Model comparison
Kimi K2.5 vs Mercury
Kimi K2.5 is the stronger model overall, scoring 48.1 to 37.6 on the Noometry Index.
Last verified . 9 shared benchmarks.
Summary
- They share 9 benchmarks with published results for both. Kimi K2.5 scores higher in 6 categories and Mercury in 0 categories; 6 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Kimi K2.5 leads 65.1 to 46.2.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 78.5% for Kimi K2.5 and 21.6% for Mercury.
- Kimi K2.5 has downloadable open weights; the other is API-only.
Side by side
| Kimi K2.5 | Mercury | |
|---|---|---|
| Provider | Moonshot AI | Inception |
| Noometry Index | 48.1 | 37.6 |
| Released | 2026-01-27 | — |
| Weights | Open | Proprietary |
| Context window | 262K | — |
| Max output | 262K | — |
| Input $ / M tokens | $0.45 | — |
| Output $ / M tokens | $2.25 | — |
| Results tracked | 51 | 9 |
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Category by category
Coding Kimi K2.5 leads
Kimi K2.5: 48.8 (#53), Mercury: 38.7 (#170)
| Benchmark | Kimi K2.5 | Mercury |
|---|---|---|
| LMArena Coding | 1474 | 1322 |
| SWE-bench Verified | 73.8% | — |
| SWE-bench Verified (bash only) | 70.8% | — |
| LMArena WebDev | 1437 | — |
| SWE-bench Multilingual | 67.3% | — |
| SciCode | 49% | — |
| WeirdML | 45.6% | — |
| ALE-Bench | 821.65 | — |
Agentic & Tool Use Not comparable
Kimi K2.5: 34.2 (#48), Mercury: —
| Benchmark | Kimi K2.5 | Mercury |
|---|---|---|
| Terminal-Bench | 43.2% | — |
| OSWorld | 63.3% | — |
| Vending-Bench 2 | 1,198 | — |
Reasoning Kimi K2.5 leads
Kimi K2.5: 31.2 (#80), Mercury: 17.5 (#293)
| Benchmark | Kimi K2.5 | Mercury |
|---|---|---|
| Kagi LLM Benchmark | 78.5% | 21.6% |
| LMArena Hard Prompts | 1453 | 1285 |
| ARC-AGI-2 | 11.8% | — |
| SimpleBench | 46.8% | — |
| NYT Connections (extended) | 69.9% | — |
| ARC-AGI-1 | 65.3% | — |
| CritPt | 3.1% | — |
| Chess Puzzles | 12% | — |
| EnigmaEval | 3.4% | — |
| Thematic Generalization | 69.4% | — |
| Epoch Capabilities Index | 148.03 | — |
Math Not comparable
Kimi K2.5: 51.8 (#53), Mercury: —
| Benchmark | Kimi K2.5 | Mercury |
|---|---|---|
| MathArena Final-Answer Competitions | 62.3% | — |
| OTIS Mock AIME 2024-2025 | 92.2% | — |
| LMArena Math | 1470 | — |
| FrontierMath (Feb 2025 set) | 27.9% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |
Knowledge Not comparable
Kimi K2.5: 53.6 (#56), Mercury: —
| Benchmark | Kimi K2.5 | Mercury |
|---|---|---|
| GPQA Diamond | 87.6% | — |
| Humanity's Last Exam | 24.4% | — |
| SimpleQA Verified | 34.3% | — |
| Vectara Hallucination Rate | 14.2% | — |
| LMArena Expert | 1466 | — |
Multimodal Not comparable
Kimi K2.5: 41.1 (#39), Mercury: —
| Benchmark | Kimi K2.5 | Mercury |
|---|---|---|
| LMArena Vision | 1269 | — |
| LMArena Document | 1430 | — |
Multilingual Kimi K2.5 leads
Kimi K2.5: 53.9 (#53), Mercury: 41.6 (#206)
| Benchmark | Kimi K2.5 | Mercury |
|---|---|---|
| LMArena Non-English | 1433 | 1260 |
| LMArena Chinese | 1495 | — |
| LMArena French | 1454 | — |
| LMArena German | 1441 | — |
| LMArena Japanese | 1421 | — |
| LMArena Korean | 1410 | — |
| LMArena Russian | 1435 | — |
| LMArena Spanish | 1450 | — |
Instruction Following Kimi K2.5 leads
Kimi K2.5: 75.3 (#64), Mercury: 65.2 (#224)
| Benchmark | Kimi K2.5 | Mercury |
|---|---|---|
| LMArena Instruction Following | 1431 | 1239 |
Long Context Kimi K2.5 leads
Kimi K2.5: 52.1 (#7), Mercury: 38.4 (#198)
| Benchmark | Kimi K2.5 | Mercury |
|---|---|---|
| LMArena Longer Query | 1445 | 1266 |
| Fiction.LiveBench | 86.1% | — |
| CL-bench | 19.3% | — |
| CL-bench Life | 13.2% | — |
Writing & Preference Kimi K2.5 leads
Kimi K2.5: 65.1 (#53), Mercury: 46.2 (#221)
| Benchmark | Kimi K2.5 | Mercury |
|---|---|---|
| LMArena Text | 1445 | 1282 |
| LMArena Creative Writing | 1423 | 1191 |
| LMArena Multi-Turn | 1444 | 1282 |
| EQ-Bench Creative Writing | 1579 | — |
Frequently asked questions
Is Kimi K2.5 better than Mercury?
Kimi K2.5 is the stronger model overall, scoring 48.1 to 37.6 on the Noometry Index.
Is Kimi K2.5 or Mercury better for coding?
Kimi K2.5 scores higher on coding benchmarks: 48.8 versus 38.7 in the Noometry coding category.
How many benchmarks do Kimi K2.5 and Mercury share?
9 benchmarks have published results for both models. Kimi K2.5 has 51 scored results on Noometry and Mercury has 9.