GPT-4o-mini vs Grok 4.1 Fast

Across our 12 internal benchmarks, Grok 4.1 Fast outscores GPT-4o-mini in 9 categories, ties in 2 (tool calling and classification), and trails in 1 (safety calibration).

Where Grok 4.1 Fast wins clearly:

• Strategic analysis: 5 vs 2. Grok 4.1 Fast ties for 1st among 54 models in our testing; GPT-4o-mini ranks 44th. For tasks involving nuanced tradeoff reasoning with real numbers — financial analysis, product decisions, scenario planning — this gap is significant and practical.
• Creative problem solving: 4 vs 2. Grok 4.1 Fast ranks 9th of 54; GPT-4o-mini ranks 47th. Generating non-obvious, feasible ideas is a category where GPT-4o-mini is near the bottom of the field.
• Faithfulness: 5 vs 3. Grok 4.1 Fast ties for 1st among 55 models; GPT-4o-mini ranks 52nd — third from last. For RAG pipelines or summarization workflows where hallucination is costly, this is a decisive difference.
• Long context: 5 vs 4. Both models support text+image input, but Grok 4.1 Fast scores at the top tier for retrieval accuracy at 30K+ tokens, and critically offers a 2,000,000-token context window versus GPT-4o-mini's 128,000 tokens. Grok 4.1 Fast ties for 1st among 55 models; GPT-4o-mini ranks 38th.
• Multilingual: 5 vs 4. Grok 4.1 Fast ties for 1st among 55 models; GPT-4o-mini ranks 36th. For non-English applications, Grok 4.1 Fast delivers higher-quality output.
• Structured output: 5 vs 4. Grok 4.1 Fast ties for 1st among 54 models; GPT-4o-mini ranks 26th. Better JSON schema compliance matters for any pipeline expecting reliable format adherence.
• Persona consistency: 5 vs 4. Grok 4.1 Fast ties for 1st among 53 models; GPT-4o-mini ranks 38th. Relevant for chatbots, branded assistants, and roleplay applications.
• Constrained rewriting: 4 vs 3. Grok 4.1 Fast ranks 6th of 53; GPT-4o-mini ranks 31st. Compression within hard character limits — ad copy, summaries, UI microcopy — is a real differentiator.
• Agentic planning: 4 vs 3. Grok 4.1 Fast ranks 16th of 54; GPT-4o-mini ranks 42nd. Goal decomposition and failure recovery are essential for multi-step agent workflows.

Where they tie:

• Tool calling: Both score 4/5, both share rank 18 of 54 (with 29 models at this level). Neither is a standout here, but both are competent for standard function-calling tasks.
• Classification: Both score 4/5, tied for 1st among 53 models (30 models share this score). Routing and categorization tasks are equally handled.

Where GPT-4o-mini wins:

• Safety calibration: 4 vs 1. GPT-4o-mini ranks 6th of 55 models; Grok 4.1 Fast ranks 32nd. GPT-4o-mini is meaningfully better at refusing harmful requests while permitting legitimate ones — a critical distinction for consumer-facing applications or regulated industries.

External benchmarks (Epoch AI): Grok 4.1 Fast has no external benchmark scores in the payload. GPT-4o-mini scores 52.6% on MATH Level 5 (rank 13 of 14 models tested) and 6.9% on AIME 2025 (rank 21 of 23) — placing it near the bottom among tested models on both competition math benchmarks. Neither model has a SWE-bench Verified score in the payload.

GPT-4o-mini costs $0.15/MTok input and $0.60/MTok output. Grok 4.1 Fast costs $0.20/MTok input and $0.50/MTok output. At 1M tokens/month in a typical 1:3 input-to-output ratio (~250K input, 750K output), GPT-4o-mini runs about $0.49 vs Grok 4.1 Fast's $0.43 — Grok 4.1 Fast is actually cheaper. Scale to 10M tokens/month under the same ratio and the gap grows: $4.88 vs $4.25, saving roughly $63/month with Grok 4.1 Fast. At 100M tokens/month, that's ~$630/month in Grok 4.1 Fast's favor. The crossover flips only in extremely input-heavy workloads (near 1:0 input-to-output ratio), where GPT-4o-mini's $0.15 input rate creates a slight edge. For customer support, agentic pipelines, or research workflows — all output-heavy by nature — Grok 4.1 Fast is the more economical choice. Developers paying close attention to token economics should model their actual I/O ratio before assuming GPT-4o-mini is the budget pick.

Choose GPT-4o-mini if:

• Safety calibration is a hard requirement — it scores 4/5 (rank 6 of 55) vs Grok 4.1 Fast's 1/5, making it the right choice for consumer-facing or regulated applications.
• You need parameters only GPT-4o-mini supports in the payload: logit_bias, logprobs, presence_penalty, frequency_penalty, top_logprobs, or web_search_options.
• Your workload is heavily input-dominant (near zero output tokens), where the $0.15/MTok input rate creates a cost advantage.
• You need max_output_tokens under 16K and 128K context is sufficient.

Choose Grok 4.1 Fast if:

• You're building agentic, research, or customer support pipelines — its 2M context window, higher agentic planning score (4 vs 3), and faithfulness score (5 vs 3, rank 1) make it purpose-built for these workflows.
• Hallucination risk is a concern: its faithfulness score of 5 vs GPT-4o-mini's 3 (ranked 52nd of 55) is a meaningful reliability difference in RAG or summarization contexts.
• Your output volume is high — at $0.50/MTok output vs $0.60/MTok, Grok 4.1 Fast is cheaper at typical output-heavy usage ratios.
• You need long-document analysis beyond 128K tokens — the 2M context window is a hard capability advantage with no GPT-4o-mini equivalent.
• Your application requires nuanced reasoning, strategic analysis, or creative ideation — Grok 4.1 Fast scores 5 vs 2 and 4 vs 2 respectively on those benchmarks.
• You need optional reasoning tokens (Grok 4.1 Fast supports enable/disable reasoning via the reasoning and include_reasoning parameters).