Model comparison
GPT-4o vs Kimi K2
Head-to-head evidence from 13 shared benchmark results across 7 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-4o #165 (Supported); Kimi K2 #189 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-4o and Kimi K2 share 13 comparable benchmark results. 1 of 8 categories are comparable. 0 results are unique to GPT-4o; 1 to Kimi K2.
Updated July 20, 2026- Shared results
- 13
- GPT-4o only
- 0
- Kimi K2 only
- 1
- Comparable categories
- 1 / 8
Pick GPT-4o if you want the stronger benchmark profile. Kimi K2 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 13 shared benchmark results across 7 evidence categories; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
GPT-4o is clearly ahead on the BenchAlign aggregate, 41.49 to 27.19. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-4o is also the more expensive model on tokens at $2.50 input / $10.00 output per 1M tokens, versus $0.60 input / $2.50 output per 1M tokens for Kimi K2. That is roughly 4.0x on output cost alone.
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-4o | Δ | Kimi K2 |
|---|---|---|---|
| Math | GPT-4o0.3 | Margin→ 15.8 | Kimi K216.1 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
FrontierMath v2 (Tiers 1-3)
MathA 0.345%B 21.404%Winner: Kimi K2Δ 21.1FrontierMath v2 (Tiers 1-3): GPT-4o scored 0.345%; Kimi K2 scored 21.404%. Kimi K2 wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-4o | Kimi K2 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-4o$2.5 input / $10 output | Kimi K2$0.6 input / $2.5 output | Kimi K2 has the lower combined listed price. |
| Generation speedtokens per second | GPT-4o131 tok/s | Kimi K243 tok/s | GPT-4o has the higher measured throughput. |
| First-answer latencyseconds to first token | GPT-4o0.81 s | Kimi K21.51 s | GPT-4o reaches the first token sooner. |
| Context windowmaximum listed tokens | GPT-4o128K | Kimi K2128K | Listed context windows are equal. |
Benchmark Deep Dive
Agentic1 benchmarks
| Benchmark | GPT-4o | Kimi K2 | Result |
|---|---|---|---|
| τ²-bench resultsSource | 25.1% | 61.1% | Kimi K2 leads |
Coding1 benchmarks
| Benchmark | GPT-4o | Kimi K2 | Result |
|---|---|---|---|
| AA-SciCodeSource | 33.3% | 34.5% | Kimi K2 leads |
Reasoning2 benchmarks
Knowledge6 benchmarks
| Benchmark | GPT-4o | Kimi K2 | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 11.2% | 19.4% | Kimi K2 leads |
| AA-GPQA DiamondSource | 54.3% | 76.6% | Kimi K2 leads |
| AA-HLESource | 3.3% | 7.0% | Kimi K2 leads |
| AA-Omniscience IndexSource | -10.7% | -27.5% | GPT-4o leads |
| AA-Omniscience AccuracySource | 19.7% | 26.8% | Kimi K2 leads |
| AA-Omniscience Hallucination RateSource | 37.9% | 74.2% | GPT-4o leads |
MathKimi K2 wins2 benchmarks
Multimodal1 benchmarks
| Benchmark | GPT-4o | Kimi K2 | Result |
|---|---|---|---|
| Design Arena WebsiteSource | 864 | 1083 | Kimi K2 leads |
Inst. Following1 benchmarks
| Benchmark | GPT-4o | Kimi K2 | Result |
|---|---|---|---|
| AA-IFBenchSource | 34.3% | 41.5% | Kimi K2 leads |
Frequently Asked Questions (2)
Which is better, GPT-4o or Kimi K2?
GPT-4o is ahead on BenchLM's BenchAlign leaderboard, 41.49 to 27.19. The biggest single separator in this matchup is FrontierMath v2 (Tiers 1-3), where the scores are 0.345% and 21.404%.
Which is better for math, GPT-4o or Kimi K2?
Kimi K2 has the edge for math in this comparison, averaging 16.1 versus 0.3. Inside this category, FrontierMath v2 (Tiers 1-3) is the benchmark that creates the most daylight between them.
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