Claude Haiku 4.5 vs GPT-4.1 Mini

Head-to-head on our 12-test suite: Claude Haiku 4.5 wins 6 benchmarks (creative problem solving 4 vs 3, strategic analysis 5 vs 4, tool calling 5 vs 4, faithfulness 5 vs 4, classification 4 vs 3, agentic planning 5 vs 4). Notable specifics: - Tool calling: Haiku scores 5 and is "tied for 1st with 16 other models out of 54"; GPT-4.1 Mini scores 4 and ranks "18 of 54." This means Haiku is stronger at function selection, argument accuracy and sequencing in our tests. - Strategic analysis: Haiku’s 5 is tied for 1st (with 25 others); GPT scores 4 (rank 27). For numerical tradeoffs and nuanced reasoning, Haiku showed clearer strengths. - Faithfulness & classification: Haiku scored 5 on faithfulness (tied for 1st) and 4 on classification (tied for 1st), while GPT scored 4 and 3 respectively — Haiku is less likely to stray from source material and routes/labels more accurately in our tests. GPT-4.1 Mini wins constrained rewriting (4 vs Haiku’s 3) and ranks "6 of 53," meaning it better compresses/rewrites within hard limits. - Ties: structured output (4/4, both rank 26), long context (5/5, both tied for 1st), safety calibration (2/2, both rank 12), persona consistency (5/5, both tied for 1st), and multilingual (5/5, both tied for 1st). Practical takeaway: Haiku dominates agentic, tool-driven, and strategic tasks in our suite; GPT-4.1 Mini is the better value and handles constrained rewriting and high-stakes math — it scores 87.3% on MATH Level 5 and 44.7% on AIME 2025 according to Epoch AI, which are useful external data points for math-heavy use cases.

Per the payload, Claude Haiku 4.5 charges $1 per input m-tok and $5 per output m-tok; GPT-4.1 Mini charges $0.40 per input m-tok and $1.60 per output m-tok. Using a 50/50 input/output split (common for chat-style usage) yields: 1M tokens → Haiku $3,000 vs GPT $1,000; 10M tokens → Haiku $30,000 vs GPT $10,000; 100M tokens → Haiku $300,000 vs GPT $100,000. If your workload is output-heavy (e.g., 90% output), the gap widens because Haiku's $5 output rate is 3.125× GPT's $1.6. Teams doing millions of tokens/month or deploying at scale should prefer GPT-4.1 Mini purely on cost; teams prioritizing higher tool-calling accuracy, strategy, or faithfulness may justify Haiku’s premium.

Choose Claude Haiku 4.5 if you need best-in-suite tool calling, agentic planning, strategic analysis, faithfulness, and classification for workflows where correctness and function sequencing matter and you can absorb higher per-token costs. Choose GPT-4.1 Mini if you prioritize lower cost (output $1.60 vs $5), need the enormous ~1,047,576-token context window, or require stronger constrained rewriting and competitive external math performance (MATH Level 5 87.3%, AIME 44.7% per Epoch AI).