By Price
Best Free LLM API Tier
Free API tiers let you prototype, test integrations, and run low-volume personal projects without entering a credit card. They all have rate limits — none are suitable for production traffic without a paid plan. But for getting started, they’re genuinely useful.
Updated February 2026
What to know before picking a free API tier
Free tiers are not created equal — here’s what actually matters:
Which model is behind it — The most important question. Some providers give you free access to their best model with rate limits. Others give you a weaker model specifically designated for the free tier. Always check which model slug you're calling — not just the provider name.
Requests per minute vs. tokens per day — Rate limits are expressed in different units depending on the provider. RPM (requests per minute) matters for low-latency apps; TPD (tokens per day) matters for high-volume pipelines. Know which constraint is relevant to your use case.
How hard the wall is — Some providers hard-cut you off at the limit; others throttle. Some reset hourly, others daily, others monthly. For burst development work, a daily reset is more annoying than a monthly one with a higher cap.
Paid tier pricing when you graduate — You'll outgrow the free tier eventually. It's worth picking a provider whose paid pricing makes sense at your expected scale — not just the one with the most generous free tier.
Our pick
Google's reasoning-optimized flagship, released February 19, 2026, and currently the #1 ranked model on the Artificial Analysis Intelligence Index (score: 57 out of 115+ models). Gemini 3.1 Pro is a direct upgrade to Gemini 3 Pro — same 1M token context window and same $2/$12 pricing — but with dramatically improved reasoning. AA independently measures it at 94.1% GPQA Diamond, 44.7% HLE, and 95.6% τ²-bench — top of field on all three. The API exposes three thinking tiers (Low / Medium / High) and a 65,536-token output window — the largest published output context of any frontier model. A dedicated custom-tools API endpoint is available for agentic pipeline use. Currently in preview — generally available soon.
Free tier via Google AI Studio
≤200K context: $2/$12 per 1M tokens. >200K tokens: $4/$18 per 1M. Output: up to 65,536 tokens. Free tier: rate-limited (60 req/min). Three thinking tiers (Low/Medium/High) via API. Batch API, context caching, function calling, and search grounding supported. Custom-tools endpoint: gemini-3.1-pro-preview-customtools.
Paid: $2/$12 per 1M tokens
Also consider
Google's November 2025 flagship — deprecated March 9, 2026, replaced by Gemini 3.1 Pro at the same $2/$12 per 1M token price. It led 13 of 16 major benchmarks at launch: 90.8% GPQA Diamond, 87.1% τ²-bench, 138 t/s output speed, and a real 1M-token context window. Two things to know before deploying: an 88% hallucination rate (AA-Omniscience) that requires Search grounding to mitigate, and verbosity that inflates real API costs 4–5× above the listed rate. If you're starting fresh, use 3.1 Pro. Already on 3 Pro? The migration is a model string change.
Free tier via Google AI Studio · Paid: $2/$12/1M
Full review →Google's December 2025 Flash model — distilled from Gemini 3 Pro, and in a result that embarrassed the larger model, it beats Pro on SWE-bench Verified (78% vs 76.2%). At $0.50/$3.00 per 1M tokens with a 1M context window and 214 t/s output speed, it's now the default model powering the Gemini app and AI Mode in Google Search for hundreds of millions of users. The intelligence-to-cost ratio is unusual: GPQA Diamond 90.4%, near-Pro level science reasoning, at one-quarter the API price. One thing to know before production use: a 91% hallucination rate that needs Search grounding to control, and text-only output — no image or audio generation.
Free tier via Google AI Studio · Paid: $0.5/$3/1M
Full review →Released November 17, 2025, Grok 4.1 is xAI's most refined model — a post-training upgrade to Grok 4 that briefly claimed the #1 spot on LMArena (30-position jump) before Gemini 3 Pro and Claude Opus 4.6 overtook it. It leads every frontier model on emotional intelligence (EQ-Bench3: 1586 Elo) and creative writing. It's not trying to win on coding or reasoning — it's trying to be the most compelling AI personality, with the cheapest entry point and real-time X data.
Free tier via xAI (Grok 4.1 Fast) · Paid: $0.2/$0.5/1M
Full review →Bottom line
Free API tiers are best for one thing: getting started without commitment. Pick the highest-quality model that offers a free tier, build your prototype, and evaluate whether the paid pricing at your expected production scale makes sense before locking in. The best free tier for prototyping isn’t always the best provider for production.
None of these free tiers are suitable for production traffic. Budget API (under $1/1M) is the next step up.