Model comparison
GPT-4.1 vs Kimi K2.5
Kimi K2.5 is the stronger model overall, scoring 48.1 to 35.9 on the Noometry Index.
Last verified . 38 shared benchmarks.
Summary
- They share 38 benchmarks with published results for both. GPT-4.1 scores higher in 1 category and Kimi K2.5 in 9 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in math, where Kimi K2.5 leads 51.8 to 22.3.
- The biggest single-benchmark swing is ARC-AGI-1: 5.5% for GPT-4.1 and 65.3% for Kimi K2.5.
- Kimi K2.5 is cheaper at $0.45 / $2.25 per million input/output tokens, against $2 / $8 for GPT-4.1.
- GPT-4.1 accepts more context: 1.05M tokens versus 262K.
- Kimi K2.5 has downloadable open weights; the other is API-only.
Side by side
| GPT-4.1 | Kimi K2.5 | |
|---|---|---|
| Provider | OpenAI | Moonshot AI |
| Noometry Index | 35.9 | 48.1 |
| Released | 2025-04-14 | 2026-01-27 |
| Weights | Proprietary | Open |
| Context window | 1.05M | 262K |
| Max output | 33K | 262K |
| Input $ / M tokens | $2 | $0.45 |
| Output $ / M tokens | $8 | $2.25 |
| Results tracked | 52 | 51 |
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Category by category
Coding Kimi K2.5 leads
GPT-4.1: 34.4 (#238), Kimi K2.5: 48.8 (#53)
| Benchmark | GPT-4.1 | Kimi K2.5 |
|---|---|---|
| SWE-bench Verified | 48.5% | 73.8% |
| SWE-bench Verified (bash only) | 39.6% | 70.8% |
| WeirdML | 39% | 45.6% |
| LMArena Coding | 1391 | 1474 |
| ALE-Bench | 558.1 | 821.65 |
| Aider Polyglot | 52.4% | — |
| LMArena WebDev | — | 1437 |
| SWE-bench Multilingual | — | 67.3% |
| SciCode | — | 49% |
| CadEval | 42% | — |
Agentic & Tool Use Too close to call
GPT-4.1: 34.7 (#43), Kimi K2.5: 34.2 (#48)
| Benchmark | GPT-4.1 | Kimi K2.5 |
|---|---|---|
| Terminal-Bench | — | 43.2% |
| Berkeley Function Calling Leaderboard | 54% | — |
| OSWorld | — | 63.3% |
| Vending-Bench 2 | — | 1,198 |
Reasoning Kimi K2.5 leads
GPT-4.1: 11.7 (#339), Kimi K2.5: 31.2 (#80)
| Benchmark | GPT-4.1 | Kimi K2.5 |
|---|---|---|
| ARC-AGI-2 | 0.4% | 11.8% |
| SimpleBench | 27% | 46.8% |
| Kagi LLM Benchmark | 52.3% | 78.5% |
| ARC-AGI-1 | 5.5% | 65.3% |
| Chess Puzzles | 6% | 12% |
| EnigmaEval | 2.2% | 3.4% |
| LMArena Hard Prompts | 1384 | 1453 |
| Epoch Capabilities Index | 136.78 | 148.03 |
| NYT Connections (extended) | — | 69.9% |
| CritPt | — | 3.1% |
| Thematic Generalization | — | 69.4% |
| DTBench | 68.3% | — |
| LMCA | 25.6% | — |
| ForecastBench | 61.5 | — |
Math Kimi K2.5 leads
GPT-4.1: 22.3 (#280), Kimi K2.5: 51.8 (#53)
| Benchmark | GPT-4.1 | Kimi K2.5 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 38.3% | 92.2% |
| LMArena Math | 1370 | 1470 |
| FrontierMath (Feb 2025 set) | 5.5% | 27.9% |
