Model comparison
GPT-5.1-Codex-Max vs Kimi K3
Head-to-head evidence from 10 shared benchmark results across 4 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-5.1-Codex-Max #90 (Estimated); Kimi K3 #4 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-5.1-Codex-Max and Kimi K3 share 10 comparable benchmark results. 0 of 8 categories are comparable. 3 results are unique to GPT-5.1-Codex-Max; 47 to Kimi K3.
Updated July 23, 2026- Shared results
- 10
- GPT-5.1-Codex-Max only
- 3
- Kimi K3 only
- 47
- Comparable categories
- 0 / 8
Benchmark data for GPT-5.1-Codex-Max and Kimi K3 is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 10 shared benchmark results across 4 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.
Kimi K3 is priced at $3.00 input / $15.00 output per 1M tokens, versus $1.25 input / $10.00 output per 1M tokens for GPT-5.1-Codex-Max. Kimi K3 has the larger context window at 1.05M, compared with 400K for GPT-5.1-Codex-Max.
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 | Kimi K3 |
|---|---|---|---|
| Agentic | GPT-5.1-Codex-MaxNot measured | MarginNo overlap | Kimi K389.5 |
| Knowledge | GPT-5.1-Codex-MaxNot measured | MarginNo overlap | Kimi K361.0 |
| Multimodal | GPT-5.1-Codex-MaxNot measured | MarginNo overlap | Kimi K378.5 |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-5.1-Codex-Max | Kimi K3 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-5.1-Codex-Max$1.25 input / $10 output | Kimi K3$3 input / $15 output | GPT-5.1-Codex-Max has the lower combined listed price. |
| Generation speedtokens per second | GPT-5.1-Codex-MaxNot available | Kimi K3Not available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | GPT-5.1-Codex-MaxNot available | Kimi K3Not available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | GPT-5.1-Codex-Max400K | Kimi K31.05M | Kimi K3 lists the larger context window. |
Benchmark Deep Dive
Agentic22 benchmarks
| Benchmark | GPT-5.1-Codex-Max | Kimi K3 | Result |
|---|---|---|---|
| τ²-bench resultsSource | 83% | — | Not comparable |
| Terminal-Bench 2.0Source | — | 88.3% | Not comparable |
| BrowseCompSource | — | 91.2% | Not comparable |
| DeepSearchQASource | — | 95.0% | Not comparable |
| Toolathlon-VerifiedSource | — | 73.2% | Not comparable |
| MCP AtlasSource | — | 84.2% | Not comparable |
| AutomationBenchSource | — | 30.8% | Not comparable |
| JobBenchSource | — | 52.9% | Not comparable |
| APEX-AgentsSource | — | 37.6% | Not comparable |
| SpreadsheetBench 2Source | — | 34.8% | Not comparable |
| DECK-BenchSource | — | 73.5% | Not comparable |
| AA Agentic IndexSource | — | 50.1% | Not comparable |
| GDPval-AASource | — | 59.0% | Not comparable |
| GDPval-AASource | — | 1679 | Not comparable |
| AA BriefcaseSource | — | 1543 | Not comparable |
| AA AutomationBenchSource | — | 52.7% | Not comparable |
| AA EnterpriseOps-GymSource | — | 45.3% | Not comparable |
| AA Harvey LABSource | — | 94.6% | Not comparable |
| AA Tau3 BankingSource | — | 33.4% | Not comparable |
| aaTerminalBench21Source | — | 85% | Not comparable |
| APEX-Agents-AASource | — | 41.3% | Not comparable |
| AA ITBenchSource | — | 47.7% | Not comparable |
Coding10 benchmarks
| Benchmark | GPT-5.1-Codex-Max | Kimi K3 | Result |
|---|---|---|---|
| Vibe Code BenchSource | 22.17% | — | Not comparable |
| AA-SciCodeSource | 40.2% | 58.7% | Kimi K3 leads |
| deepSweSource | — | 67.5% | Not comparable |
| FrontierSWESource | — | 81.2% | Not comparable |
| ProgramBenchSource | — | 77.8% | Not comparable |
| Kimi Code Bench v2Source | — | 72.9% | Not comparable |
| sweMarathonSource | — | 42% | Not comparable |
| PostTrain BenchSource | — | 36.6% | Not comparable |
| MLS-Bench LiteSource | — | 48.3% | Not comparable |
| AA Coding IndexSource | — | 76.2% | Not comparable |
Reasoning2 benchmarks
Knowledge10 benchmarks
| Benchmark | GPT-5.1-Codex-Max | Kimi K3 | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 34.7% | 57.1% | Kimi K3 leads |
| AA-GPQA DiamondSource | 86.0% | 93.5% | Kimi K3 leads |
| AA-HLESource | 23.4% | 44.3% | Kimi K3 leads |
| AA-Omniscience IndexSource | -6.0% | 18.4% | Kimi K3 leads |
| AA-Omniscience AccuracySource | 39.2% | 46.0% | Kimi K3 leads |
| AA-Omniscience Hallucination RateSource | 74.4% | 50.9% | Kimi K3 leads |
| GPQASource | — | 93.5% | Not comparable |
| GPQA-DSource | — | 93.5% | Not comparable |
| HLESource | — | 56% | Not comparable |
| HLE w/o toolsSource | — | 43.5% | Not comparable |
Multimodal15 benchmarks
| Benchmark | GPT-5.1-Codex-Max | Kimi K3 | Result |
|---|---|---|---|
| AA-MMMU-ProSource | 72.5% | 80.5% | Kimi K3 leads |
| OfficeQA ProSource | — | 63.3% | Not comparable |
| MMMU-ProSource | — | 81.6% | Not comparable |
| MMMU-Pro w/ PythonSource | — | 83.4% | Not comparable |
| CharXiv w/o toolsSource | — | 84.8% | Not comparable |
| CharXivSource | — | 91.3% | Not comparable |
| MathVisionSource | — | 94.3% | Not comparable |
| MathVision w/ PythonSource | — | 97.8% | Not comparable |
| BabyVision w/ PythonSource | — | 85.7% | Not comparable |
| ZeroBenchSource | — | 23.0% | Not comparable |
| ZeroBench w/ PythonSource | — | 41.0% | Not comparable |
| WorldVQA ForceAnswerSource | — | 51.0% | Not comparable |
| OmniDocBenchSource | — | 91.1% | Not comparable |
| PerceptionBenchSource | — | 58.5% | Not comparable |
| Design Arena WebsiteSource | — | 1386 | Not comparable |
Inst. Following1 benchmarks
| Benchmark | GPT-5.1-Codex-Max | Kimi K3 | Result |
|---|---|---|---|
| AA-IFBenchSource | 70.0% | — | Not comparable |
Frequently Asked Questions (3)
Can I compare GPT-5.1-Codex-Max and Kimi K3 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 Kimi K3 today?
GPT-5.1-Codex-Max: $1.25 input / $10.00 output per 1M tokens Kimi K3: $3.00 input / $15.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
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