Model comparison
Kimi K2.5 Instant vs Mercury 2
Kimi K2.5 Instant is the stronger model overall, scoring 42.9 to 38.8 on the Noometry Index.
Last verified . 12 shared benchmarks.
Summary
- They share 12 benchmarks with published results for both. Kimi K2.5 Instant scores higher in 7 categories and Mercury 2 in 0 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in coding, where Kimi K2.5 Instant leads 42.3 to 33.2.
- Kimi K2.5 Instant has downloadable open weights; the other is API-only.
Side by side
| Kimi K2.5 Instant | Mercury 2 | |
|---|---|---|
| Provider | Moonshot AI | Inception |
| Noometry Index | 42.9 | 38.8 |
| Released | — | 2026-02-20 |
| Weights | Open | Proprietary |
| Context window | — | 128K |
| Max output | — | 50K |
| Input $ / M tokens | — | $0.25 |
| Output $ / M tokens | — | $0.75 |
| Results tracked | 18 | 17 |
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Category by category
Coding Kimi K2.5 Instant leads
Kimi K2.5 Instant: 42.3 (#95), Mercury 2: 33.2 (#250)
| Benchmark | Kimi K2.5 Instant | Mercury 2 |
|---|---|---|
| LMArena WebDev | 1404 | 1170 |
| LMArena Coding | 1483 | 1391 |
| SciCode | — | 38.7% |
| WeirdML | — | 43.2% |
| ALE-Bench | — | 785.58 |
Reasoning Kimi K2.5 Instant leads
Kimi K2.5 Instant: 28.5 (#88), Mercury 2: 23.0 (#170)
| Benchmark | Kimi K2.5 Instant | Mercury 2 |
|---|---|---|
| LMArena Hard Prompts | 1443 | 1362 |
| CritPt | — | 0.8% |
Math Not comparable
Kimi K2.5 Instant: 36.6 (#105), Mercury 2: —
| Benchmark | Kimi K2.5 Instant | Mercury 2 |
|---|---|---|
| LMArena Math | 1443 | — |
Knowledge Kimi K2.5 Instant leads
Kimi K2.5 Instant: 39.5 (#121), Mercury 2: 35.6 (#170)
| Benchmark | Kimi K2.5 Instant | Mercury 2 |
|---|---|---|
| LMArena Expert | 1438 | 1358 |
| Vectara Hallucination Rate | — | 12.3% |
Multimodal Not comparable
Kimi K2.5 Instant: 39.5 (#47), Mercury 2: —
| Benchmark | Kimi K2.5 Instant | Mercury 2 |
|---|---|---|
| LMArena Vision | 1254 | — |
Multilingual Kimi K2.5 Instant leads
Kimi K2.5 Instant: 52.2 (#89), Mercury 2: 46.8 (#153)
| Benchmark | Kimi K2.5 Instant | Mercury 2 |
|---|---|---|
| LMArena Non-English | 1406 | 1331 |
| LMArena Chinese | 1450 | 1416 |
| LMArena Russian | 1404 | 1303 |
| LMArena French | 1403 | — |
| LMArena German | 1413 | — |
| LMArena Korean | 1378 | — |
| LMArena Spanish | 1448 | — |
Instruction Following Kimi K2.5 Instant leads
Kimi K2.5 Instant: 75.5 (#61), Mercury 2: 70.4 (#161)
| Benchmark | Kimi K2.5 Instant | Mercury 2 |
|---|---|---|
| LMArena Instruction Following | 1430 | 1328 |
Long Context Kimi K2.5 Instant leads
Kimi K2.5 Instant: 43.8 (#82), Mercury 2: 40.4 (#149)
| Benchmark | Kimi K2.5 Instant | Mercury 2 |
|---|---|---|
| LMArena Longer Query | 1435 | 1329 |
Writing & Preference Kimi K2.5 Instant leads
Kimi K2.5 Instant: 60.8 (#91), Mercury 2: 54.0 (#151)
| Benchmark | Kimi K2.5 Instant | Mercury 2 |
|---|---|---|
| LMArena Text | 1420 | 1355 |
| LMArena Creative Writing | 1379 | 1289 |
| LMArena Multi-Turn | 1427 | 1358 |
Frequently asked questions
Is Kimi K2.5 Instant better than Mercury 2?
Kimi K2.5 Instant is the stronger model overall, scoring 42.9 to 38.8 on the Noometry Index.
Is Kimi K2.5 Instant or Mercury 2 better for coding?
Kimi K2.5 Instant scores higher on coding benchmarks: 42.3 versus 33.2 in the Noometry coding category.
How many benchmarks do Kimi K2.5 Instant and Mercury 2 share?
12 benchmarks have published results for both models. Kimi K2.5 Instant has 18 scored results on Noometry and Mercury 2 has 17.