Gemini 3.1 Pro Preview vs GLM 5.3 Flash
Updated October 21, 2026. 87 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
vs boards won of 87 shared, 1 tied
Decision reading
Pick GLM 5.3 Flash for coding: it scores 71.0 on the Vibe Coding Index against 35.3 for Gemini 3.1 Pro Preview.
Pick Gemini 3.1 Pro Preview when what matters is LiveCodeBench (Vals AI) or Vibe Code Bench (Vals AI), where it leads.
Model AGemini 3.1 Pro PreviewGoogle35.3/1001 independent benchmark$0.99 per solved taskModel BGLM 5.3 FlashZ.ai71.0/1002 independent benchmarks$0.02 per solved task
- Shared results
- 87
- Gemini 3.1 Pro Preview only
- 44
- GLM 5.3 Flash only
- 15
- Like-for-like categories
- 8 of 9
Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, four public coding benchmarks
GLM 5.3 Flash
GLM 5.3 Flash scores 71.0 against 35.3.
1 and 2 benchmarks behind the scores
Intelligence
AA Intelligence Index
GLM 5.3 Flash
GLM 5.3 Flash leads, 41.8 against 29.7.
Same board, both measured
Agentic work
AA Agentic Index
GLM 5.3 Flash
GLM 5.3 Flash leads, 50.9 against 8.2.
Same board, both measured
Reasoning
GPQA Diamond
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview leads, 95.5% against 86.4%.
Same board, both measured
Math
AIME
No call
Only Gemini 3.1 Pro Preview has a AIME result, 98.1%.
Directional only
Knowledge
MMLU Pro
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview leads, 91.0% against 86.1%.
Same board, both measured
Web design
Design Arena: websites
GLM 5.3 Flash
GLM 5.3 Flash leads, 1272 against 1234.
Same board, both measured
General
Vals Index
No call
Only GLM 5.3 Flash has a Vals Index result, 50.9%.
Directional only
Long documents
Listed context window
No call
Both take 1.05M tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GLM 5.3 Flash
Gemini 3.1 Pro Preview $0.0080, GLM 5.3 Flash $0.0004 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
GLM 5.3 Flash
Gemini 3.1 Pro Preview $0.99, GLM 5.3 Flash $0.02.
Published attempt cost and pass rate
At a glance
- Coding index
- Gemini 3.1 Pro Preview 35.3 from 1 benchmark, GLM 5.3 Flash 71.0 from 2 benchmarks.
- Widest category
- Agentic work, 15.9 points apart on average over 8 shared benchmarks.
- Widest single gap
- AA Agentic Index: Gemini 3.1 Pro Preview 8.2 against GLM 5.3 Flash 50.9, 42.7 points apart on a 0 to 100 scale.
- Output price
- Gemini 3.1 Pro Preview $12.00 against GLM 5.3 Flash $0.50 per million output tokens, 24.0x apart.
- Context window
- Both take 1.05M tokens.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | Gemini 3.1 Pro Preview | Bars | GLM 5.3 Flash | Ties |
|---|---|---|---|---|
| Coding | 5 | 12 | 1 tie | |
| Intelligence | 0 | 1 | ||
| Agentic work | 0 | 8 | ||
| Reasoning | 9 | 5 | ||
| Math | 4 | 2 | ||
| Knowledge | 5 | 2 | ||
| Web design | 2 | 6 | ||
| General | 20 | 5 | ||
| All shared boards | 45 | 41 | 1 tie |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index512
| Benchmark | Gemini 3.1 Pro Preview | GLM 5.3 Flash | Leader |
|---|---|---|---|
| LiveBench coding | Not measured | 80.6% | Only GLM 5.3 Flash measured |
| LMArena WebDev | 1447 | 1607 | GLM 5.3 Flash |
| AA Coding Index | 68.8 | 71.5 | GLM 5.3 Flash |
| LiveCodeBench (Vals AI) | 88.5% | 80.5% | Gemini 3.1 Pro Preview |
| SWE-bench Verified (Vals AI) | 78.8% | 92.0% | GLM 5.3 Flash |
| Terminal-Bench 4 (Vals AI) | 2.5% | 37.4% | GLM 5.3 Flash |
| Vibe Code Bench (Vals AI) | 32.0% | 30.8% | Gemini 3.1 Pro Preview |
| Code migration (Vals AI) | 17.3% | 20.5% | GLM 5.3 Flash |
| ProgramBench (Vals AI) | 0.0% | 0.0% | Tie |
| IOI (Vals AI) | 51.8% | 52.5% | GLM 5.3 Flash |
| Terminal-Bench 2.1 (Vals AI) | 70.8% | 62.9% | Gemini 3.1 Pro Preview |
| Vibe Code Bench 1-100 (Vals AI) | 6.7% | 16.0% | GLM 5.3 Flash |
| SkillsBench (Vals AI) | Not measured | 40.2% | Only GLM 5.3 Flash measured |
| CyberBench (Vals AI) | Not measured | 67.9% | Only GLM 5.3 Flash measured |
| SciCode | 58.7% | 51.6% | Gemini 3.1 Pro Preview |
| Terminal-Bench Hard (Artificial Analysis run) | 53.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Terminal-Bench | 80.2% | Not measured | Only Gemini 3.1 Pro Preview measured |
| FrontierCode | Not measured | 31.8% | Only GLM 5.3 Flash measured |
| FrontierSWE | Not measured | 18.1% | Only GLM 5.3 Flash measured |
