GPT-5.4 Mini vs Grok 3

All claims below are from our testing across the 12-test suite. Summary: GPT-5.4 Mini wins constrained rewriting (4 vs 3) and creative problem solving (4 vs 3). Grok 3 wins agentic planning (5 vs 4). The remaining nine tests tie. Detailed walkthrough: - Structured output: tie at 5/5. GPT-5.4 Mini is tied for 1st (tied with 24 others out of 54) and Grok 3 shares that top score; both are reliable for JSON/schema compliance. - Strategic analysis: tie at 5/5; both rank tied for 1st and handle nuanced tradeoffs equally in our tests. - Tool calling: tie at 4/5; both rank 18 of 54 (many models share this score) — expect correct function selection and sequencing in typical setups. - Faithfulness: tie at 5/5; both are tied for 1st (among 55) — strong adherence to source material in our evaluations. - Classification: tie at 4/5; both tied for 1st (with 29 others) — accurate routing/categorization in our tests. - Long context: tie at 5/5; both tied for 1st, but note GPT-5.4 Mini exposes a 400,000 token window vs Grok 3's 131,072 in the payload — Mini gives more headroom for massive retrieval use cases. - Safety calibration: tie at 2/5 (rank 12/55 tied) — both models showed conservative refusal behavior on harmful prompts in our tests. - Persona consistency & Multilingual: ties at 5/5 and top ranks for both — strong character maintenance and non-English output. - Constrained rewriting: GPT-5.4 Mini wins 4 vs Grok 3's 3; Mini ranks 6 of 53 (25 models share that score) vs Grok 3 at rank 31 — Mini is measurably better for tight compression or fixed-width outputs. - Creative problem solving: GPT-5.4 Mini 4 vs Grok 3 3; Mini ranks 9 of 54 vs Grok 3 at 30 — Mini produces more non-obvious, feasible ideas in our tests. - Agentic planning: Grok 3 5 vs GPT-5.4 Mini 4; Grok 3 ties for 1st (with 14 others) while Mini ranks 16 — Grok 3 is stronger at goal decomposition and recovery scenarios. In short: most core capabilities are a draw in our suite; Mini pulls ahead on constrained rewriting and creativity, while Grok 3 leads on agentic planning. Context window and modality differences (Mini supports text+image+file->text; Grok 3 is text->text) are practical differentiators.

Costs are per mTok (per-1k-token unit in the payload). GPT-5.4 Mini: input $0.75 / mTok, output $4.50 / mTok. Grok 3: input $3 / mTok, output $15 / mTok. Cost per 1M tokens = cost_per_mTok × 1000. If you split traffic 50/50 between input and output: - 1M tokens: GPT-5.4 Mini = $2,625; Grok 3 = $9,000. - 10M tokens: GPT-5.4 Mini = $26,250; Grok 3 = $90,000. - 100M tokens: GPT-5.4 Mini = $262,500; Grok 3 = $900,000. If your usage is output-heavy (long generations), differences magnify because Grok 3's output rate is $15/mTok vs Mini's $4.50/mTok. Teams running high-volume APIs, multi-tenant SaaS, or large-scale chatbots should care most about this gap; smaller experimenters or organizations that need Grok 3's agentic-planning edge may accept the premium.

Choose GPT-5.4 Mini if you need cost-efficient, high-throughput inference with large-context and multimodal inputs (images/files), or if your workload values constrained-rewriting and creative idea generation. Choose Grok 3 if your product depends on agentic planning, multi-step goal decomposition, or you accept a significant price premium ($3/$15 per mTok) for that planning edge. If you need both, evaluate Grok 3 on critical planning workflows and run Mini where volume and multimodality dominate.