Model comparison
Gemini 3.5 Flash vs GLM-5.1
Gemini 3.5 Flash is the stronger model overall, scoring 54.2 to 47.8 on the Noometry Index. GLM-5.1 costs 1.6× less per token, which makes it the better buy when Gemini 3.5 Flash's lead doesn't matter for your workload.
Last verified . 38 shared benchmarks.
GoogleSummary
- They share 38 benchmarks with published results for both. Gemini 3.5 Flash scores higher in 7 categories and GLM-5.1 in 2 categories; 5 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Gemini 3.5 Flash leads 62.8 to 39.1.
- The biggest single-benchmark swing is SimpleQA Verified: 66.2% for Gemini 3.5 Flash and 34% for GLM-5.1.
- GLM-5.1 is cheaper at $1.40 / $4.40 per million input/output tokens, against $1.50 / $9 for Gemini 3.5 Flash.
- Gemini 3.5 Flash accepts more context: 1.05M tokens versus 200K.
- GLM-5.1 has downloadable open weights; the other is API-only.
Side by side
| Gemini 3.5 Flash | GLM-5.1 | |
|---|---|---|
| Provider | Z.ai (Zhipu) | |
| Noometry Index | 54.2 | 47.8 |
| Released | 2026-05-19 | 2026-04-07 |
| Weights | Proprietary | Open |
| Context window | 1.05M | 200K |
| Max output | 66K | 131K |
| Input $ / M tokens | $1.50 | $1.40 |
| Output $ / M tokens | $9 | $4.40 |
| Results tracked | 54 | 41 |
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Category by category
Coding Too close to call
Gemini 3.5 Flash: 49.4 (#49), GLM-5.1: 48.7 (#55)
| Benchmark | Gemini 3.5 Flash | GLM-5.1 |
|---|---|---|
| SWE-bench Verified | 79.3% | 74.2% |
| LMArena WebDev | 1499 | 1508 |
| SciCode | 53.1% | 43.8% |
| WeirdML | 62.6% | 57.1% |
| LMArena Coding | 1492 | 1485 |
| ALE-Bench | 911.02 | 887.1 |
| DeepSWE | 37.4% | — |
Agentic & Tool Use Too close to call
Gemini 3.5 Flash: 24.7 (#114), GLM-5.1: 24.9 (#113)
| Benchmark | Gemini 3.5 Flash | GLM-5.1 |
|---|---|---|
| APEX-Agents | 27.5% | 40.9% |
| GBAEval | 6.7% | 0% |
| Vending-Bench 2 | 5,396 | 5,634 |
| ExploitBench | — | 18.1% |
| GDP.pdf | 14% | — |
Reasoning Gemini 3.5 Flash leads
Gemini 3.5 Flash: 62.8 (#18), GLM-5.1: 39.1 (#60)
| Benchmark | Gemini 3.5 Flash | GLM-5.1 |
|---|---|---|
| SimpleBench | 76.7% | 55.1% |
| NYT Connections (extended) | 92.6% | 77.7% |
| CritPt | 13.1% | 4.6% |
| Chess Puzzles | 50% | 19% |
| LMArena Hard Prompts | 1488 | 1472 |
| Epoch Capabilities Index | 154.46 | 149.84 |
| ARC-AGI-2 | 72.1% | — |
| ARC-AGI-1 | 92.5% | — |
| EnigmaEval | 25.4% | — |
| Thematic Generalization | — | 69.8% |
| EBR-Bench | 4.8% | — |
| Mystery Game Puzzles | 32% | — |
| DTBench | 94.7% | — |
| LMCA | 47.1% | — |
| Surface Evolver Bench | 58.1% | — |
| ForecastBench | 59 | — |
Math Gemini 3.5 Flash leads
Gemini 3.5 Flash: 60.7 (#36), GLM-5.1: 49.7 (#60)
| Benchmark | Gemini 3.5 Flash | GLM-5.1 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 62.8% | 36.8% |