| GSO-Bench | 22.6% | Not measured | Only Gemini 3.1 Pro Preview measured |
| WeirdML | 72.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| MirrorCode | 8.9% | Not measured | Only Gemini 3.1 Pro Preview measured |
| ALE-Bench | 1160.6 | 303.6 | Gemini 3.1 Pro Preview |
| LMArena Text: coding | 1484 | 1507 | GLM 5.3 Flash |
| LMArena Text: software and IT | 1487 | 1500 | GLM 5.3 Flash |
| LMArena WebDev: React | 1438 | 1624 | GLM 5.3 Flash |
| LMArena WebDev: HTML | 1490 | 1577 | GLM 5.3 Flash |
| LMArena WebDev: from an image | 1481 | 1578 | GLM 5.3 Flash |
| Neither model has a result on the other 10 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Gemini 3.1 Pro Preview | GLM 5.3 Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | 29.7 | 41.8 | GLM 5.3 Flash |
| Epoch Capabilities Index | Not measured | 153.1 | Only GLM 5.3 Flash measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index08
| Benchmark | Gemini 3.1 Pro Preview | GLM 5.3 Flash | Leader |
|---|---|---|---|
| AA Agentic Index | 8.2 | 50.9 | GLM 5.3 Flash |
| Design Arena: agents building web apps | 1125 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building full-stack apps | 1068 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building mobile apps | 1094 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building Android apps | 1055 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building Godot games | 1236 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building games | 1114 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: HTML slides | 1153 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: PowerPoint slides | 1064 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LiveBench research | Not measured | 70.1% | Only GLM 5.3 Flash measured |
| LiveBench browser | Not measured | 84.0% | Only GLM 5.3 Flash measured |
| LiveBench long agentic | Not measured | 28.4% | Only GLM 5.3 Flash measured |
| SREBench (Vals AI) | 0.0% | 0.8% | GLM 5.3 Flash |
| Finance Agent (Vals AI) | 43.0% | 57.9% | GLM 5.3 Flash |
| Tax Agent Bench (Vals AI) | 9.3% | 31.6% | GLM 5.3 Flash |
| Legal Research Bench (Vals AI) | 20.7% | 45.2% | GLM 5.3 Flash |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 10.4% | Only GLM 5.3 Flash measured |
| Excel Modeling Benchmark (Vals AI) | 52.6% | 55.9% | GLM 5.3 Flash |
| BioMysteryBench (Vals AI) | 60.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Terminal-Bench-Science (Vals AI) | 1.4% | 2.9% | GLM 5.3 Flash |
| Vals Science Index | 27.4% | Not measured | Only Gemini 3.1 Pro Preview measured |
| τ²-Bench Telecom | 95.6% | Not measured | Only Gemini 3.1 Pro Preview measured |
| APEX-Agents | 35.1% | 52.8% | GLM 5.3 Flash |
| METR time horizons | 77.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| BALROG | 57.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| DeepResearch Bench | 47.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| PostTrainBench | 22.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Vending-Bench 2 | $911 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 11 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index95
| Benchmark | Gemini 3.1 Pro Preview | GLM 5.3 Flash | Leader |
|---|---|---|---|
| GPQA Diamond | 95.5% | 86.4% | Gemini 3.1 Pro Preview |
| LiveBench reasoning | Not measured | 77.6% | Only GLM 5.3 Flash measured |
| MysteryMechanism (Vals AI) | 20.7% | Not measured | Only Gemini 3.1 Pro Preview measured |
| MMMU Pro (Vals AI) | 88.2% | 86.0% | Gemini 3.1 Pro Preview |
| GPQA Diamond (Artificial Analysis run) | 94.1% | 91.2% | Gemini 3.1 Pro Preview |
| Humanity's Last Exam (Artificial Analysis run) | 47.0% | 39.9% | Gemini 3.1 Pro Preview |
| GPQA Diamond (Epoch AI run) | 94.4% | 90.2% | Gemini 3.1 Pro Preview |
| ARC-AGI | 98.0% | 91.0% | Gemini 3.1 Pro Preview |
| ARC-AGI-2 | 77.1% | 65.8% | Gemini 3.1 Pro Preview |
| SimpleBench | 79.6% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Chess puzzles | 51.0% | 21.0% | Gemini 3.1 Pro Preview |
| Mystery game puzzles | 34.0% | 8.0% | Gemini 3.1 Pro Preview |
| EBR-bench | 14.3% | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: hard prompts | 1485 | 1490 | GLM 5.3 Flash |
| LMArena Text: expert | 1483 | 1511 | GLM 5.3 Flash |
| LMArena Text: hard prompts in English | 1480 | 1488 | GLM 5.3 Flash |
