GPT-5 Mini vs Grok 3

Score-by-score summary (our 12-test suite):

• Wins for GPT-5 Mini: constrained rewriting 4 vs 3 (ranks 6 of 53 vs Grok 31 of 53) — better at tight compression and hard character limits; creative problem solving 4 vs 3 (rank 9 vs 30) — stronger at non-obvious feasible ideas; safety calibration 3 vs 2 (rank 10 vs 12) — more reliable refusals/permits in our testing.
• Wins for Grok 3: tool calling 4 vs 3 (rank 18 of 54 vs GPT-5 Mini rank 47) — clearly better at function selection, argument accuracy, and sequencing; agentic planning 5 vs 4 (Grok tied for 1st vs GPT-5 Mini rank 16) — superior goal decomposition and failure recovery in our tests.
• Ties (identical scores): structured output 5, strategic analysis 5, faithfulness 5, classification 4, long context 5, persona consistency 5, multilingual 5 — both models perform equivalently on JSON/schema adherence, nuanced tradeoffs, faithfulness, labelling, long-context retrieval, persona sticking, and multilingual output. Context and rankings matter: Grok 3’s advantage on tool calling (rank 18 vs 47) is the most pronounced developer-facing gap; GPT-5 Mini’s higher ranks in constrained rewriting and creative problem solving make it stronger for content-dense transformation tasks. External benchmarks (Epoch AI) supplement our internal suite: GPT-5 Mini scores 64.7% on SWE-bench Verified, 97.8% on Math Level 5, and 86.7% on AIME 2025 (Epoch AI). Grok 3 has no external scores in the payload. These external math/coding results suggest GPT-5 Mini is competitive on rigorous coding/math tasks despite Grok’s tooling edge.

Token pricing from the payload: GPT-5 Mini charges $0.25 per 1k input tokens and $2 per 1k output tokens; Grok 3 charges $3 per 1k input and $15 per 1k output. Per million tokens that translates to: GPT-5 Mini — $250 (1M input) and $2,000 (1M output); Grok 3 — $3,000 (1M input) and $15,000 (1M output). If you run 1M input+1M output tokens/month, GPT-5 Mini costs $2,250 vs Grok 3 at $18,000. At 10M/10M tokens/month multiply those totals by 10 (GPT-5 Mini $22,500 vs Grok 3 $180,000). At 100M/100M multiply by 100 (GPT-5 Mini $225,000 vs Grok 3 $1,800,000). The ~8x input and 7.5x output cost gaps mean high-volume apps, SaaS vendors, and cost-conscious teams should prefer GPT-5 Mini for baseline workloads. Teams that need Grok 3’s tooling or agentic strengths must budget for a large premium.

Choose GPT-5 Mini if you want the best price-to-performance for general-purpose apps, high-volume production, long-context or multimodal inputs (400k token window, text+image+file->text), and stronger constrained rewriting and creative problem solving (scores 4/5). Choose Grok 3 if your product depends on robust tool calling or agentic planning (tool calling 4/5, agentic planning 5/5, and higher tool calling rank), and you can absorb the steep token-cost premium ($3/$15 per 1k tokens).