// category · 6 tools · 0 open source
LLM APIs
Developer platforms that expose frontier models programmatically. Compare them on context length, tool use, latency, pricing and data handling terms before you build on top of one.
Choosing a model API
A model API lets your own code call a lab's models and pay per token, separately from any chat subscription. The prices that matter are input and output tokens per million, cache discounts, and whether there is any free allowance.
Free access differs a lot between providers in October 2026:
- Google AI Studio offers a free Gemini API tier with rate limits, the clearest recurring free option from a major lab, though Gemini 4 Argon itself is paid only.
- OpenAI has a Free usage tier and optional complimentary tokens if you share traffic.
- Anthropic gives small signup credits, then prepaid billing. Opus 5.5 costs $4 per million input tokens and $20 per million output, per Anthropic's models overview.
- SpaceXSI (xAI) offers a free Playground, then prepaid credits; grok-4.7 costs $2 and $6, per its pricing docs.
- Cohere gives a free trial key capped at 1,000 calls a month, per Cohere's rate limits page.
Two practical tips. First, many providers accept the OpenAI request format, so switching often means changing only the base URL, key and model name. Second, cache pricing can cut costs sharply when you resend the same long prompt, so compare cached input prices as well as headline rates.
Start with free OpenAI API alternatives for a side by side of free options, is the xAI API free for Grok's billing, and what is an LLM API key for keeping keys safe.
Coherecohere.comCohere API for Command chat models plus Embed and Rerank models used in retrieval and search apps. Trial keys are free but capped at 1,000 calls a month; production keys bill Command per token, Rerank per search and Embed per token embedded.Model APIsFreemiumHN 13
AI21 Labsai21.comIsraeli lab behind the Jamba hybrid SSM-transformer models, aimed at long context enterprise workloads.Model APIsSee siteHN 1
Anthropic APIclaude.comProgrammatic access to Claude models, including tool use, prompt caching, batch processing and computer use capabilities.Model APIsPaid
Google AI Studioaistudio.google.comBrowser workspace for prototyping with Gemini models and generating API keys, with a generous free tier for experimentation.Model APIsFreemium
OpenAI APIplatform.openai.comDeveloper platform for OpenAI's models, with the Responses API, tools, fine tuning, embeddings and realtime voice endpoints.Model APIsPaid
xAI APIx.aiSpaceXSI (formerly xAI) API for Grok models with chat, reasoning, vision and function calling, compatible with common SDKs. Keys and the Console Playground are free; API calls use prepaid credits, with grok-4.7 at $2 per million input and $6 per million output tokens.Model APIsPaid// guides
Guides to LLM APIs
Best Free OpenAI API Alternatives in 2026
Compare free OpenAI API alternatives in 2026: Google AI Studio's free Gemini API, Anthropic signup credits, xAI's free Playground, and OpenAI's own free options.
Is Anthropic API Free? What the Claude API Costs
Is Anthropic API free? Keys are free and new users get a small test credit, but Claude API calls are prepaid per token. Prices, plan credits, student options.
Is xAI API Free? What the Grok API Really Costs
Is the xAI API free? Keys and the Playground are free, but Grok API calls use prepaid credits. Current xAI API prices, rate limits and how to get started.
What Is an LLM API Key? A Plain English Guide
What is an LLM API key? A plain English guide to API keys for OpenAI, Claude, Gemini and Grok: how they work, how billing attaches and how to keep one safe.
What Does AI21 Labs Do in 2026? A Clear Answer
What does AI21 Labs do? The Israeli lab behind Jurassic and Jamba now trains custom models for companies. Its history, products, pivot and what it means for you.
Claude Haiku 5.5 vs GPT-6 Luna: Price, Speed, Access
Claude Haiku 5.5 vs GPT-6 Luna compared: identical $0.10/$0.50 base prices, the 100K vs 272K long prompt catch, specs, safety, free access and which to pick.
GPT-6 Astra vs Claude Fable 5.1: Which Is Better?
GPT-6 Astra vs Claude Fable 5.1 compared on vendor benchmarks, API prices, access limits, safety and where each one wins, plus two cheaper alternatives.
ChatGPT vs LLM: What's the Difference?
ChatGPT vs LLM explained: an LLM is the model that predicts text, while ChatGPT is OpenAI's app built on several of them. See what each is and which you need.
ChatGPT vs Enterprise: Which Plan Do You Need?
ChatGPT vs Enterprise explained: how personal plans, ChatGPT Business and ChatGPT Enterprise differ on price, privacy, admin controls and who should buy each.
Kimi K3.1 Pro: Release, Price and Open Weights
Kimi K3.1 Pro explained: Moonshot's new 1 million token flagship, the Highspeed version, API and plan prices, the November 4 weights date and its cyber limits.
Qwen Chat vs ChatGPT: Which Should You Use?
Qwen Chat vs ChatGPT in October 2026: Alibaba's free Qwen3.8-Max app vs OpenAI's GPT-6 plans, features, privacy, data location and who should pick which.
Claude Duet: Anthropic's New AI Agent Explained
Claude Duet explained: what Anthropic's proactive agent does, who can join the waitlist, what it costs on Pro and Max, its safety limits and how it compares.
ChatGPT vs ChatGPT Classic: Which App to Use?
ChatGPT vs ChatGPT Classic explained: what changed in OpenAI's new desktop app, what Classic still gets, who should switch and how to move over safely.
Muse Wonder: Meta's Frontier Model Explained
Muse Wonder explained: what Meta launched on Oct 12, 2026, Wonder vs Wonder Full, API pricing, Muse Code plans, and how it compares with Muse Spark and Claude.
Meta AI vs ChatGPT (and Gemini): Which Should You Use?
Meta AI vs ChatGPT in October 2026: free in app help vs a standalone GPT-6 workspace, Meta One vs Go/Plus pricing, privacy controls, and who should pick which.
GPT-6 Sol vs Astra vs Luna: Which GPT-6 to Use
GPT-6 Sol vs Astra vs Luna explained: what the tier names mean, GPT-6.1 Sol, API prices, which ChatGPT plans include each model, and which one to pick.
Claude Fable vs Opus vs Mythos: Which Claude to Use
Claude Fable vs Opus vs Mythos, plus Mythos vs Opus 5.5: how Fable 5.1, Opus 5.5, Sonnet 5.5 and Mythos differ in price, speed, safeguards and access.
Gemini 4 Argon Release Date: Now Available
Gemini 4 Argon release date is October 13, 2026. Who can use it in the Gemini app, API, and AI Studio, intro pricing through November 30, and Fairwind access.