GPT-5 vs Grok 3
Pick GPT-5 for most production and developer use cases — it wins the most benchmarks (tool calling, creative problem solving, constrained rewriting) and posts strong external math/coding scores. Grok 3 ties GPT-5 on nine tests (structured output, long context, multilingual, etc.) but is 50%+ more expensive per token, so it’s only defensible if you have provider-specific needs.
openai
GPT-5
Benchmark Scores
External Benchmarks
Pricing
Input
$1.25/MTok
Output
$10.00/MTok
modelpicker.net
xai
Grok 3
Benchmark Scores
External Benchmarks
Pricing
Input
$3.00/MTok
Output
$15.00/MTok
modelpicker.net
Benchmark Analysis
Our 12-test head-to-head: GPT-5 wins three benchmarks outright — tool calling (GPT-5 5 vs Grok 3 4), creative problem solving (4 vs 3), and constrained rewriting (4 vs 3). Grok 3 does not win any tests. Nine tests are ties: structured output (5/5), strategic analysis (5/5), faithfulness (5/5), classification (4/4), long context (5/5), safety calibration (2/2), persona consistency (5/5), agentic planning (5/5), and multilingual (5/5). Key contextual points: • Tool calling: GPT-5 scores 5/5 and is ranked tied for 1st (1 of 54, tied with 16), while Grok 3 ranks 18 of 54 — this matters for function selection, argument accuracy, and multi-step tool workflows. • Creative problem solving: GPT-5 ranks 9 of 54 vs Grok 3 at 30 of 54 — GPT-5 gives more non-obvious, feasible ideas in our tests. • Constrained rewriting: GPT-5 rank 6 of 53 vs Grok 3 rank 31 — GPT-5 handles strict character/format limits better. • Long context and structured output: both models score 5/5 and tie for top ranks, but GPT-5 offers a much larger context window (400,000 tokens vs Grok 3’s 131,072) and a 128k max output token capability, which is significant for very long documents. • External benchmarks: GPT-5 scores 73.6% on SWE-bench Verified, 98.1% on MATH Level 5, and 91.4% on AIME 2025 (all according to Epoch AI) — Grok 3 has no external scores in the payload. Overall, GPT-5 is the stronger performer for tool-driven workflows, coding/math tasks, and strict-format editing; Grok 3 matches GPT-5 on many baseline capabilities but does not outperform it on any tested metric.
Pricing Analysis
Per-token rates: GPT-5 input $1.25/mTok, output $10/mTok; Grok 3 input $3/mTok, output $15/mTok. Example (50/50 input/output split): per 1M tokens GPT-5 ≈ $5,625 vs Grok 3 ≈ $9,000 (difference $3,375). At 10M tokens: GPT-5 ≈ $56,250 vs Grok 3 ≈ $90,000 (diff $33,750). At 100M tokens: GPT-5 ≈ $562,500 vs Grok 3 ≈ $900,000 (diff $337,500). Extremes: input-only 1M = $1,250 (GPT-5) vs $3,000 (Grok 3); output-only 1M = $10,000 vs $15,000. High-volume apps, startups with tight margins, and consumer-facing services should care most about the gap; per-token differences compound quickly at 10M+ monthly tokens.
Real-World Cost Comparison
Bottom Line
Choose GPT-5 if you need: • Best tool calling and function orchestration (5/5, tied 1st). • Strong coding and math performance (SWE-bench 73.6%, MATH Level 5 98.1%, AIME 91.4% — Epoch AI). • Better creative problem solving and constrained rewriting (4 vs 3). • Very large context windows (400k tokens) or huge outputs (128k). Choose Grok 3 if you need: • A text-only flagship that matches GPT-5 on structured output, long-context retrieval, multilingual output, classification, faithfulness, strategic analysis, agentic planning, and persona consistency, and you accept ~50% higher per-token costs. Grok 3 is reasonable when provider or integration constraints mandate xai, but not justified by wins on our 12-test suite.
How We Test
We test every model against our 12-benchmark suite covering tool calling, agentic planning, creative problem solving, safety calibration, and more. Each test is scored 1–5 by an LLM judge. Read our full methodology.