GPT-5.4 Nano vs Grok 4

Across our 12-test internal benchmark suite, GPT-5.4 Nano wins 4 categories, Grok 4 wins 2, and they tie on 6.

Where GPT-5.4 Nano wins:

• Structured output (5 vs 4): Nano ties for 1st among 54 models tested (with 24 others); Grok 4 ranks 26th of 54. For JSON schema compliance and format adherence — critical in API pipelines — Nano is the cleaner choice.
• Agentic planning (4 vs 3): Nano ranks 16th of 54; Grok 4 ranks 42nd of 54. This tests goal decomposition and failure recovery. A meaningful gap — Grok 4 is below median on this dimension, which matters for multi-step agent workflows.
• Creative problem-solving (4 vs 3): Nano ranks 9th of 54; Grok 4 ranks 30th of 54. For generating non-obvious, feasible ideas, Nano is significantly ahead.
• Safety calibration (3 vs 2): Nano ranks 10th of 55; Grok 4 ranks 12th of 55. Both are below the field median (p50 = 2, so Grok 4 is at the median), but Nano's score of 3 is above median and more reliable at refusing harmful requests while permitting legitimate ones.

Where Grok 4 wins:

• Faithfulness (5 vs 4): Grok 4 ties for 1st among 55 models (with 32 others); Nano ranks 34th of 55. For tasks requiring strict adherence to source material without hallucination — summarization, document Q&A, retrieval-augmented generation — Grok 4 has a real edge.
• Classification (4 vs 3): Grok 4 ties for 1st among 53 models (with 29 others); Nano ranks 31st of 53. Accurate categorization and routing is Grok 4's clearest strength relative to Nano.

Ties (6 categories):

Both models score identically on strategic analysis (5/5, tied 1st of 54), long context (5/5, tied 1st of 55), multilingual (5/5, tied 1st of 55), persona consistency (5/5, tied 1st of 53), constrained rewriting (4/4, rank 6 of 53), and tool calling (4/4, rank 18 of 54). On these dimensions — including the tasks many users run most — neither model holds an advantage.

External benchmark (AIME 2025, Epoch AI):

GPT-5.4 Nano scores 87.8% on AIME 2025, ranking 8th of 23 models tested and sitting above the field median of 83.9%. No AIME 2025 score is present in the payload for Grok 4, so a direct comparison on math reasoning cannot be made. Nano's 87.8% places it above the 75th percentile (90.0%) for this benchmark among models we track.

GPT-5.4 Nano costs $0.20 per 1M input tokens and $1.25 per 1M output tokens. Grok 4 costs $3.00 per 1M input tokens and $15.00 per 1M output tokens — 15× more expensive on input and 12× more on output. In practice:

• At 1M output tokens/month: Nano costs $1.25 vs Grok 4's $15.00 — a $13.75 difference.
• At 10M output tokens/month: Nano costs $12.50 vs $150.00 — saving $137.50.
• At 100M output tokens/month: Nano costs $125 vs $1,500 — saving $1,375 per month.

For high-volume production workloads — customer support pipelines, document processing, real-time APIs — the cost gap is decisive. Grok 4's pricing is justifiable only if faithfulness or classification accuracy are mission-critical and you've exhausted alternatives. Developers on constrained budgets or consumer-facing products should strongly favor Nano. Note that Grok 4 uses reasoning tokens (flagged in its quirks), which may further inflate real-world output costs depending on the task.

Choose GPT-5.4 Nano if:

• You're running agentic pipelines or multi-step automation (scores 4 vs Grok 4's 3; ranks 16th vs 42nd of 54 on agentic planning).
• Your application depends on structured outputs — JSON APIs, form parsing, tool responses (scores 5 vs 4; ranks tied-1st vs 26th).
• You need strong math reasoning: 87.8% on AIME 2025 (Epoch AI), ranking 8th of 23 models in our data.
• Cost matters at any scale — Nano is 12× cheaper on output tokens ($1.25 vs $15/1M).
• You want above-median safety calibration (scores 3, ranks 10th of 55).
• You're building a product where creative ideation or brainstorming is part of the workflow.

Choose Grok 4 if:

• Your primary task is retrieval-augmented generation, document Q&A, or summarization where faithfulness to source material is non-negotiable (scores 5, tied 1st of 55 vs Nano's rank 34th).
• You need top-tier classification or intent routing accuracy (tied 1st of 53 on classification vs Nano's rank 31st).
• Budget is not a constraint and you want a reasoning-native model (Grok 4 uses reasoning tokens by design).
• You need logprobs or top_p control — these parameters are available in Grok 4 but not listed for GPT-5.4 Nano.

The short version: GPT-5.4 Nano is the default pick for most use cases. Grok 4 is a specialized choice for faithfulness-critical applications — and you'll pay heavily for that specialization.