R1 vs GPT-5 Nano

Summary of our 12-test head-to-head (scores are from our 1–5 internal suite unless otherwise noted). Wins, ties and contextual ranks come from our testing. R1 wins (5 tests): strategic_analysis — R1 5 vs GPT-5 Nano 4 (R1 tied for 1st of 54 models; strong for nuanced tradeoffs with numbers). constrained_rewriting — R1 4 vs 3 (R1 rank 6 of 53; better at compression within hard limits). creative_problem_solving — R1 5 vs 3 (R1 tied for 1st; better at generating non-obvious, feasible ideas). faithfulness — R1 5 vs 4 (R1 tied for 1st of 55; sticks to source material more reliably in our testing). persona_consistency — R1 5 vs 4 (R1 tied for 1st; stronger at maintaining character and resisting injection attacks). GPT-5 Nano wins (4 tests): structured_output — GPT-5 Nano 5 vs R1 4 (GPT-5 Nano tied for 1st of 54; best for strict JSON/schema adherence). classification — GPT-5 Nano 3 vs R1 2 (GPT-5 Nano rank 31 of 53 vs R1 rank 51 — better for routing/categorization). long_context — GPT-5 Nano 5 vs R1 4 (GPT-5 Nano tied for 1st of 55; better retrieval at 30K+ tokens). safety_calibration — GPT-5 Nano 4 vs R1 1 (GPT-5 Nano rank 6 of 55 vs R1 rank 32; GPT-5 Nano better at refusing harmful requests while permitting legitimate ones). Ties (3 tests): tool_calling — both 4 (both rank 18 of 54; equal for function selection/argument sequencing in our tests). agentic_planning — both 4 (both rank 16 of 54; similar goal decomposition and recovery). multilingual — both 5 (both tied for 1st of 55; equivalent non-English quality). External math benchmarks (Epoch AI): on MATH Level 5 (Epoch AI) GPT-5 Nano scores 95.2% vs R1 93.1%; on AIME 2025 (Epoch AI) GPT-5 Nano 81.1% vs R1 53.3% — GPT-5 Nano has a material advantage on these competition-grade math measures. Practical meaning: pick R1 when you need top-tier strategic reasoning, creative ideation, or strict faithfulness/persona retention. Pick GPT-5 Nano when you need strict structured output, long-context retrieval, safer refusals, better competition-math performance, or much lower cost.

We compare output costs (the payload’s priceRatio is based on output costs). Output price per mTok: R1 $2.50; GPT-5 Nano $0.40 (6.25× cheaper). Assuming you bill only output tokens: 1M tokens = 1,000 mTok → R1 $2,500 vs GPT-5 Nano $400. At 10M tokens → R1 $25,000 vs GPT-5 Nano $4,000. At 100M tokens → R1 $250,000 vs GPT-5 Nano $40,000. Teams building large-scale chat, search, or logging services will see six-figure differences at 100M tokens; startups and high-throughput services should care most about GPT-5 Nano’s lower unit cost. If your workloads are low-volume but require top-tier reasoning, R1’s higher per-token cost may be justified.

Choose R1 if you prioritize: - Strategic, numeric tradeoff reasoning (R1 5 vs 4) - Creative problem solving (R1 5 vs 3) - Faithfulness and persona consistency (R1 5 vs 4) — and you can absorb higher unit costs. Choose GPT-5 Nano if you prioritize: - Cost-efficiency at scale ($0.40 vs $2.50 output/mTok) - Structured output/JSON schema adherence (GPT-5 Nano 5 vs 4) - Long-context retrieval (GPT-5 Nano 5 vs 4) - Stronger safety calibration and markedly better external math results (MATH Level 5: 95.2% vs 93.1%; AIME 2025: 81.1% vs 53.3%).