myproject.dev", "size": 300 }' ``` ```json { "data": "https://api.apyhub.com/processed/.png" } ``` *(The `apy-token` auth header is the real pattern; confirm the exact endpoint path and response shape against the live docs before wiring it in.)* **Where it shines** * One key and one billing surface for a long tail of utilities, instead of a separate vendor integration per task. * A browser playground to test any endpoint before integrating. * The full catalog is available even on the free tier — the plan affects usage limits, not which APIs you can touch. * Usage-based "atoms" pricing on paid plans suits utilities whose cost varies by request size. **Where it lags** * The free Starter tier is genuinely limited — on the order of \~5 API calls per day. That's fine for testing and prototyping in the playground, but you'll move to a paid plan quickly to run anything live. * It's a newer, smaller marketplace than the largest incumbents, so the catalog is still growing. * The atoms model takes a moment to reason about compared with flat per-call pricing. [Try ApyHub's free tier →](https://apyhub.com/) ## So which should you use? Resist the urge to crown a winner — these don't compete, they stack. A typical side project uses several at once: Supabase for the backend, Resend for email, Stripe the day it takes money, Groq if there's an AI feature, and ApyHub for the utility work you'd otherwise rebuild by hand. The right question isn't "which one," it's "which layer am I on right now" — and on every one of these layers, the free tier is generous enough to get you to a working thing before you spend anything. The one thing they share: a good free tier isn't charity, it's an on-ramp. Each lets you build the whole thing for free and only starts charging once the project is real. ## Conclusion The best free APIs for side projects in 2026 aren't the ones with the flashiest "free forever" banner — they're the ones whose free tier is a real on-ramp and whose paid tier only kicks in once you'd happily pay. Supabase, Stripe, Resend, Groq, and ApyHub each cover a different layer of a project and let you ship something real for nothing. Build on the free tiers, and upgrade the day the limits start mattering — which, if your side project gets there, is a good problem to have. [Browse the catalog →](https://apyhub.com/catalog) ## FAQ **What are the best free APIs for a side project in 2026?** For most projects: Supabase (backend), Stripe (payments), Resend (email), Groq (AI inference), and ApyHub (utility APIs like PDF, image, and file conversion). Each has a permanent free tier you can start using without a credit card. **Which free APIs don't require a credit card?** Supabase, Resend, Groq, and ApyHub's Starter plan all let you start without a card. Stripe doesn't charge a monthly fee and its test mode is free; you only provide payout details when you're ready to take real money. **Is Supabase really free?** Yes — the free tier includes a 500 MB Postgres database, 1 GB file storage, around 5 GB of egress, and 50,000 monthly active users, with no credit card. The main catch is that free projects pause after 7 days of inactivity and there are no automatic backups. **What's the catch with Resend's free tier?** The monthly limit of 3,000 emails is generous, but the 100-emails-per-day cap is what most projects hit first — a single busy sign-up day can exhaust it. You also get just one verified domain on the free plan. **Is Groq's free tier good enough for a real app?** For prototyping and low-volume use, yes — no credit card, every model, and up to \~14,400 requests/day on the smallest model. But \~30 requests/minute and tighter per-model daily caps mean it throttles quickly under real user traffic, and it only runs open-source models. **What can I do with ApyHub's free tier?** You get full catalog access plus a playground to test any endpoint in the browser, with no credit card. The Starter plan is capped at roughly 5 API calls per day — enough to prototype and evaluate, after which you'd move to a paid plan to run anything in production. **Do I have to pay for Stripe?** There's no subscription fee and test mode is free, so building and testing costs nothing. You pay a per-transaction fee (around 2.9% plus a fixed amount, varying by country) only on real payments — so it's effectively free until your project actually earns. **How do I avoid outgrowing a free API mid-project?** Pick tools whose paid tier scales smoothly from the free one (all five here do), watch the limit that bites first — Supabase's egress and pause, Resend's daily cap, Groq's per-minute and daily caps, ApyHub's daily call cap — and upgrade that one resource when it starts to matter rather than rebuilding on a new provider. *** **About ApyHub** ApyHub is the trusted layer of external APIs — powering developers and AI agents to build awesome applications without rebuilding commodity functionality. With a catalog of 200+ APIs and 1,000+ endpoints available under a single key and one consistent integration pattern, ApyHub lets teams offload the utility layer and focus on what actually makes their product theirs. [**Explore the catalog →**](https://apyhub.com/catalog)