| FrontierMath Tier 4 (v1) | 0% | 4.2% |
| FrontierMath (Tiers 1-3) | 6% | — |
| MathArena Final-Answer Competitions | — | 62.3% |
| Omni-MATH | 47.1% | — |
| MATH Level 5 | 83% | — |
Knowledge Kimi K2.5 leads
GPT-4.1: 37.1 (#160), Kimi K2.5: 53.6 (#56)
| Benchmark | GPT-4.1 | Kimi K2.5 |
|---|---|---|
| GPQA Diamond | 66.9% | 87.6% |
| Humanity's Last Exam | 5.4% | 24.4% |
| SimpleQA Verified | 31.1% | 34.3% |
| Vectara Hallucination Rate | 5.6% | 14.2% |
| LMArena Expert | 1364 | 1466 |
| MMLU-Pro | 81.1% | — |
| GPQA (HELM) | 65.9% | — |
Multimodal Kimi K2.5 leads
GPT-4.1: 38.2 (#67), Kimi K2.5: 41.1 (#39)
| Benchmark | GPT-4.1 | Kimi K2.5 |
|---|---|---|
| LMArena Vision | 1211 | 1269 |
| GeoBench | 72% | — |
| LMArena Document | — | 1430 |
Multilingual Kimi K2.5 leads
GPT-4.1: 49.4 (#133), Kimi K2.5: 53.9 (#53)
| Benchmark | GPT-4.1 | Kimi K2.5 |
|---|---|---|
| LMArena Non-English | 1370 | 1433 |
| LMArena Chinese | 1382 | 1495 |
| LMArena French | 1382 | 1454 |
| LMArena German | 1381 | 1441 |
| LMArena Japanese | 1319 | 1421 |
| LMArena Korean | 1339 | 1410 |
| LMArena Russian | 1377 | 1435 |
| LMArena Spanish | 1376 | 1450 |
Instruction Following Kimi K2.5 leads
GPT-4.1: 71.3 (#153), Kimi K2.5: 75.3 (#64)
| Benchmark | GPT-4.1 | Kimi K2.5 |
|---|---|---|
| LMArena Instruction Following | 1367 | 1431 |
| IFEval | 83.8% | — |
Long Context Kimi K2.5 leads
GPT-4.1: 40.0 (#163), Kimi K2.5: 52.1 (#7)
| Benchmark | GPT-4.1 | Kimi K2.5 |
|---|---|---|
| Fiction.LiveBench | 63.9% | 86.1% |
| LMArena Longer Query | 1385 | 1445 |
| CL-bench | — | 19.3% |
| CL-bench Life | — | 13.2% |
Writing & Preference Kimi K2.5 leads
GPT-4.1: 57.6 (#125), Kimi K2.5: 65.1 (#53)
| Benchmark | GPT-4.1 | Kimi K2.5 |
|---|---|---|
| LMArena Text | 1383 | 1445 |
| LMArena Creative Writing | 1363 | 1423 |
| EQ-Bench Creative Writing | 1420 | 1579 |
| LMArena Multi-Turn | 1398 | 1444 |
| WildBench | 85.4% | — |
Frequently asked questions
Is GPT-4.1 better than Kimi K2.5?
Kimi K2.5 is the stronger model overall, scoring 48.1 to 35.9 on the Noometry Index.
Which is cheaper, GPT-4.1 or Kimi K2.5?
Kimi K2.5 is cheaper. It lists at $0.45 per million input tokens and $2.25 per million output tokens; GPT-4.1 lists at $2 and $8.
Is GPT-4.1 or Kimi K2.5 better for coding?
Kimi K2.5 scores higher on coding benchmarks: 48.8 versus 34.4 in the Noometry coding category.
Which has the bigger context window?
GPT-4.1 does, with 1.05M tokens against 262K.
How many benchmarks do GPT-4.1 and Kimi K2.5 share?
38 benchmarks have published results for both models. GPT-4.1 has 52 scored results on Noometry and Kimi K2.5 has 51.