Model comparison
Kimi K2.5 Instant vs Step 5 Preview
Kimi K2.5 Instant and Step 5 Preview score almost the same on the Noometry Index (42.9 vs 43.8), so choose on price, context window or the category you care about most.
Last verified . 1 shared benchmarks.
StepFunSummary
- They share 1 benchmark with published results for both. Kimi K2.5 Instant scores higher in 0 categories and Step 5 Preview in 2 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Step 5 Preview leads 38.0 to 28.5.
- Kimi K2.5 Instant has downloadable open weights; the other is API-only.
Side by side
| Kimi K2.5 Instant | Step 5 Preview | |
|---|---|---|
| Provider | Moonshot AI | StepFun |
| Noometry Index | 42.9 | 43.8 |
| Released | — | 2026-09-16 |
| Weights | Open | Proprietary |
| Context window | — | 1.02M |
| Max output | — | 66K |
| Input $ / M tokens | — | $1 |
| Output $ / M tokens | — | $2.70 |
| Results tracked | 18 | 3 |
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Category by category
Coding Step 5 Preview leads
Kimi K2.5 Instant: 42.3 (#95), Step 5 Preview: 50.6 (#40)
| Benchmark | Kimi K2.5 Instant | Step 5 Preview |
|---|---|---|
| LMArena WebDev | 1404 | 1569 |
| SciCode | — | 58.9% |
| LMArena Coding | 1483 | — |
Reasoning Step 5 Preview leads
Kimi K2.5 Instant: 28.5 (#88), Step 5 Preview: 38.0 (#58)
| Benchmark | Kimi K2.5 Instant | Step 5 Preview |
|---|---|---|
| CritPt | — | 20.9% |
| LMArena Hard Prompts | 1443 | — |
Math Not comparable
Kimi K2.5 Instant: 36.6 (#105), Step 5 Preview: —
| Benchmark | Kimi K2.5 Instant | Step 5 Preview |
|---|---|---|
| LMArena Math | 1443 | — |
Knowledge Not comparable
Kimi K2.5 Instant: 39.5 (#121), Step 5 Preview: —
| Benchmark | Kimi K2.5 Instant | Step 5 Preview |
|---|---|---|
| LMArena Expert | 1438 | — |
Multimodal Not comparable
Kimi K2.5 Instant: 39.5 (#47), Step 5 Preview: —
| Benchmark | Kimi K2.5 Instant | Step 5 Preview |
|---|---|---|
| LMArena Vision | 1254 | — |
Multilingual Not comparable
Kimi K2.5 Instant: 52.2 (#89), Step 5 Preview: —
| Benchmark | Kimi K2.5 Instant | Step 5 Preview |
|---|---|---|
| LMArena Non-English | 1406 | — |
| LMArena Chinese | 1450 | — |
| LMArena French | 1403 | — |
| LMArena German | 1413 | — |
| LMArena Korean | 1378 | — |
| LMArena Russian | 1404 | — |
| LMArena Spanish | 1448 | — |
Instruction Following Not comparable
Kimi K2.5 Instant: 75.5 (#61), Step 5 Preview: —
| Benchmark | Kimi K2.5 Instant | Step 5 Preview |
|---|---|---|
| LMArena Instruction Following | 1430 | — |
Long Context Not comparable
Kimi K2.5 Instant: 43.8 (#82), Step 5 Preview: —
| Benchmark | Kimi K2.5 Instant | Step 5 Preview |
|---|---|---|
| LMArena Longer Query | 1435 | — |
Writing & Preference Not comparable
Kimi K2.5 Instant: 60.8 (#91), Step 5 Preview: —
| Benchmark | Kimi K2.5 Instant | Step 5 Preview |
|---|---|---|
| LMArena Text | 1420 | — |
| LMArena Creative Writing | 1379 | — |
| LMArena Multi-Turn | 1427 | — |
Frequently asked questions
Is Kimi K2.5 Instant better than Step 5 Preview?
Kimi K2.5 Instant and Step 5 Preview score almost the same on the Noometry Index (42.9 vs 43.8), so choose on price, context window or the category you care about most.
Is Kimi K2.5 Instant or Step 5 Preview better for coding?
Step 5 Preview scores higher on coding benchmarks: 50.6 versus 42.3 in the Noometry coding category.
How many benchmarks do Kimi K2.5 Instant and Step 5 Preview share?
1 benchmark has published results for both models. Kimi K2.5 Instant has 18 scored results on Noometry and Step 5 Preview has 3.