CLAUDE.md · price reverts to £5
| Spec | Claude Haiku 4.5 | GPT-4o mini |
|---|---|---|
| Input price (per 1M tokens) | $0.80 | $0.15 |
| Output price (per 1M tokens) | $4.00 | $0.60 |
| Cached input price (per 1M) | $0.08 (prompt caching) | ✗ Not available |
| Batch API discount | 50% off (async) | 50% off (async) |
| Context window | 200,000 tokens | 128,000 tokens |
| Output tokens (max) | 8,192 | 16,384 |
| Vision / image input | ✓ Yes | ✓ Yes |
| Structured output (JSON) | ✓ Yes | ✓ Yes |
| Tool use / function calling | ✓ Yes | ✓ Yes |
| Speed (typical) | Very fast (~50 tok/s) | Very fast (~60 tok/s) |
| Coding quality | High (best-in-tier) | Good |
| Instruction following | Excellent | Good |
| Reasoning depth | Better on complex tasks | Adequate for simple tasks |
| Fine-tuning available | ✗ No (Anthropic) | ✓ Yes (OpenAI) |
| Scenario | GPT-4o mini cost | Claude Haiku + cache cost | Winner |
|---|---|---|---|
| 1M one-shot queries (no system prompt) | $0.15 | $0.80 | GPT-4o mini |
| Chatbot (2K sys prompt, 10M cached reads/day) | $1.50 | $0.80 (cached read: $0.08/M) | Claude Haiku |
| RAG pipeline (5K cached context, 1M queries) | $0.75 | $0.40 (cached) | Claude Haiku |
| Document analysis (repeated 50K doc) | $7.50 | $0.40 (cached) | Claude Haiku |
| High-volume classification (short prompts) | $0.15 | $0.80 | GPT-4o mini |
Model your exact workload at Claude API Cost Calculator. See full token pricing at Prompt Token Pricing.
Choose GPT-4o mini if: you're doing high-volume simple tasks (classification, extraction) with short prompts and no repeated context, you need fine-tuning, or you're already deep in the OpenAI ecosystem. The raw token price is 5× cheaper on input.
Choose Claude Haiku if: your app has a system prompt or repeated context that can be cached (chatbots, RAG, document analysis), you need better coding quality, or you're building in the Anthropic ecosystem. With caching, Haiku's effective cost flips below GPT-4o mini on most real-world workloads — and the quality is meaningfully higher.
Is Claude Haiku or GPT-4o mini cheaper?
GPT-4o mini wins on raw token price ($0.15/M input vs $0.80/M). But Claude Haiku's prompt caching drops cached input to $0.08/M — undercutting GPT-4o mini for any workload with repeated system prompts or document context. For chatbots, RAG pipelines, and document analysis, Claude Haiku + caching is usually cheaper overall. For one-shot queries with no repeated context, GPT-4o mini wins.
Which is faster: Claude Haiku or GPT-4o mini?
Both are among the fastest AI APIs available — typically returning first tokens in under 1 second and generating 50–70 tokens/second. GPT-4o mini is slightly faster in most benchmarks. For latency-sensitive applications, both are suitable; the difference rarely exceeds 20% and varies by traffic load and region.
Is Claude Haiku better than GPT-4o mini for coding?
Yes. Claude Haiku consistently outperforms GPT-4o mini on coding benchmarks despite both being small models. Anthropic's focus on code quality and instruction-following carries through to the Haiku tier — you get fewer hallucinated function names, better multi-file reasoning, and more reliable adherence to coding constraints.
What is the context window difference?
Claude Haiku 4.5 has a 200,000 token context window (approximately 150,000 words). GPT-4o mini has a 128,000 token context window (approximately 96,000 words). For applications that need to process large documents, long conversations, or multiple files in a single API call, Haiku's larger context is a significant advantage.
Can GPT-4o mini be fine-tuned but Claude Haiku cannot?
Correct. OpenAI supports fine-tuning GPT-4o mini for custom classification or style tasks. Anthropic does not currently offer fine-tuning for Claude models. If fine-tuning is a requirement, GPT-4o mini is the only option of the two. That said, prompt engineering and Constitutional AI techniques can often achieve comparable specialization on Claude without fine-tuning.