Model comparison
GPT-5.3 Chat vs Kimi K2.5 Instant
GPT-5.3 Chat and Kimi K2.5 Instant score almost the same on the Noometry Index (42.8 vs 43.6), so choose on price, context window or the category you care about most.
Last verified . 16 shared benchmarks.
Summary
- They share 16 benchmarks with published results for both. GPT-5.3 Chat scores higher in 1 category and Kimi K2.5 Instant in 7 categories; 8 gaps are clear of the uncertainty.
- Kimi K2.5 Instant has downloadable open weights; the other is API-only.
Side by side
| GPT-5.3 Chat | Kimi K2.5 Instant | |
|---|---|---|
| Provider | OpenAI | Moonshot AI |
| Noometry Index | 42.8 | 43.6 |
| Released | 2026-03-03 | — |
| Weights | Proprietary | Open |
| Context window | 128K | — |
| Max output | 16K | — |
| Input $ / M tokens | $1.75 | — |
| Output $ / M tokens | $14 | — |
| Results tracked | 18 | 18 |
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Category by category
Coding Kimi K2.5 Instant leads
GPT-5.3 Chat: 41.4 (#124), Kimi K2.5 Instant: 42.6 (#97)
| Benchmark | GPT-5.3 Chat | Kimi K2.5 Instant |
|---|---|---|
| LMArena Coding | 1408 | 1484 |
| LMArena WebDev | — | 1404 |
Reasoning Kimi K2.5 Instant leads
GPT-5.3 Chat: 28.5 (#102), Kimi K2.5 Instant: 29.7 (#90)
| Benchmark | GPT-5.3 Chat | Kimi K2.5 Instant |
|---|---|---|
| LMArena Hard Prompts | 1399 | 1443 |
Math Kimi K2.5 Instant leads
GPT-5.3 Chat: 38.2 (#142), Kimi K2.5 Instant: 39.4 (#105)
| Benchmark | GPT-5.3 Chat | Kimi K2.5 Instant |
|---|---|---|
| LMArena Math | 1389 | 1442 |
Knowledge Kimi K2.5 Instant leads
GPT-5.3 Chat: 38.8 (#140), Kimi K2.5 Instant: 40.2 (#123)
| Benchmark | GPT-5.3 Chat | Kimi K2.5 Instant |
|---|---|---|
| LMArena Expert | 1397 | 1440 |
Multimodal Not comparable
GPT-5.3 Chat: —, Kimi K2.5 Instant: 40.2 (#50)
| Benchmark | GPT-5.3 Chat | Kimi K2.5 Instant |
|---|---|---|
| LMArena Vision | — | 1254 |
Multilingual Kimi K2.5 Instant leads
GPT-5.3 Chat: 50.3 (#124), Kimi K2.5 Instant: 52.0 (#94)
| Benchmark | GPT-5.3 Chat | Kimi K2.5 Instant |
|---|---|---|
| LMArena Non-English | 1382 | 1406 |
| LMArena Chinese | 1432 | 1449 |
| LMArena French | 1397 | 1403 |
| LMArena German | 1384 | 1413 |
| LMArena Korean | 1346 | 1378 |
| LMArena Russian | 1400 | 1404 |
| LMArena Spanish | 1371 | 1447 |
| LMArena Japanese | 1352 | — |
Instruction Following Kimi K2.5 Instant leads
GPT-5.3 Chat: 72.8 (#129), Kimi K2.5 Instant: 75.3 (#65)
| Benchmark | GPT-5.3 Chat | Kimi K2.5 Instant |
|---|---|---|
| LMArena Instruction Following | 1378 | 1430 |
Long Context Kimi K2.5 Instant leads
GPT-5.3 Chat: 42.6 (#120), Kimi K2.5 Instant: 43.9 (#83)
| Benchmark | GPT-5.3 Chat | Kimi K2.5 Instant |
|---|---|---|
| LMArena Longer Query | 1396 | 1435 |
Writing & Preference GPT-5.3 Chat leads
GPT-5.3 Chat: 63.1 (#68), Kimi K2.5 Instant: 60.6 (#95)
| Benchmark | GPT-5.3 Chat | Kimi K2.5 Instant |
|---|---|---|
| LMArena Text | 1389 | 1420 |
| LMArena Creative Writing | 1355 | 1381 |
| LMArena Multi-Turn | 1412 | 1427 |
| EQ-Bench Creative Writing | 1690 | — |
Frequently asked questions
Is GPT-5.3 Chat better than Kimi K2.5 Instant?
GPT-5.3 Chat and Kimi K2.5 Instant score almost the same on the Noometry Index (42.8 vs 43.6), so choose on price, context window or the category you care about most.
Is GPT-5.3 Chat or Kimi K2.5 Instant better for coding?
Kimi K2.5 Instant scores higher on coding benchmarks: 42.6 versus 41.4 in the Noometry coding category.
How many benchmarks do GPT-5.3 Chat and Kimi K2.5 Instant share?
16 benchmarks have published results for both models. GPT-5.3 Chat has 18 scored results on Noometry and Kimi K2.5 Instant has 18.