Gemini 2.5 Flash-Lite
Gemini Flash Lite dominates the budget tier. At $0.075 per 1M input tokens, it's the cheapest paid API available — with a massive 1M context window that budget competitors can't match.
Top 5 Cheapest AI APIs
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| # | Model | Provider | Tier | Input / 1M | Output / 1M | Context | Monthly Cost |
|---|
Cheapest API by Use Case
Chatbot / Customer Support
Best balance of cost and response quality for conversational AI. 1M context handles long conversations. 95% cheaper than GPT-5 for chatbot workloads.
Code Generation
Strong coding performance at budget prices. Handles complex multi-file refactoring. 1M context for large codebases.
RAG / Document Q&A
Cheapest option for high-volume document processing. 1M context window handles entire document sets. Ideal for embedding + retrieval pipelines.
Content Writing
Slightly better output quality than Flash Lite for creative writing. Still extremely cheap. 1M context for long-form content.
Startup MVP
Build and validate your AI feature for几乎零成本. Scale to DeepSeek V4 Flash as you grow. Start free with Google's tier.
Enterprise / Production
Battle-tested at scale with 1M context. Best cost-per-quality ratio for production workloads. SOC 2 compliance available.
Cheapest AI API by Industry
Industry-specific cost guides with compliance requirements, budget tiers, and optimized routing strategies.
Cheapest AI API by Use Case
Optimized for specific AI tasks — each with interactive calculators, model rankings, and routing strategies.
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Frequently Asked Questions
What is the cheapest AI API in 2026?
Google Gemini 2.5 Flash-Lite is the cheapest AI API at $0.075 per 1M input tokens and $0.30 per 1M output tokens, with a 1M context window. For comparison, OpenAI's cheapest model (GPT-oss 20B) costs $0.08/$0.35 per 1M tokens with 128K context.
Which AI API is cheapest for chatbots?
For chatbots, DeepSeek V4 Flash ($0.14/$0.28) and Gemini Flash ($0.10/$0.40) offer the best balance of cost and quality. For high-volume support chatbots, Gemini Flash Lite at $0.075/$0.30 is cheapest but may sacrifice response quality on complex queries.
How much does GPT-5 vs Claude vs Gemini cost?
GPT-5 costs $1.25/$10.00 per 1M tokens (272K context). Claude Sonnet 4.6 costs $3.00/$15.00 (200K context). Gemini 2.5 Pro costs $1.25/$10.00 (1M context). For budget options: GPT-5 mini at $0.25/$2.00, Haiku 4.5 at $1.00/$5.00, Gemini Flash at $0.10/$0.40.
Are there free AI APIs?
Several providers offer free tiers: Google Gemini has a free tier with generous limits. OpenAI offers $5 in free credits for new accounts. Anthropic provides limited free access. Together.ai offers free Llama models with rate limits. These free tiers are enough for development and small projects.
What's the cheapest way to build an AI app?
Start with Gemini Flash Lite ($0.075/M) or DeepSeek V4 Flash ($0.14/M) for development. Use a model routing strategy: cheap models for simple tasks, premium models for complex reasoning. A typical chatbot can run for under $5/month with budget models. Use APIpulse's Budget Planner tool to estimate your exact costs.
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