# GLM-4.5 vs GPT-5.5 Instant

> GLM-4.5 and GPT-5.5 Instant score almost the same on the Noometry Index (42.0 vs 42.7), so choose on price, context window or the category you care about most.

- Canonical page: https://noometry.com/compare/glm-4-5-vs-gpt-5-5-instant
- Last updated: 2026-10-12
- Shared benchmarks: 17

## Summary

- They share 17 benchmarks with published results for both. GLM-4.5 scores higher in 3 categories and GPT-5.5 Instant in 5 categories; 6 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where GPT-5.5 Instant leads 48.9 to 35.9.
- GLM-4.5 has downloadable open weights; the other is API-only.

## Snapshot

| | GLM-4.5 | GPT-5.5 Instant |
|---|---|---|
| Provider | Z.ai (Zhipu) | OpenAI |
| Noometry Index | 42.0 | 42.7 |
| Rank | 122 | 110 |
| Context | 131K | — |
| Input $/M | $0.60 | — |
| Output $/M | $2.20 | — |
| Weights | Open | Proprietary |

## Coding

- GLM-4.5: 41.4 (#125)
- GPT-5.5 Instant: 44.3 (#74)

| Benchmark | GLM-4.5 | GPT-5.5 Instant |
|---|---|---|
| LMArena Coding | 1434 | 1433 |
| SWE-bench Verified (bash only) | 54.2% | — |
| SciCode | — | 48.6% |
| WeirdML | 40.6% | — |
| ALE-Bench | 344.82 | — |
| AlgoTune | 1.52 | — |

## Reasoning

- GLM-4.5: 28.6 (#100)
- GPT-5.5 Instant: 24.9 (#155)

| Benchmark | GLM-4.5 | GPT-5.5 Instant |
|---|---|---|
| LMArena Hard Prompts | 1429 | 1426 |
| Kagi LLM Benchmark | 57.9% | — |
| CritPt | — | 0% |
| Chess Puzzles | — | 12% |
| Epoch Capabilities Index | — | 142.52 |

## Math

- GLM-4.5: 39.0 (#116)
- GPT-5.5 Instant: 26.5 (#259)

| Benchmark | GLM-4.5 | GPT-5.5 Instant |
|---|---|---|
| LMArena Math | 1427 | 1420 |
| FrontierMath (Tiers 1-3) | — | 26.3% |
| FrontierMath Tier 4 | — | 2.4% |
| OTIS Mock AIME 2024-2025 | — | 68.1% |

## Knowledge

- GLM-4.5: 35.9 (#179)
- GPT-5.5 Instant: 48.9 (#74)

| Benchmark | GLM-4.5 | GPT-5.5 Instant |
|---|---|---|
| LMArena Expert | 1433 | 1409 |
| GPQA Diamond | — | 82.5% |
| Humanity's Last Exam | 8.3% | — |
| Confabulations | 11.3% | — |

## Multimodal

- GLM-4.5: —
- GPT-5.5 Instant: 40.0 (#52)

| Benchmark | GLM-4.5 | GPT-5.5 Instant |
|---|---|---|
| LMArena Vision | — | 1250 |
| LMArena Document | — | 1403 |

## Multilingual

- GLM-4.5: 52.8 (#77)
- GPT-5.5 Instant: 52.8 (#80)

| Benchmark | GLM-4.5 | GPT-5.5 Instant |
|---|---|---|
| LMArena Non-English | 1417 | 1417 |
| LMArena Chinese | 1465 | 1456 |
| LMArena French | 1418 | 1428 |
| LMArena German | 1407 | 1411 |
| LMArena Japanese | 1415 | 1408 |
| LMArena Korean | 1380 | 1392 |
| LMArena Russian | 1414 | 1431 |
| LMArena Spanish | 1454 | 1429 |

## Instruction Following

- GLM-4.5: 74.1 (#104)
- GPT-5.5 Instant: 74.2 (#100)

| Benchmark | GLM-4.5 | GPT-5.5 Instant |
|---|---|---|
| LMArena Instruction Following | 1404 | 1406 |

## Long Context

- GLM-4.5: 38.2 (#201)
- GPT-5.5 Instant: 43.4 (#96)

| Benchmark | GLM-4.5 | GPT-5.5 Instant |
|---|---|---|
| LMArena Longer Query | 1412 | 1422 |
| Fiction.LiveBench | 58.3% | — |

## Writing & Preference

- GLM-4.5: 57.5 (#127)
- GPT-5.5 Instant: 61.8 (#85)

| Benchmark | GLM-4.5 | GPT-5.5 Instant |
|---|---|---|
| LMArena Text | 1430 | 1419 |
| LMArena Creative Writing | 1395 | 1419 |
| LMArena Multi-Turn | 1415 | 1433 |
| Short-Story Creative Writing | 73.4% | — |
| EQ-Bench Creative Writing | 1343 | — |

## FAQ

### Is GLM-4.5 better than GPT-5.5 Instant?

GLM-4.5 and GPT-5.5 Instant score almost the same on the Noometry Index (42.0 vs 42.7), so choose on price, context window or the category you care about most.

### Is GLM-4.5 or GPT-5.5 Instant better for coding?

GPT-5.5 Instant scores higher on coding benchmarks: 44.3 versus 41.4 in the Noometry coding category.

### How many benchmarks do GLM-4.5 and GPT-5.5 Instant share?

17 benchmarks have published results for both models. GLM-4.5 has 27 scored results on Noometry and GPT-5.5 Instant has 27.