GPT-5.2 vs Grok 4.20

Overview (12 tests): GPT-5.2 wins 3 tests, Grok 4.20 wins 2, and 7 are ties in our suite. Detailed walk-through: - Strategic analysis: tie at 5/5; both are tied for 1st ("tied for 1st with 25 other models out of 54 tested"), meaning both handle nuanced tradeoff reasoning at top-tier levels in our tests. - Constrained rewriting: tie 4/4 (rank 6 of 53 for both), indicating similar performance compressing content under hard limits. - Creative problem solving: GPT-5.2 wins (5 vs 4); GPT ranks tied for 1st, Grok ranks 9 of 54 — GPT provides more non-obvious, feasible ideas in our tasks. - Tool calling: Grok 4.20 wins (5 vs 4); Grok is tied for 1st on tool calling ("tied for 1st with 16 other models out of 54 tested"), while GPT-5.2 is rank 18 — Grok is better at function selection, argument accuracy, and sequencing for agentic integrations. - Faithfulness: tie 5/5; both tied for 1st (large tie group), so both resist hallucination in our tests. - Classification: tie 4/4; both tied for 1st (GPT display: "tied for 1st with 29 other models"), so routing and categorization are equivalent in practice. - Long context: tie 5/5; both tied for 1st ("tied for 1st with 36 other models"), so retrieval at 30K+ tokens is equally strong. - Persona consistency: tie 5/5; both tied for 1st, so both maintain character well. - Multilingual: tie 5/5; both tied for 1st. - Agentic planning: GPT-5.2 wins (5 vs 4); GPT is tied for 1st ("tied for 1st with 14 other models out of 54 tested") while Grok is rank 16 — GPT better at goal decomposition and failure recovery in our tests. - Structured output: Grok 4.20 wins (5 vs 4); Grok is tied for 1st on structured output while GPT sits at rank 26 — Grok is the safer bet for strict JSON/schema adherence. - Safety calibration: GPT-5.2 wins decisively (5 vs 1); GPT is tied for 1st ("tied for 1st with 4 other models out of 55 tested"), Grok ranks 32 of 55 — GPT is markedly better at refusing harmful requests while permitting legitimate ones in our testing. External benchmarks: GPT-5.2 scores 73.8% on SWE-bench Verified and 96.1% on AIME 2025 (both from Epoch AI), which supports its strength on coding verification and high-level math; Grok 4.20 has no SWE-bench/AIME entries in this payload. In practice: pick GPT-5.2 when you need stronger safety, planning, creative problem-solving, or top-tier math; pick Grok 4.20 when strict format adherence and top-ranked tool calling are primary requirements and you want lower output cost.

Raw prices from the payload: GPT-5.2 charges input $1.75 and output $14 per mTok; Grok 4.20 charges input $2 and output $6 per mTok. Assuming 1 mTok = 1k tokens and a 50/50 input/output split, monthly costs are: 1M tokens — GPT-5.2: $7,875; Grok 4.20: $4,000. 10M tokens — GPT-5.2: $78,750; Grok 4.20: $40,000. 100M tokens — GPT-5.2: $787,500; Grok 4.20: $400,000. That gap grows linearly; GPT-5.2 costs ~2.33x more on combined I/O primarily because its output price ($14) is more than double Grok's ($6). Teams with heavy, continuous inference (customer chat, large-scale content generation, or high-throughput APIs) should care about this difference; experimental or safety-critical projects may justify GPT-5.2’s premium, while cost-sensitive, tool-driven services will likely favor Grok 4.20.

Choose GPT-5.2 if you need the safest, most strategic LLM in our tests — safety calibration 5/5 and agentic planning 5/5, plus 96.1% on AIME 2025 (Epoch AI) — and you can absorb higher output costs. Choose Grok 4.20 if you need the best tool calling and structured output (both 5/5 in our suite), faster, cheaper per-output inference ($6 vs $14 per mTok), and are optimizing for tool-driven production workflows where format and function selection matter most.