Grok 4 vs o3

Across our 12-test suite, wins and ties break out as follows (our testing): Grok 4 wins classification (score 4 vs o3's 3), long-context (5 vs 4), and safety calibration (2 vs 1). o3 wins structured output (5 vs 4), creative problem solving (4 vs 3), tool calling (5 vs 4), and agentic planning (5 vs 3). Five tests tie: strategic analysis (both 5), constrained rewriting (both 4), faithfulness (both 5), persona consistency (both 5), and multilingual (both 5). Concrete implications: - Long-context: Grok 4 scores 5 and is tied for 1st on long context in our rankings, reflecting measurable advantage for retrieval and tasks beyond 30K tokens. Use Grok 4 when you must maintain accuracy across very long inputs. - Tool calling & agentic planning: o3 scores 5 and is tied for 1st on tool calling and agentic planning, so it selects functions, arguments, and decomposes goals more reliably in our tests. - Structured output: o3 scores 5 and is tied for 1st on structured output (JSON schema compliance), making it the safer choice for strict format adherence. - Classification & safety: Grok 4's classification score (4) ties it for 1st with many models in our rankings and its safety calibration (2) beats o3 (1) in our testing — this means Grok 4 is better at refusing harmful requests while permitting legitimate ones in our suite. - Creative problem solving and technical creativity tilt to o3 (4 vs 3), which ranked 9th of 54 for creative problem solving. - External benchmarks (Epoch AI): o3 scores 62.3% on SWE-bench Verified, 97.8% on Math Level 5, and 83.9% on AIME 2025 (these are Epoch AI results, supplementary to our internal tests). Notably, o3 ranks 2nd on MATH Level 5 (tied with two others), supporting its strength on competition-level math tasks. Overall: o3 edges Grok 4 in more categories related to tool use, structured outputs, and problem-solving; Grok 4 leads where very large context, classification, and safety matter.

Grok 4 costs input $3/mTok and output $15/mTok; o3 costs input $2/mTok and output $8/mTok (price ratio 1.875 in the payload). At a balanced 50/50 input-output split: 1M tokens (1,000 mTok) costs Grok 4 = $9,000 (500mTok$3 + 500mTok$15) and o3 = $5,000 (500*$2 + 500*$8). For 10M tokens: Grok 4 = $90,000 vs o3 = $50,000. For 100M tokens: Grok 4 = $900,000 vs o3 = $500,000. If your usage is output-heavy (e.g., 90% output tokens), Grok 4 becomes far more expensive because its output rate is $15/mTok vs $8/mTok for o3. Teams with high-volume inference, large-scale chatbots, or heavy-generation pipelines should care most about this gap; smaller projects or latency-sensitive pilots may accept Grok 4's premium for its 256k context and long-context strengths.

Choose Grok 4 if you need: - Best long-context handling (256k window) and top long context score for retrieval or documents >30K tokens. - Stronger classification and better safety calibration in our tests. Choose o3 if you need: - Lower per-token cost (input $2/output $8 vs Grok $3/$15) for high-volume deployments. - Best-in-test tool calling, agentic planning, structured outputs, and stronger creative problem solving (our testing shows o3 scores 5 on tool calling and agentic planning while Grok 4 scores 4 and 3 respectively). If budget is a major constraint at scale, o3 delivers similar or better capabilities in more categories for a substantially lower recurring cost.