| MathArena Final-Answer Competitions | 76.3% | 67.1% |
| OTIS Mock AIME 2024-2025 | 95.6% | 93.3% |
| ProofBench | 31% | 22.2% |
| LMArena Math | 1504 | 1473 |
| FrontierMath (Feb 2025 set) | 39% | 33.4% |
| FrontierMath Tier 4 (v1) | 14.6% | 12.5% |
| FrontierMath Tier 4 | 26.8% | — |
Knowledge Gemini 3.5 Flash leads
Gemini 3.5 Flash: 66.3 (#11), GLM-5.1: 54.9 (#50)
| Benchmark | Gemini 3.5 Flash | GLM-5.1 |
|---|---|---|
| GPQA Diamond | 92.8% | 89.9% |
| SimpleQA Verified | 66.2% | 34% |
| LMArena Expert | 1495 | 1476 |
Multimodal Not comparable
Gemini 3.5 Flash: 45.7 (#15), GLM-5.1: —
| Benchmark | Gemini 3.5 Flash | GLM-5.1 |
|---|---|---|
| LMArena Vision | 1310 | — |
| Blueprint-Bench 2 | 33.6% | — |
| LMArena Document | 1463 | — |
Multilingual Gemini 3.5 Flash leads
Gemini 3.5 Flash: 57.0 (#13), GLM-5.1: 55.0 (#36)
| Benchmark | Gemini 3.5 Flash | GLM-5.1 |
|---|---|---|
| LMArena Non-English | 1476 | 1447 |
| LMArena Chinese | 1526 | 1515 |
| LMArena French | 1490 | 1474 |
| LMArena German | 1492 | 1465 |
| LMArena Japanese | 1486 | 1434 |
| LMArena Korean | 1451 | 1418 |
| LMArena Russian | 1493 | 1454 |
| LMArena Spanish | 1480 | 1469 |
Instruction Following Too close to call
Gemini 3.5 Flash: 77.0 (#30), GLM-5.1: 76.3 (#42)
| Benchmark | Gemini 3.5 Flash | GLM-5.1 |
|---|---|---|
| LMArena Instruction Following | 1467 | 1451 |
Long Context Too close to call
Gemini 3.5 Flash: 45.4 (#38), GLM-5.1: 44.9 (#53)
| Benchmark | Gemini 3.5 Flash | GLM-5.1 |
|---|---|---|
| LMArena Longer Query | 1482 | 1466 |
Writing & Preference GLM-5.1 leads
Gemini 3.5 Flash: 65.5 (#47), GLM-5.1: 66.9 (#31)
| Benchmark | Gemini 3.5 Flash | GLM-5.1 |
|---|---|---|
| LMArena Text | 1482 | 1461 |
| LMArena Creative Writing | 1470 | 1453 |
| LMArena Multi-Turn | 1481 | 1472 |
| EQ-Bench Creative Writing | — | 1592 |
| EQ-Bench 4 | 1087 | — |
Frequently asked questions
Is Gemini 3.5 Flash better than GLM-5.1?
Gemini 3.5 Flash is the stronger model overall, scoring 54.2 to 47.8 on the Noometry Index. GLM-5.1 costs 1.6× less per token, which makes it the better buy when Gemini 3.5 Flash's lead doesn't matter for your workload.
Which is cheaper, Gemini 3.5 Flash or GLM-5.1?
GLM-5.1 is cheaper. It lists at $1.40 per million input tokens and $4.40 per million output tokens; Gemini 3.5 Flash lists at $1.50 and $9.
Is Gemini 3.5 Flash or GLM-5.1 better for coding?
They score almost the same on coding (49.4 vs 48.7); test both on your own repository before choosing.
Which has the bigger context window?
Gemini 3.5 Flash does, with 1.05M tokens against 200K.
How many benchmarks do Gemini 3.5 Flash and GLM-5.1 share?
38 benchmarks have published results for both models. Gemini 3.5 Flash has 54 scored results on Noometry and GLM-5.1 has 41.