Model comparison
GPT-5.1-Codex-Max vs Grok 4
Head-to-head evidence from 12 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-5.1-Codex-Max #90 (Estimated); Grok 4 #50 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-5.1-Codex-Max and Grok 4 share 12 comparable benchmark results. 0 of 8 categories are comparable. 1 result is unique to GPT-5.1-Codex-Max; 4 to Grok 4.
Updated July 20, 2026- Shared results
- 12
- GPT-5.1-Codex-Max only
- 1
- Grok 4 only
- 4
- Comparable categories
- 0 / 8
Benchmark data for GPT-5.1-Codex-Max and Grok 4 is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 12 shared benchmark results across 6 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
GPT-5.1-Codex-Max has the larger context window at 400K, compared with 128K for Grok 4.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | GPT-5.1-Codex-Max | Δ | Grok 4 |
|---|---|---|---|
| Math | GPT-5.1-Codex-MaxNot measured | MarginNo overlap | Grok 415.3 |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-5.1-Codex-Max | Grok 4 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-5.1-Codex-Max$1.25 input / $10 output | Grok 4Not available | A complete price comparison is not available. |
| Generation speedtokens per second | GPT-5.1-Codex-MaxNot available | Grok 454 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | GPT-5.1-Codex-MaxNot available | Grok 415.60 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | GPT-5.1-Codex-Max400K | Grok 4128K | GPT-5.1-Codex-Max lists the larger context window. |
Benchmark Deep Dive
Agentic2 benchmarks
Coding3 benchmarks
Reasoning2 benchmarks
Knowledge6 benchmarks
| Benchmark | GPT-5.1-Codex-Max | Grok 4 | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 34.7% | 33.3% | GPT-5.1-Codex-Max leads |
| AA-GPQA DiamondSource | 86.0% | 87.7% | Grok 4 leads |
| AA-HLESource | 23.4% | 23.9% | Grok 4 leads |
| AA-Omniscience IndexSource | -6.0% | 3.8% | Grok 4 leads |
| AA-Omniscience AccuracySource | 39.2% | 41.4% | Grok 4 leads |
| AA-Omniscience Hallucination RateSource | 74.4% | 64.2% | Grok 4 leads |
Math2 benchmarks
Multimodal1 benchmarks
| Benchmark | GPT-5.1-Codex-Max | Grok 4 | Result |
|---|---|---|---|
| AA-MMMU-ProSource | 72.5% | 68.8% | GPT-5.1-Codex-Max leads |
Inst. Following1 benchmarks
| Benchmark | GPT-5.1-Codex-Max | Grok 4 | Result |
|---|---|---|---|
| AA-IFBenchSource | 70.0% | 53.7% | GPT-5.1-Codex-Max leads |
Frequently Asked Questions (3)
Can I compare GPT-5.1-Codex-Max and Grok 4 on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
What data is available for GPT-5.1-Codex-Max and Grok 4 today?
GPT-5.1-Codex-Max: $1.25 input / $10.00 output per 1M tokens Grok 4: Pricing unavailable Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
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