Model comparison
GPT-5.5 vs Kimi K2.6
Head-to-head evidence from 38 shared benchmark results across 7 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-5.5 #9 (Estimated); Kimi K2.6 #74 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-5.5 and Kimi K2.6 share 38 comparable benchmark results. 5 of 8 categories are comparable. 19 results are unique to GPT-5.5; 13 to Kimi K2.6.
Updated July 22, 2026- Shared results
- 38
- GPT-5.5 only
- 19
- Kimi K2.6 only
- 13
- Comparable categories
- 5 / 8
Pick GPT-5.5 if you want the stronger benchmark profile. Kimi K2.6 only becomes the better choice if mathematics is the priority or you want the cheaper token bill.
Confidence note. This is a partial-evidence comparison with 38 shared benchmark results across 7 evidence categories; 5 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
GPT-5.5 is clearly ahead on the BenchAlign aggregate, 73.51 to 56.79. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.5's sharpest advantage is in knowledge, where it averages 57.8 against 42.2. The single biggest benchmark swing on the page is FrontierMath v2 (Tier 4), 35.400% to 14.580%. Kimi K2.6 does hit back in mathematics, so the answer changes if that is the part of the workload you care about most.
GPT-5.5 is also the more expensive model on tokens at $5.00 input / $30.00 output per 1M tokens, versus $0.95 input / $4.00 output per 1M tokens for Kimi K2.6. That is roughly 7.5x on output cost alone. GPT-5.5 gives you the larger context window at 1M, compared with 256K for Kimi K2.6.
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-5.5 | Δ | Kimi K2.6 |
|---|---|---|---|
| Math | GPT-5.547.6 | Margin→ 19.5 | Kimi K2.667.1 |
| Knowledge | GPT-5.557.8 | Margin← 15.6 | Kimi K2.642.2 |
| Multimodal | GPT-5.570.4 | Margin→ 9.4 | Kimi K2.679.8 |
| Agentic | GPT-5.581.6 | Margin← 8.1 | Kimi K2.673.5 |
| Coding | GPT-5.558.6 | Margin→ 5.8 | Kimi K2.664.4 |
| Reasoning | GPT-5.585.0 | MarginNo overlap | Kimi K2.6Not measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
FrontierMath v2 (Tier 4)
MathA 35.400%B 14.580%Winner: GPT-5.5Δ 20.8FrontierMath v2 (Tier 4): GPT-5.5 scored 35.400%; Kimi K2.6 scored 14.580%. GPT-5.5 wins this benchmark. - Source ↗
HLE
KnowledgeA 52.2%B 34.7%Winner: GPT-5.5Δ 17.5HLE: GPT-5.5 scored 52.2%; Kimi K2.6 scored 34.7%. GPT-5.5 wins this benchmark. - Source ↗
Terminal-Bench 2.0
AgenticA 82%B 66.7%Winner: GPT-5.5Δ 15.3Terminal-Bench 2.0: GPT-5.5 scored 82%; Kimi K2.6 scored 66.7%. GPT-5.5 wins this benchmark. - Source ↗
FrontierMath v2 (Tiers 1-3)
MathA 51.700%B 38.966%Winner: GPT-5.5Δ 12.7FrontierMath v2 (Tiers 1-3): GPT-5.5 scored 51.700%; Kimi K2.6 scored 38.966%. GPT-5.5 wins this benchmark. - Source ↗
OSWorld-Verified
AgenticA 78.7%B 73.1%Winner: GPT-5.5Δ 5.6OSWorld-Verified: GPT-5.5 scored 78.7%; Kimi K2.6 scored 73.1%. GPT-5.5 wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-5.5 | Kimi K2.6 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-5.5$5 input / $30 output | Kimi K2.6$0.95 input / $4 output | Kimi K2.6 has the lower combined listed price. |
