GPT-4o vs Grok 4

Summary: Across our 12-test suite Grok 4 wins 6 benchmarks, GPT-4o wins 1, and 5 are ties. Details (in our testing):

• Long context: Grok 4 scores 5 vs GPT-4o 4; Grok 4 is tied for 1st of 55 models on long context, while GPT-4o ranks 38 of 55. This matters for retrieval, summarizing large documents, or chat histories beyond 30k tokens.
• Faithfulness: Grok 4 5 vs GPT-4o 4; Grok 4 is tied for 1st of 55 on faithfulness, GPT-4o ranks 34 — Grok 4 is less likely to deviate from source material in our tests.
• Multilingual: Grok 4 5 vs GPT-4o 4; Grok 4 is tied for 1st of 55, GPT-4o ranks 36 — Grok 4 produces higher-quality non-English output in our testing.
• Safety calibration: Grok 4 2 vs GPT-4o 1; Grok 4 ranks 12 of 55 vs GPT-4o 32 of 55 — Grok 4 better refuses harmful requests while allowing legitimate ones in our tests.
• Strategic analysis: Grok 4 5 vs GPT-4o 2; Grok 4 is tied for 1st of 54, GPT-4o ranks 44 — Grok 4 outperforms for nuanced tradeoff reasoning and numeric strategy.
• Constrained rewriting: Grok 4 4 vs GPT-4o 3; Grok 4 ranks 6 of 53 vs GPT-4o 31 — Grok 4 is substantially better at strict character/format constraints.
• Agentic planning: GPT-4o 4 vs Grok 4 3; GPT-4o ranks 16 of 54 vs Grok 42 — GPT-4o is stronger at goal decomposition and failure recovery in our tests.
• Ties (structured output, creative problem solving, tool calling, classification, persona consistency): both models score equally on these; notably both tie at 4 on tool calling and are tied for 1st on classification and persona consistency in our rankings. External benchmarks: GPT-4o has external scores on third-party tests — SWE-bench Verified 31% (Epoch AI), MATH Level 5 53.3% (Epoch AI), AIME 2025 6.4% (Epoch AI). Those external percentages are supplementary and indicate weaknesses on those specific external math/coding benchmarks; Grok 4 has no external scores in the payload to compare. Implication for tasks: pick Grok 4 when you need reliable long-context handling, multilingual parity, safety, strategic analysis, or constrained rewriting. Pick GPT-4o when you need better agentic planning and lower cost per token.

Pricing in the payload is per million tokens: GPT-4o input $2.50 / output $10.00; Grok 4 input $3.00 / output $15.00. Assuming a 50/50 split between input and output tokens, cost per 1M total tokens is $6.25 for GPT-4o vs $9.00 for Grok 4. At 10M tokens/month those are $62.50 vs $90.00; at 100M tokens/month $625 vs $900. The gap grows linearly and favors GPT-4o for high-volume, cost-sensitive products; teams where accuracy on long-context, multilingual support, or safety reduces downstream costs may accept Grok 4's ~44% higher bill ($9.00 vs $6.25 per 1M tokens) for better task outcomes. If your workload is output-heavy (more output than input), the output-rate difference ($10 vs $15 per M) further amplifies Grok 4's higher spend.

Choose GPT-4o if: you need lower-cost inference (input $2.50/output $10 per M), stronger agentic planning (GPT-4o wins that benchmark), or you are optimizing for high-volume usage where price dominates. Choose Grok 4 if: you need top-tier long-context retrieval (Grok 4 scores 5 and ties for 1st), higher faithfulness (5/tied for 1st), better multilingual output (5/tied for 1st), improved safety calibration, or stronger strategic analysis and constrained rewriting — Grok 4 wins 6 benchmarks to GPT-4o's 1 in our tests.