GPT-5 vs Grok 4

In our testing GPT-5 wins 4 benchmarks outright and ties on the rest. Side-by-side: - Tool calling: GPT-5 5 vs Grok 4 4 — GPT-5 tied for 1st (tied with 16 others out of 54), so it’s the safer pick when you need reliable function selection, argument accuracy, and sequencing. - Structured output: 5 vs 4 — GPT-5 tied for 1st of 54 (24 others share top score), meaning better JSON/schema compliance for integrations. - Creative problem solving: 4 vs 3 — GPT-5 ranks 9 of 54 (shared) versus Grok 4 at rank 30; expect more non-obvious, feasible ideas from GPT-5. - Agentic planning: 5 vs 3 — GPT-5 tied for 1st of 54 (14 others share top score); it decomposes goals and recovers from failures more consistently in our tests. Ties (both models match): strategic analysis (5/5 — both tied for 1st), constrained rewriting (4/4), faithfulness (5/5), classification (4/4 — both tied for 1st), long context (5/5 — both tied for 1st), safety calibration (2/2), persona consistency (5/5), multilingual (5/5). Practical meaning: both models handle long contexts (30K+ tokens) and preserve faithfulness and persona equally well in our tests, but GPT-5 gives measurable advantages for tool-driven workflows, strict schema outputs, and creative or multi-step planning. External benchmarks (independent) reinforce GPT-5’s strengths: it scores 73.6% on SWE-bench Verified (Epoch AI), 98.1% on MATH Level 5 (Epoch AI), and 91.4% on AIME 2025 (Epoch AI), highlighting its coding/math capabilities; Grok 4 has no external scores in the payload to compare.

Listed rates: GPT-5 charges $1.25 per input mTok and $10 per output mTok; Grok 4 charges $3 per input mTok and $15 per output mTok. The payload's priceRatio (0.6667) reflects output-rate parity ($10 vs $15). Using a simple 50/50 split of input/output tokens, per-month costs are: GPT-5 = $5,625 (1M tokens), $56,250 (10M), $562,500 (100M); Grok 4 = $9,000 (1M), $90,000 (10M), $900,000 (100M). High-volume customers (10M+ tokens/month) will see six-figure monthly differences: switching from Grok 4 to GPT-5 saves $33,750 at 10M and $337,500 at 100M under the 50/50 assumption. Teams building cost-sensitive services, high-throughput APIs, or large-agent fleets should care most about this gap; experimental or low-volume users may tolerate Grok 4’s higher rates for product-specific reasons.

Choose GPT-5 if you need top tool-calling reliability, strict structured outputs, stronger creative problem solving, or the best math/coding external scores — and you want lower listed token rates ($1.25/$10). Choose Grok 4 if you specifically prefer xai’s model behavior or product integrations and are willing to pay higher rates ($3/$15); Grok 4 ties GPT-5 on faithfulness, long-context retrieval, multilingual output, classification, and strategic analysis, so it’s viable where those properties matter and price is secondary.