Model comparison
GLM-4.5 vs Grok 4.1 Fast
GLM-4.5 and Grok 4.1 Fast score almost the same on the Noometry Index (42.0 vs 41.4), so choose on price, context window or the category you care about most.
Last verified . 19 shared benchmarks.
Summary
- They share 19 benchmarks with published results for both. GLM-4.5 scores higher in 6 categories and Grok 4.1 Fast in 2 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.1 Fast leads 43.4 to 28.6.
- Grok 4.1 Fast is cheaper at $0.20 / $0.50 per million input/output tokens, against $0.60 / $2.20 for GLM-4.5.
- GLM-4.5 accepts more context: 131K tokens versus 128K.
- GLM-4.5 has downloadable open weights; the other is API-only.
Side by side
| GLM-4.5 | Grok 4.1 Fast | |
|---|---|---|
| Provider | Z.ai (Zhipu) | xAI |
| Noometry Index | 42.0 | 41.4 |
| Released | 2025-07-27 | 2025-06-27 |
| Weights | Open | Proprietary |
| Context window | 131K | 128K |
| Max output | 98K | 30K |
| Input $ / M tokens | $0.60 | $0.20 |
| Output $ / M tokens | $2.20 | $0.50 |
| Results tracked | 27 | 32 |
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Category by category
Coding GLM-4.5 leads
GLM-4.5: 41.4 (#125), Grok 4.1 Fast: 34.1 (#245)
| Benchmark | GLM-4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Coding | 1434 | 1411 |
| ALE-Bench | 344.82 | 394.93 |
| SWE-bench Verified (bash only) | 54.2% | — |
| LMArena WebDev | — | 1242 |
| WeirdML | 40.6% | — |
| AlgoTune | 1.52 | — |
Agentic & Tool Use Not comparable
GLM-4.5: —, Grok 4.1 Fast: 36.3 (#39)
| Benchmark | GLM-4.5 | Grok 4.1 Fast |
|---|---|---|
| Berkeley Function Calling Leaderboard | — | 69.6% |
| τ²-bench Banking | — | 13.1% |
| LMArena Search | — | 1171 |
| Vending-Bench 2 | — | 1,107 |
Reasoning Grok 4.1 Fast leads
GLM-4.5: 28.6 (#100), Grok 4.1 Fast: 43.4 (#49)
| Benchmark | GLM-4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Hard Prompts | 1429 | 1407 |
| SimpleBench | — | 56% |
| Kagi LLM Benchmark | 57.9% | — |
| NYT Connections (extended) | — | 87.4% |
| DTBench | — | 87.7% |
| ForecastBench | — | 61 |
Math GLM-4.5 leads
GLM-4.5: 39.0 (#116), Grok 4.1 Fast: 31.9 (#221)
| Benchmark | GLM-4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Math | 1427 | 1408 |
| MathArena Final-Answer Competitions | — | 60.9% |
| ProofBench | — | 4% |
Knowledge GLM-4.5 leads
GLM-4.5: 35.9 (#179), Grok 4.1 Fast: 33.1 (#207)
| Benchmark | GLM-4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Expert | 1433 | 1399 |
| Humanity's Last Exam | 8.3% | — |
| Confabulations | 11.3% | — |
| Vectara Hallucination Rate | — | 17.8% |
Multimodal Not comparable
GLM-4.5: —, Grok 4.1 Fast: 37.0 (#76)
| Benchmark | GLM-4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Vision | — | 1201 |
Multilingual GLM-4.5 leads
GLM-4.5: 52.8 (#77), Grok 4.1 Fast: 51.0 (#114)
| Benchmark | GLM-4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Non-English | 1417 | 1391 |
| LMArena Chinese | 1465 | 1441 |
| LMArena French | 1418 | 1415 |
| LMArena German | 1407 | 1404 |
| LMArena Japanese | 1415 | 1349 |
| LMArena Korean | 1380 | 1361 |
| LMArena Russian | 1414 | 1387 |
| LMArena Spanish | 1454 | 1413 |
Instruction Following GLM-4.5 leads
GLM-4.5: 74.1 (#104), Grok 4.1 Fast: 72.7 (#133)
| Benchmark | GLM-4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Instruction Following | 1404 | 1376 |
Long Context Grok 4.1 Fast leads
GLM-4.5: 38.2 (#201), Grok 4.1 Fast: 42.4 (#126)
| Benchmark | GLM-4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Longer Query | 1412 | 1390 |
| Fiction.LiveBench | 58.3% | — |
Writing & Preference Too close to call
GLM-4.5: 57.5 (#127), Grok 4.1 Fast: 57.2 (#131)
| Benchmark | GLM-4.5 | Grok 4.1 Fast |
|---|---|---|
| LMArena Text | 1430 | 1408 |
| LMArena Creative Writing | 1395 | 1394 |
| EQ-Bench Creative Writing | 1343 | 1327 |
| LMArena Multi-Turn | 1415 | 1389 |
| Short-Story Creative Writing | 73.4% | — |
Frequently asked questions
Is GLM-4.5 better than Grok 4.1 Fast?
GLM-4.5 and Grok 4.1 Fast score almost the same on the Noometry Index (42.0 vs 41.4), so choose on price, context window or the category you care about most.
Which is cheaper, GLM-4.5 or Grok 4.1 Fast?
Grok 4.1 Fast is cheaper. It lists at $0.20 per million input tokens and $0.50 per million output tokens; GLM-4.5 lists at $0.60 and $2.20.
Is GLM-4.5 or Grok 4.1 Fast better for coding?
GLM-4.5 scores higher on coding benchmarks: 41.4 versus 34.1 in the Noometry coding category.
Which has the bigger context window?
GLM-4.5 does, with 131K tokens against 128K.
How many benchmarks do GLM-4.5 and Grok 4.1 Fast share?
19 benchmarks have published results for both models. GLM-4.5 has 27 scored results on Noometry and Grok 4.1 Fast has 32.