GPT-4o vs Grok 3

Summary of test-by-test results from our 12-test suite (scores are on our 1–5 internal scale unless noted):

• Structured output: GPT-4o 4 vs Grok 3 5 — Grok 3 wins and ranks tied for 1st (rank 1 of 54 tied) for JSON/schema adherence; this matters when you need strict format compliance for downstream parsers.
• Strategic analysis: GPT-4o 2 vs Grok 3 5 — Grok 3 wins and ranks tied for 1st, indicating much stronger nuanced tradeoff reasoning and numeric decision-making in our tests.
• Faithfulness: GPT-4o 4 vs Grok 3 5 — Grok 3 wins and ranks tied for 1st, so it more reliably sticks to source material in our tasks.
• Long context: GPT-4o 4 vs Grok 3 5 — Grok 3 wins and ranks tied for 1st on 30K+ retrieval-style tasks, so it performed better on very long-context retrieval in our testing.
• Safety calibration: GPT-4o 1 vs Grok 3 2 — Grok 3 wins (rank 12 of 55 tied); GPT-4o’s safety calibration score is low in our suite and may require extra guardrails.
• Agentic planning: GPT-4o 4 vs Grok 3 5 — Grok 3 wins and ties for 1st, useful when you need reliable goal decomposition and recovery.
• Multilingual: GPT-4o 4 vs Grok 3 5 — Grok 3 wins and ties for 1st, so non-English parity favored Grok 3 in our tests. Ties (no clear winner in our suite): constrained rewriting (3 vs 3), creative problem solving (3 vs 3), tool calling (4 vs 4), classification (4 vs 4), persona consistency (5 vs 5). External benchmarks: GPT-4o also has external results from Epoch AI — SWE-bench Verified 31% (Epoch AI), MATH Level 5 53.3% (Epoch AI), AIME 2025 6.4% (Epoch AI). Note SWE-bench 31% is well below the shared median (p50 70.8%) in our distribution. Grok 3 has no SWE-bench / math external scores in the payload, so we cannot compare them on those external measures here. Rankings context: Grok 3 shows multiple top-tied ranks in our internal suite (structured output, long context, strategic analysis, faithfulness, multilingual, agentic planning), while GPT-4o ties for top in classification and persona consistency but scores below Grok 3 on many production-oriented axes.

Raw rates from the payload: GPT-4o input $2.50 / mTok and output $10.00 / mTok; Grok 3 input $3.00 / mTok and output $15.00 / mTok (GPT-4o is ~66.7% of Grok 3 by priceRatio). To translate to realistic volumes (assuming mTok = 1,000 tokens and a 50/50 split between input/output tokens):

• 1M tokens (500k input / 500k output): GPT-4o = $1,250 (input) + $5,000 (output) = $6,250; Grok 3 = $1,500 + $7,500 = $9,000 (GPT-4o saves $2,750, ~30.6%).
• 10M tokens: GPT-4o ≈ $62,500; Grok 3 ≈ $90,000 (saves $27,500).
• 100M tokens: GPT-4o ≈ $625,000; Grok 3 ≈ $900,000 (saves $275,000). Who should care: any product or API buyer with sustained high-volume usage (>=10M tokens/month) will see material savings with GPT-4o. Teams that prioritize the benchmarks Grok 3 wins (structured output, long-context, faithfulness, multilingual, agentic planning, safety calibration, strategic analysis) should budget for Grok 3’s higher cost or test tradeoffs on lower-cost GPT-4o first.

Choose GPT-4o if: you need multimodal inputs (text+image+file->text), are cost-sensitive at scale (GPT-4o output $10 vs Grok 3 $15), or you plan heavy image-processing and want lower per-token spend. Choose Grok 3 if: you prioritize strict structured outputs (JSON/schema), long-context retrieval, faithfulness, multilingual parity, agentic planning or nuanced strategic analysis — Grok 3 wins those benchmarks in our testing and ranks tied for 1st in many of them. If unsure, pilot Grok 3 for mission-critical pipelines where format fidelity and truthfulness matter, and use GPT-4o for high-volume, multimodal, or budget-constrained deployments.