Grok 3 vs o3

Across our 12-test internal benchmark suite, o3 wins 3 tests outright, Grok 3 wins 3 tests outright, and 6 tests end in a tie. Neither model is a runaway winner, but the nature of each model's wins matters.

Where o3 wins:

• Tool calling: 5/5 vs. 4/5. o3 ties for 1st with 16 other models out of 54 tested; Grok 3 sits at rank 18 of 54 tied with 28 others. For agentic pipelines where function selection, argument accuracy, and sequencing errors compound across steps, this gap is meaningful.
• Creative problem solving: 4/5 vs. 3/5. o3 ranks 9th of 54 models; Grok 3 ranks 30th of 54. This covers non-obvious, specific, feasible ideation — o3 has a real edge for brainstorming, product thinking, and open-ended reasoning.
• Constrained rewriting: 4/5 vs. 3/5. o3 ranks 6th of 53; Grok 3 ranks 31st of 53. Compression within hard character limits is a practical skill for copywriting, summarization, and UI copy tasks.

Where Grok 3 wins:

• Classification: 4/5 vs. 3/5. Grok 3 ties for 1st of 53 models (with 29 others); o3 ranks 31st of 53. If your pipeline depends on accurate routing, intent classification, or categorization, Grok 3 is the clear choice.
• Long context: 5/5 vs. 4/5. Grok 3 ties for 1st of 55 models (with 36 others); o3 ranks 38th of 55. Retrieval accuracy at 30K+ tokens is Grok 3's most differentiating advantage. Note also that Grok 3 has a 131K context window vs. o3's 200K — o3 has the larger window on paper, but Grok 3 performs better within our retrieval tests.
• Safety calibration: 2/5 vs. 1/5. Grok 3 ranks 12th of 55 (tied with 19 others); o3 ranks 32nd of 55. Neither model excels here — both score below the 75th percentile (which is 2/5) — but Grok 3 is meaningfully less likely to refuse legitimate requests or permit harmful ones.

Where they tie (6 tests): structured output, strategic analysis, faithfulness, persona consistency, agentic planning, and multilingual all score identically, with both models sharing top-tier rankings on most. On agentic planning, both tie for 1st of 54 (with 14 other models) — a strong shared result for multi-step autonomous task handling.

External benchmarks (Epoch AI data, o3 only): o3 scores 62.3% on SWE-bench Verified, placing it 9th of 12 models tested — below the 70.8% median among tracked models, meaning it's a solid but not elite performer on real GitHub issue resolution. On MATH Level 5, o3 scores 97.8%, ranking 2nd of 14 models (tied with 2 others) — a standout result for competition-level math. On AIME 2025, o3 scores 83.9%, ranking 12th of 23 models — right at the median (p50 is 83.9%). These external scores reinforce o3's strength in mathematical reasoning, though its SWE-bench position suggests coding agents may find stronger alternatives. No external benchmark data is available for Grok 3 in this payload.

Grok 3 costs $3/M input and $15/M output tokens. o3 costs $2/M input and $8/M output tokens. At 1M output tokens/month, that's $15 vs. $8 — a $7 difference that's easy to absorb. At 10M output tokens/month, the gap grows to $70 vs. $80... wait — Grok 3 costs $150 vs. o3's $80, a $70/month premium. At 100M output tokens/month, Grok 3 runs $1,500 vs. o3's $800 — a $700/month difference. For high-volume production workloads, o3's cost advantage is material. The 1.875x output cost ratio means teams need a clear, specific reason to pay for Grok 3. If your pipeline is dominated by long-context retrieval or classification routing — Grok 3's two genuine wins — the premium may be justified. For general-purpose agentic workloads, o3 delivers more benchmark wins at lower cost.

Choose o3 if: you're building agentic or tool-use pipelines (scores 5/5 on tool calling vs. Grok 3's 4/5), need stronger creative or constrained writing outputs, or want to minimize API costs at scale ($8/M vs. $15/M output). o3 also accepts image and file inputs, which Grok 3 does not support per the data payload — a hard requirement for multimodal workflows. o3's math performance is exceptional: 97.8% on MATH Level 5 (Epoch AI), making it the right call for any numerically intensive application.

Choose Grok 3 if: your workload is classification-heavy (tied for 1st of 53 vs. o3's rank 31), involves long-document retrieval where in-context accuracy matters (tied for 1st of 55 vs. o3's rank 38), or you need stronger safety calibration behavior (2/5 vs. 1/5). Grok 3 also supports a broader parameter set including temperature, top_p, frequency_penalty, presence_penalty, logprobs, and top_logprobs — useful if your application relies on sampling controls that o3 does not expose.