GPT-5 Mini vs Grok 3 Mini

Summary of head-to-heads in our 12-test suite (scores 1-5 unless noted):

• Structured output: GPT-5 Mini 5 vs Grok 3 Mini 4 — GPT-5 Mini tied for 1st (tied with 24 others) for JSON/schema compliance, so prefer it when exact format adherence matters.
• Strategic analysis: GPT-5 Mini 5 vs Grok 3 Mini 3 — GPT-5 Mini tied for 1st (with 25 others), showing better nuanced tradeoff reasoning for pricing, financials, or multi-step planning.
• Creative problem solving: GPT-5 Mini 4 vs Grok 3 Mini 3 — GPT-5 Mini (rank 9 of 54) produces more varied, specific feasible ideas in our tests.
• Safety calibration: GPT-5 Mini 3 vs Grok 3 Mini 2 — GPT-5 Mini (rank 10 of 55) more reliably refuses harmful prompts while allowing legitimate ones.
• Agentic planning: GPT-5 Mini 4 vs Grok 3 Mini 3 — GPT-5 Mini (rank 16 of 54) decomposes goals and plans recoveries better in our scenarios.
• Multilingual: GPT-5 Mini 5 vs Grok 3 Mini 4 — GPT-5 Mini tied for 1st (with 34 others), so it gives higher-quality non-English outputs in our tests.
• Tool calling: GPT-5 Mini 3 vs Grok 3 Mini 5 — Grok 3 Mini is tied for 1st (with 16 others) on function selection and argument accuracy; choose Grok when orchestrating external tools and precise function calls.
• Faithfulness: tie 5/5 — both models tied for 1st (with many models), meaning both stick to source material well in our tests.
• Constrained rewriting: tie 4/4 — both rank 6 of 53 for tight-character tasks.
• Classification: tie 4/4 — both tied for 1st (with 29 others) for routing and categorization.
• Long context: tie 5/5 — both tied for 1st (with 36 others), so each handles 30K+ token retrieval comparably in our scenarios.
• Persona consistency: tie 5/5 — both maintain character well. External (Epoch AI) results for GPT-5 Mini: SWE-bench Verified 64.7% (Epoch AI) — in our data GPT-5 Mini ranks 8 of 12 on that coding-resolve benchmark; MATH Level 5 97.8% (Epoch AI) — rank 2 of 14; AIME 2025 86.7% (Epoch AI) — rank 9 of 23. Grok 3 Mini has no external Epoch AI scores in the payload. Practical meaning: GPT-5 Mini is a better choice when you need strict output formats, higher-level reasoning, multilingual fidelity, or strong math performance (MATH Level 5 97.8% in Epoch AI). Grok 3 Mini is superior for reliable tool calling and for teams where output token cost is the dominant budget factor.

Pricing per mTok: GPT-5 Mini input $0.25, output $2.00; Grok 3 Mini input $0.30, output $0.50. For 1M output tokens (1,000 mTok) GPT-5 Mini output cost = $2,000 vs Grok = $500. If you bill both input+output as equal volumes: 1M input + 1M output -> GPT-5 Mini = $2,250 total ($250 input + $2,000 output); Grok 3 Mini = $800 total ($300 input + $500 output). At 10M output tokens GPT-5 Mini output = $20,000 vs Grok = $5,000 (roundtrip: GPT-5 Mini $22,500 vs Grok $8,000). At 100M output tokens GPT-5 Mini output = $200,000 vs Grok = $50,000 (roundtrip: GPT-5 Mini $225,000 vs Grok $80,000). The output-cost gap (4x, priceRatio = 4) matters for high-volume chatbots, SaaS APIs, or inference-heavy pipelines; teams with tens of millions of tokens/month should prefer Grok 3 Mini on cost alone unless GPT-5 Mini’s higher quality on key tests justifies the premium.

Choose GPT-5 Mini if you need: strict JSON/schema compliance, strategic/nuanced reasoning, top multilingual output, or best-in-test math (MATH Level 5 97.8% on Epoch AI). Choose Grok 3 Mini if you need: the cheapest output tokens ($0.50/mtok), top-ranked tool calling (5/5, tied for 1st), or a fast lightweight model for logic-based tool orchestration. If monthly output exceeds ~10M tokens and cost sensitivity is high, favor Grok 3 Mini unless GPT-5 Mini’s higher structured/strategic quality is essential.