2026 年开发者最佳免费 AI API 盘点：Gemini、Groq、OpenRouter 等

You do not need a big budget to build with AI in 2026. Several major providers offer genuinely free API tiers — some without even asking for a credit card. This guide rounds up the best of them, with their real free-tier limits and the kind of project each one suits, so you can start building today at no cost.

Details below were checked against each provider's documentation in September 2026. Free limits and free model lists change often, so confirm the latest on each provider's site before you depend on them.

The best free AI APIs in 2026 are Google Gemini through AI Studio (free tier, no credit card), Groq (free tier for fast open models such as gpt-oss-120b, about 30 requests a minute and 1,000 a day), OpenRouter (25+ free models, 20 requests a minute and 50 a day), Mistral (free Experiment plan with phone verification), Cloudflare Workers AI (10,000 free Neurons a day) and Hugging Face Inference Providers (small monthly free credit). Most accept OpenAI-style requests, so switching is a base-URL change. GitHub Models, once a popular free option, was retired on 30 July 2026.

What "Free" Really Means for AI APIs

Free tiers come in two shapes. Some give you a permanent free allowance measured in requests per minute and per day. Others hand you trial credit that runs out. The picks below lean toward the first kind — ongoing free usage you can build a learning project or a light app on without a bill arriving.

Google Gemini (Google AI Studio)

Google's free tier through AI Studio is the strongest all-rounder. You get access to capable Gemini models, such as Gemini 2.5 Flash and the newer 3.x Flash models, with a roomy free allowance and no credit card to start; your exact per-model limits are shown on AI Studio's rate-limit page. It handles text, code, and images, which makes it a great default for a first AI project. The limits are friendly enough for prototypes and personal tools, and the SDK is clean.

Best for: a free, capable general-purpose model for your first build.

One trade-off to know: on the free tier, Google may use your prompts and responses to improve its products, and human reviewers may read them (this does not apply to users in the EEA, Switzerland or the UK). Don't send private data through it. With Gemini's free tier you can build a chatbot, summarize documents, generate code, or describe images, all without a bill. Our Gemini API free tier tutorial walks through a first project. For many developers it is the only AI API they need while learning, and the move to a paid plan later is straightforward when traffic grows.

Groq

Groq is built for speed. Its free tier serves open models such as OpenAI's gpt-oss-120b and gpt-oss-20b at hundreds of tokens per second. Groq retired its Llama 3.3 70B and Llama 3.1 8B models on 16 August 2026, so older tutorials using llama-3.3-70b-versatile now fail. On the free tier, gpt-oss-120b allows 30 requests a minute and 1,000 a day, enough for testing and light apps, and the API is OpenAI-compatible so it drops into existing code.

Best for: low-latency chat and anything where fast responses matter.

OpenRouter

OpenRouter is a single gateway to more than 500 models, including a rotating set of 25+ completely free ones (their IDs end in :free) such as DeepSeek, Llama, Gemma, and Qwen variants. One API key and one format gives you many models to compare. Free models are limited to 20 requests a minute and 50 a day, rising to 1,000 a day once you have bought at least $10 of credit.

Best for: trying many models through one API to find the best fit.

Because you can swap models with a single parameter, OpenRouter is also the fastest way to benchmark which model answers your prompts best before you settle on one for production.

Hugging Face Inference

Hugging Face's old serverless Inference API has become Inference Providers: one Hugging Face token routes requests to many partner providers through https://router.huggingface.co/v1, with the same OpenAI-style format. Free accounts get a small monthly credit ($0.10 at the time of writing, PRO accounts $2), so it is for trying models rather than running an app. The variety is unmatched — text, image, audio, and more — which makes it ideal for experimenting with specialized models you will not find elsewhere.

Best for: exploring open models across many tasks.

Cloudflare Workers AI

Cloudflare Workers AI runs open models on Cloudflare's network with 10,000 free Neurons (Cloudflare's usage unit) a day on both Free and Paid Workers plans, resetting at midnight UTC. On the Free plan requests simply fail once you reach the daily allocation; on the Paid plan, extra usage costs $0.011 per 1,000 Neurons. It is handy when you want inference close to your users with very little setup.

Best for: edge apps and projects already on Cloudflare.