| Generation speedtokens per second | GPT-5.5Not available | Kimi K2.6Not available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | GPT-5.5Not available | Kimi K2.6Not available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | GPT-5.51M | Kimi K2.6256K | GPT-5.5 lists the larger context window. |
Benchmark Deep Dive
AgenticGPT-5.5 wins27 benchmarks
| Benchmark | GPT-5.5 | Kimi K2.6 | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 82% | 66.7% | GPT-5.5 leads |
| CyberGymSource | 81.8% | — | Not comparable |
| BrowseCompSource | 84.4% | 83.2% | GPT-5.5 leads |
| OSWorld-VerifiedSource | 78.7% | 73.1% | GPT-5.5 leads |
| MCP AtlasSource | 75.3% | 55.9% | GPT-5.5 leads |
| ToolathlonSource | 55.6% | 50% | GPT-5.5 leads |
| τ²-bench resultsSource | 93.9% | 95.9% | Kimi K2.6 leads |
| AA Agentic IndexSource | 44.9% | 30.3% | GPT-5.5 leads |
| APEX-Agents-AASource | 37.7% | 28.5% | GPT-5.5 leads |
| GDPval-AASource | 49.5% | 34.5% | GPT-5.5 leads |
| GDPval-AASource | 1490 | 1189 | GPT-5.5 leads |
| Gert LabsSource | 72.93% | 56.82% | GPT-5.5 leads |
| ResearchClawBenchSource | 17.0% | 18.0% | Kimi K2.6 leads |
| OSWorld 2.0Source | 13.0% | 4.6% | GPT-5.5 leads |
| JobBenchSource | 42.7% | — | Not comparable |
| ExploitGymSource | 13.4% | — | Not comparable |
| AA BriefcaseSource | 1154 | — | Not comparable |
| AA AutomationBenchSource | 42.1% | — | Not comparable |
| AA EnterpriseOps-GymSource | 46.6% | — | Not comparable |
| AA Harvey LABSource | 86.3% | — | Not comparable |
| AA ITBenchSource | 45.8% | — | Not comparable |
| AA Tau3 BankingSource | 31.3% | — | Not comparable |
| terminalBenchHardSource | 60.6% | 43.9% | GPT-5.5 leads |
| aaTerminalBench21Source | 84.3% | — | Not comparable |
| Claw-EvalSource | — | 62.3% | Not comparable |
| DeepSearchQASource | — | 92.5% | Not comparable |
| WideResearchSource | — | 80.8% | Not comparable |
CodingKimi K2.6 wins13 benchmarks
| Benchmark | GPT-5.5 | Kimi K2.6 | Result |
|---|---|---|---|
| SWE-bench ProSource | 58.6% | 58.6% | Tie |
| Terminal-Bench 2.0Source | 82.0% | 66.7% | GPT-5.5 leads |
| Vibe Code BenchSource | 69.85% | 37.89% | GPT-5.5 leads |
| React Native EvalsSource | 84.7% | — | Not comparable |
| cursorBench31Source | 59.2% | 47.6% | GPT-5.5 leads |
| cursorBench32Source | 58.4% | — | Not comparable |
| AA Coding IndexSource | 74.9% | 61.8% | GPT-5.5 leads |
| AA-SciCodeSource | 56.1% | 53.5% | GPT-5.5 leads |
| FrontierCode 1.1 MainSource | 43.0% | — | Not comparable |
| SWE-bench VerifiedSource | — | 80.2% | Not comparable |
| LiveCodeBench v6Source | — | 89.6% | Not comparable |
| SWE MultilingualSource | — | 76.7% | Not comparable |
| SciCodeSource | — | 52.2% | Not comparable |
Reasoning5 benchmarks
KnowledgeGPT-5.5 wins10 benchmarks
| Benchmark | GPT-5.5 | Kimi K2.6 | Result |
|---|---|---|---|
| GPQASource | 93.6% | 90.5% | GPT-5.5 leads |
| GPQA-DSource | 93.6% | 90.5% | GPT-5.5 leads |
| HLESource | 52.2% | 34.7% | GPT-5.5 leads |
| HLE w/o toolsSource | 41.4% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | 54.8% | 44.2% | GPT-5.5 leads |
