GPT-4o mini vs Claude 3.5 Haiku: Best Cost-Efficient AI? (2026)

Short answer: both are the cheap, fast "small" tier of their families, meant for high-volume tasks where a frontier model is overkill. GPT-4o mini is extremely low-cost and great for classification, extraction, and simple chat at scale. Claude 3.5 Haiku is a touch pricier but strong on instruction-following and coding-flavored tasks, with a larger context. For raw cost-per-token, GPT-4o mini usually wins; for quality on slightly harder tasks, Haiku often edges ahead.

At a glance

GPT-4o miniClaude 3.5 Haiku

VendorOpenAIAnthropic PositionCheapest OpenAI tierFast Claude tier Context128K200K StrengthLowest cost, fastInstruction-following, coding-ish Best forBulk classification/extractionQuality-sensitive cheap tasks

When to use the small tier at all

The whole point is routing: send the easy 80–90% of requests (tagging, routing, short answers, simple extraction) to a small model, and reserve a frontier model for the hard remainder. Done well, this slashes cost with little quality loss.

GPT-4o mini is aggressively cheap and fast — ideal for massive volumes of simple calls. If you can fine-tune it for your task, it gets even better — see GPT-4o mini 微调指南.

Claude 3.5 Haiku costs a bit more but tends to follow instructions more precisely and handles light coding/structured tasks well, with a 200K context for longer inputs.

For structured output from either cheaply, see Pydantic AI vs Instructor.

How to choose

Absolute lowest cost at huge volume? GPT-4o mini.

Slightly harder tasks, need precise instruction-following? Claude 3.5 Haiku.

Long inputs on a budget? Haiku (200K context).

Routing both cheap and frontier models? Use a gateway and decide per request.

FAQ

Are small models good enough? For routine tasks, often yes. Test on your real prompts before assuming you need a frontier model. Which has more context? Claude 3.5 Haiku (200K) vs GPT-4o mini (128K). Can I fine-tune them? GPT-4o mini supports fine-tuning; check current options for Haiku.

Verdict

For pure cost at scale, GPT-4o mini is hard to beat. For a small step up in quality on instruction-following and light coding — especially with long inputs — Claude 3.5 Haiku is worth the slightly higher price. The real win is routing: use these for the easy majority and escalate only the hard cases. Compare the full lineup in our 模型库.

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*Last updated: June 2026. Verify current pricing on the OpenAI and Anthropic sites.*