Note: GitHub Models, which used to offer free rate-limited access to leading models, was fully retired on 30 July 2026; its playground and inference API no longer work. GitHub points users to Microsoft Foundry or GitHub Copilot instead.

Mistral and Other Options

Mistral offers a free Experiment plan on its platform that needs phone verification but no card, with capable open and commercial models at low rate limits, and a clean API that suits European-hosted projects. A few other providers rotate free credits or free models from time to time, including fast-inference startups and aggregators. The takeaway: there is far more free capacity in 2026 than most developers realize, so it pays to keep a shortlist and switch when one provider tightens its limits.

Best for: a capable free alternative and a backup when your main provider is busy.

A Quick Start with a Free API

Most of these speak the OpenAI format, so the same few lines work across providers — you only change the base URL, key, and model. Here is the shape of a call:

Python

import os
from openai import OpenAI

# Groq's free tier; swap base_url, key and model for another provider
client = OpenAI(
    api_key=os.environ["GROQ_API_KEY"],
    base_url="https://api.groq.com/openai/v1",
)

response = client.chat.completions.create(
    model="openai/gpt-oss-20b",
    messages=[{"role": "user", "content": "Say hello in three languages."}],
)

print(response.choices[0].message.content)

To use another provider, change three values: for OpenRouter, https://openrouter.ai/api/v1 with a model ending in :free; for Gemini, https://generativelanguage.googleapis.com/v1beta/openai/ with a model such as gemini-2.5-flash; for Hugging Face, https://router.huggingface.co/v1.

Learn this pattern once and you can switch between free providers in seconds, which is the smartest way to avoid lock-in while you test.

Tips to Stay Within Free Limits

• Cache repeated answers. If the same question comes up often, store the reply instead of calling again.
• Keep prompts short. Trim context to what the model needs, since most limits count tokens, not just requests.
• Batch where you can. Group small tasks into one call to use fewer requests against per-minute caps.
• Use a smaller model for easy work and save the big model for hard tasks — faster and lighter on limits.
• Watch the dashboard. Each provider shows your usage; check it before you ship anything public.

How to Choose

• Want one capable default? Start with Google Gemini.
• Need speed? Use Groq.
• Want model variety? Use OpenRouter.
• Exploring niche or open models? Use Hugging Face.
• Building on the edge? Try Cloudflare Workers AI.
• Want a European provider? Try Mistral's free Experiment plan.

Frequently Asked Questions

Which free AI API needs no credit card?

Google AI Studio, Groq, OpenRouter's free models and Cloudflare Workers AI's free plan all start without a card; Mistral's free plan asks for phone verification instead. Always confirm on the provider's signup page, since policies change.

Are free tiers enough for a real app?

For learning projects, demos, and low-traffic tools, yes. For production traffic you will eventually hit limits and want a paid plan or a cheap provider like DeepSeek.

Can I use these with Python?

Yes. Most offer an OpenAI-compatible endpoint, so the standard openai library works by changing the base URL and key.

Will free models change over time?

Often. Free model lists and limits rotate, and models get retired — Groq retired its Llama 3.3 and 3.1 models in August 2026, and Google shut down Gemini 2.0 Flash in June 2026. Check each provider's deprecations page before you commit a project to a specific model.

When to Move to a Paid Plan

Free tiers are perfect for learning, demos, and low-traffic tools, but there are clear signs it is time to upgrade. If you start hitting rate limits during normal use, if response latency hurts your users, or if you need higher reliability and support for a product people depend on, a paid plan pays for itself. The good news is that the jump does not have to be expensive: low-cost providers like DeepSeek, or a small paid tier on the same provider you already use, often cover real traffic for a few dollars a month. Because most of these APIs share the OpenAI format, moving from a free tier to a paid one is usually a one-line change to your base URL and key — so you can start free with confidence, knowing the upgrade path is painless when you need it.

Wrapping Up

Between Gemini, Groq, OpenRouter, Mistral, Hugging Face, and Cloudflare, you can build almost anything with AI in 2026 without spending a cent to start. For step-by-step code, see our Groq tutorial and OpenRouter tutorial. Pick one, learn the call pattern, and ship a small project — then mix providers as your needs grow.

Looking for more free APIs across weather, finance, search, and data to pair with your AI app? Browse the full free API directory.