Model comparison
GPT-5.3 Chat vs Muse Glimmer
GPT-5.3 Chat and Muse Glimmer score almost the same on the Noometry Index (42.1 vs 41.3), so choose on price, context window or the category you care about most.
Last verified . 12 shared benchmarks.
MetaSummary
- They share 12 benchmarks with published results for both. GPT-5.3 Chat scores higher in 6 categories and Muse Glimmer in 2 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where GPT-5.3 Chat leads 63.3 to 57.7.
- Muse Glimmer has downloadable open weights; the other is API-only.
Side by side
| GPT-5.3 Chat | Muse Glimmer | |
|---|---|---|
| Provider | OpenAI | Meta |
| Noometry Index | 42.1 | 41.3 |
| 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 | 13 |
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Category by category
Coding GPT-5.3 Chat leads
GPT-5.3 Chat: 40.8 (#124), Muse Glimmer: 38.7 (#157)
| Benchmark | GPT-5.3 Chat | Muse Glimmer |
|---|---|---|
| LMArena Coding | 1408 | 1417 |
| LMArena WebDev | — | 1355 |
Reasoning Too close to call
GPT-5.3 Chat: 27.3 (#105), Muse Glimmer: 27.2 (#111)
| Benchmark | GPT-5.3 Chat | Muse Glimmer |
|---|---|---|
| LMArena Hard Prompts | 1399 | 1395 |
Math Too close to call
GPT-5.3 Chat: 35.4 (#146), Muse Glimmer: 36.1 (#128)
| Benchmark | GPT-5.3 Chat | Muse Glimmer |
|---|---|---|
| LMArena Math | 1389 | 1419 |
Knowledge Too close to call
GPT-5.3 Chat: 38.2 (#137), Muse Glimmer: 37.9 (#140)
| Benchmark | GPT-5.3 Chat | Muse Glimmer |
|---|---|---|
| LMArena Expert | 1397 | 1388 |
Multilingual Too close to call
GPT-5.3 Chat: 50.5 (#119), Muse Glimmer: 50.6 (#117)
| Benchmark | GPT-5.3 Chat | Muse Glimmer |
|---|---|---|
| LMArena Non-English | 1383 | 1384 |
| LMArena Chinese | 1433 | 1412 |
| LMArena Russian | 1400 | 1393 |
| LMArena French | 1398 | — |
| LMArena German | 1384 | — |
| LMArena Japanese | 1351 | — |
| LMArena Korean | 1347 | — |
| LMArena Spanish | 1371 | — |
Instruction Following Too close to call
GPT-5.3 Chat: 73.0 (#124), Muse Glimmer: 72.7 (#134)
| Benchmark | GPT-5.3 Chat | Muse Glimmer |
|---|---|---|
| LMArena Instruction Following | 1378 | 1374 |
Long Context Too close to call
GPT-5.3 Chat: 42.6 (#115), Muse Glimmer: 42.1 (#124)
| Benchmark | GPT-5.3 Chat | Muse Glimmer |
|---|---|---|
| LMArena Longer Query | 1396 | 1381 |
Writing & Preference GPT-5.3 Chat leads
GPT-5.3 Chat: 63.3 (#65), Muse Glimmer: 57.7 (#122)
| Benchmark | GPT-5.3 Chat | Muse Glimmer |
|---|---|---|
| LMArena Text | 1389 | 1389 |
| LMArena Creative Writing | 1356 | 1338 |
| LMArena Multi-Turn | 1413 | 1398 |
| EQ-Bench Creative Writing | 1690 | — |
Frequently asked questions
Is GPT-5.3 Chat better than Muse Glimmer?
GPT-5.3 Chat and Muse Glimmer score almost the same on the Noometry Index (42.1 vs 41.3), so choose on price, context window or the category you care about most.
Is GPT-5.3 Chat or Muse Glimmer better for coding?
GPT-5.3 Chat scores higher on coding benchmarks: 40.8 versus 38.7 in the Noometry coding category.
How many benchmarks do GPT-5.3 Chat and Muse Glimmer share?
12 benchmarks have published results for both models. GPT-5.3 Chat has 18 scored results on Noometry and Muse Glimmer has 13.