FAQCutting AI Costs
Batch discounts, model routing, budget models, and the hidden costs to watch when optimising AI API spend.
What is the absolute cheapest AI API right now?
By input cost, Meta Llama 3.1 8B at ~$0.02/MTok input and ~$0.04/MTok output is the cheapest, with Llama 4 Scout next at $0.10 — though both are offered through third-party hosts, so pricing varies by provider. The cheapest we track from a major first-party API is Google Gemini 2.5 Flash-Lite at $0.10/MTok input and $0.40/MTok output ($0.05/$0.20 with batch processing), but since 18 September 2026 Google has limited it to developers who have used it before. For a new project, the cheapest current-generation first-party options we track are tied: OpenAI's GPT-6 Luna ($0.10/$0.50, or $0.05/$0.25 with batch processing) and Anthropic's Claude Haiku 5.5 ($0.10/$0.50, or $0.05/$0.25 with batch), with Meta's Muse Ember ($0.10/$0.50) at the same list price. Haiku 5.5's rate covers prompts up to 100,000 tokens only, rising to $0.50/$2.50 above that, while Luna keeps its rate up to 272K tokens and then rises to $0.20/$0.75, so Luna is the cheaper of the two for long prompts. Muse Ember keeps its rate up to 200K input tokens and then bills $0.30/$1.50.
Is the cheapest AI API also the worst quality?
Not necessarily. Gemini 2.5 Flash-Lite and GPT-6 Luna perform well on most standard tasks. Quality differences mainly show up in complex reasoning, creative writing, and nuanced analysis.
Can I mix budget and premium models?
Absolutely. Many teams use a routing strategy — budget models for simple queries and premium models for complex ones. This can cut costs by 60-80% while maintaining quality where it matters.
Do budget models support batch processing?
Many do. GPT-6 Luna, Claude Haiku 5.5, Gemini 2.5 Flash-Lite, GPT-5.6 Luna, and Mistral Small 4 all offer 50% batch discounts. Hosted Meta Llama models don't, but their list prices are already among the lowest we track, and DeepSeek has no batch API but bills off-peak hours at half price.
How do I switch from a premium to a budget model?
Check our migration guides for step-by-step instructions on switching between providers. Most API formats are similar and require minimal code changes.
Are there hidden costs with budget AI APIs?
Watch for output token costs (often 3-4x input costs), rate limits on free tiers, and potential quality trade-offs on complex tasks. Our comparison table shows all costs transparently.
What's the fastest way to cut AI API costs?
Three levers, in order of typical impact: move non-urgent workloads to batch processing (an instant 50% off with most major providers), cache repeated prompt prefixes, and route simple requests to budget models. Our calculator's "My current spend" mode shows what you'd save by switching models, and its "Workload mix" mode prices a split of request types across models.