🔌 AI APIs - Developer's Comparison Guide
Every major AI provider offers an API - a way to call AI models programmatically from your own code. This guide compares the top options: pricing, strengths, and when to use each.
🟣
Best for complex tasks
Anthropic API
Claude Opus 4.8, Sonnet 4.6, Haiku 4.5
Best reasoning, long context (200K-1M), safest for production
Sonnet: $3/$15 per 1M tokens (in/out)
🟢
Most popular
OpenAI API
GPT-5.5, GPT-5.5 mini, o-series
Widest ecosystem, best plugin/tool support, most integrations
GPT-5.5: ~$5/$30 per 1M tokens
🔵
Largest context window
Google AI (Gemini API)
Gemini 3.5 Pro, Gemini 3.5 Flash
Massive context window (2M tokens), multimodal, generous free tier
Flash: Free tier + $0.075/$0.30 per 1M
🔴
Best value API
Mistral API
Mistral Large, Medium, Small
Fast, affordable, European (GDPR-friendly), good for coding
Small: $0.20/$0.60 per 1M tokens
⭐
Fastest inference
Groq API
Llama 3.1 70B, Mixtral, Gemma
Extremely fast inference (LPU chips), great for real-time apps
Llama 70B: $0.59/$0.79 per 1M tokens
🤗
Most model variety
Hugging Face Inference API
700K+ open-source models
Access to any open-source model via one API, flexible
Free tier + pay-per-use from $0.06/hr
⚡ Hello World - Your First API Call
Every AI API follows the same pattern: authenticate with an API key, send a message, receive a response. Here is the same call in Python for the three most popular APIs:
Anthropic (Claude)
pip install anthropic
import anthropic
client = anthropic.Anthropic(api_key="sk-ant-...")
message = client.messages.create(
model="claude-3-5-sonnet-20241022",
max_tokens=1024,
messages=[{"role": "user", "content": "Hello!"}]
)
print(message.content[0].text)
OpenAI (GPT)
pip install openai
from openai import OpenAI
client = OpenAI(api_key="sk-...")
response = client.chat.completions.create(
model="gpt-5.5",
messages=[{"role": "user", "content": "Hello!"}]
)
print(response.choices[0].message.content)
Ollama - Local (no API key!)
pip install ollama
import ollama
response = ollama.chat(
model='llama3.1',
messages=[{'role': 'user', 'content': 'Hello!'}]
)
print(response['message']['content'])
💰 Cost Calculator - Rough Guide
APIs charge per token (roughly 1 token ≈ 0.75 words). Here is what typical usage costs:
| Task | Tokens (approx) | Claude Sonnet | GPT-5.5 |
|---|
| Single Q&A | 500 | $0.001 | $0.002 |
| Code review (1 file) | 2,000 | $0.006 | $0.010 |
| Summarize 10-page doc | 5,000 | $0.015 | $0.025 |
| 1,000 Q&As per month | 500K | $1.50 | $2.50 |
| Small app (10K API calls) | 5M | $15.00 | $25.00 |
Prices above are estimates. Always check current pricing at each provider's website. API costs are generally very low for individual developers.