| AA-GPQA DiamondSource | 93.5% | 91.1% | GPT-5.5 leads |
| AA-HLESource | 44.3% | 35.9% | GPT-5.5 leads |
| AA-Omniscience IndexSource | 20.1% | 6.4% | GPT-5.5 leads |
| AA-Omniscience AccuracySource | 56.9% | 32.8% | GPT-5.5 leads |
| AA-Omniscience Hallucination RateSource | 85.5% | 39.3% | Kimi K2.6 leads |
MathKimi K2.6 wins6 benchmarks
| Benchmark | GPT-5.5 | Kimi K2.6 | Result |
|---|---|---|---|
| FrontierMath (legacy)Source | 51.7% | — | Not comparable |
| FrontierMath v2 (Tiers 1-3)Source | 51.700% | 38.966% | GPT-5.5 leads |
| FrontierMath v2 (Tier 4)Source | 35.400% | 14.580% | GPT-5.5 leads |
| AIME26Source | — | 96.4% | Not comparable |
| HMMT Feb 2026Source | — | 92.7% | Not comparable |
| MMAnswerBenchSource | — | 86.0% | Not comparable |
MultimodalKimi K2.6 wins8 benchmarks
| Benchmark | GPT-5.5 | Kimi K2.6 | Result |
|---|---|---|---|
| MMMU-ProSource | 81.2% | 79.4% | GPT-5.5 leads |
| MMMU-Pro w/ PythonSource | 83.2% | 80.1% | GPT-5.5 leads |
| OfficeQA ProSource | 54.1% | — | Not comparable |
| AA-MMMU-ProSource | 79.9% | 79.4% | GPT-5.5 leads |
| Design Arena WebsiteSource | 1282 | 1306 | Kimi K2.6 leads |
| CharXivSource | — | 80.4% | Not comparable |
| MathVisionSource | — | 87.4% | Not comparable |
| V*Source | — | 96.9% | Not comparable |
Inst. Following1 benchmarks
| Benchmark | GPT-5.5 | Kimi K2.6 | Result |
|---|---|---|---|
| AA-IFBenchSource | 75.9% | 76.0% | Kimi K2.6 leads |
Frequently Asked Questions (6)
Which is better, GPT-5.5 or Kimi K2.6?
GPT-5.5 is ahead on BenchLM's BenchAlign leaderboard, 73.51 to 56.79. The biggest single separator in this matchup is FrontierMath v2 (Tier 4), where the scores are 35.400% and 14.580%.
Which is better for knowledge tasks, GPT-5.5 or Kimi K2.6?
GPT-5.5 has the edge for knowledge tasks in this comparison, averaging 57.8 versus 42.2. Inside this category, AA-Omniscience Hallucination Rate is the benchmark that creates the most daylight between them.
Which is better for coding, GPT-5.5 or Kimi K2.6?
Kimi K2.6 has the edge for coding in this comparison, averaging 64.4 versus 58.6. Inside this category, Vibe Code Bench is the benchmark that creates the most daylight between them.
Which is better for math, GPT-5.5 or Kimi K2.6?
Kimi K2.6 has the edge for math in this comparison, averaging 67.1 versus 47.6. Inside this category, FrontierMath v2 (Tier 4) is the benchmark that creates the most daylight between them.
Which is better for agentic tasks, GPT-5.5 or Kimi K2.6?
GPT-5.5 has the edge for agentic tasks in this comparison, averaging 81.6 versus 73.5. Inside this category, GDPval-AA is the benchmark that creates the most daylight between them.
Which is better for multimodal and grounded tasks, GPT-5.5 or Kimi K2.6?
Kimi K2.6 has the edge for multimodal and grounded tasks in this comparison, averaging 79.8 versus 70.4. Inside this category, Design Arena Website is the benchmark that creates the most daylight between them.
Self-host vs API cost
Estimates at 50,000 req/day · 1000 tokens/req average.
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