| LMArena Vision: diagrams | 1311 | 1317 | GLM 5.3 Flash |
| LMArena Vision: homework | 1316 | 1318 | GLM 5.3 Flash |
| Neither model has a result on the other 3 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index42
| Benchmark | Gemini 3.1 Pro Preview | GLM 5.3 Flash | Leader |
|---|---|---|---|
| AIME | 98.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| OTIS Mock AIME | 95.6% | 93.9% | Gemini 3.1 Pro Preview |
| FrontierMath, tiers 1 to 3 | 59.6% | 55.8% | Gemini 3.1 Pro Preview |
| FrontierMath, tier 4 | 26.8% | 17.1% | Gemini 3.1 Pro Preview |
| ProofBench | 26.0% | 21.0% | Gemini 3.1 Pro Preview |
| LMArena Text: math | 1486 | 1503 | GLM 5.3 Flash |
| LMArena Text: mathematical work | 1478 | 1497 | GLM 5.3 Flash |
| Neither model has a result on the other 6 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index52
| Benchmark | Gemini 3.1 Pro Preview | GLM 5.3 Flash | Leader |
|---|---|---|---|
| MMLU Pro | 91.0% | 86.1% | Gemini 3.1 Pro Preview |
| LegalBench (Vals AI) | 87.4% | 83.9% | Gemini 3.1 Pro Preview |
| CaseLaw (Vals AI) | 64.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| CorpFin (Vals AI) | 64.5% | Not measured | Only Gemini 3.1 Pro Preview measured |
| TaxEval (Vals AI) | 72.9% | 75.6% | GLM 5.3 Flash |
| MortgageTax (Vals AI) | 69.4% | Not measured | Only Gemini 3.1 Pro Preview measured |
| MedQA (Vals AI) | 96.4% | Not measured | Only Gemini 3.1 Pro Preview measured |
| MedCode (Vals AI) | 59.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| SimpleQA Verified | 73.5% | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: science | 1497 | 1484 | Gemini 3.1 Pro Preview |
| LMArena Text: medicine and healthcare | 1486 | 1475 | Gemini 3.1 Pro Preview |
| LMArena Text: legal and government | 1487 | 1473 | Gemini 3.1 Pro Preview |
| LMArena Text: business and finance | 1459 | 1460 | GLM 5.3 Flash |
| Neither model has a result on the other 4 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index26
| Benchmark | Gemini 3.1 Pro Preview | GLM 5.3 Flash | Leader |
|---|---|---|---|
| Design Arena: websites | 1234 | 1272 | GLM 5.3 Flash |
| Design Arena: UI components | 1226 | 1316 | GLM 5.3 Flash |
| Design Arena: game dev | 1203 | 1279 | GLM 5.3 Flash |
| Design Arena: data viz | 1209 | 1262 | GLM 5.3 Flash |
| Design Arena: 3D | 1234 | 1316 | GLM 5.3 Flash |
| Design Arena: all code categories | 1231 | 1282 | GLM 5.3 Flash |
| Design Arena: SVG | 1285 | 1284 | Gemini 3.1 Pro Preview |
| Design Arena: ASCII art | 1270 | 1269 | Gemini 3.1 Pro Preview |
| LiveBench design | Not measured | 77.2% | Only GLM 5.3 Flash measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index205
| Benchmark | Gemini 3.1 Pro Preview | GLM 5.3 Flash | Leader |
|---|---|---|---|
| Vals Index | Not measured | 50.9% | Only GLM 5.3 Flash measured |
| LiveBench data analysis | Not measured | 76.4% | Only GLM 5.3 Flash measured |
| Public Benefits Bench (Vals AI) | 53.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| SAGE (Vals AI) | 48.7% | Not measured | Only Gemini 3.1 Pro Preview measured |
| MedScribe (Vals AI) | 76.1% | 88.9% | GLM 5.3 Flash |
| Vals Multimodal Index | 56.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| IFBench | 77.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Long context reasoning (AA-LCR) | 82.0% | 80.0% | Gemini 3.1 Pro Preview |
| DTBench | 97.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMCA | 53.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| CL-bench | 20.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Surface Evolver Bench | Not measured | 52.5% | Only GLM 5.3 Flash measured |
| Furniture assembly | 26.7% | Not measured | Only Gemini 3.1 Pro Preview measured |
| ExploitBench | 26.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| CL-bench Life | 16.9% | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text | 1480 | 1471 | Gemini 3.1 Pro Preview |
| LMArena Text: instruction following | 1466 | 1478 | GLM 5.3 Flash |
| LMArena Text: creative writing | 1482 | 1441 | Gemini 3.1 Pro Preview |
| LMArena Vision | 1296 | 1294 | Gemini 3.1 Pro Preview |
| LMArena Text: English | 1478 | 1474 | Gemini 3.1 Pro Preview |
| LMArena Text: non-English | 1476 | 1462 | Gemini 3.1 Pro Preview |
| LMArena Text: Chinese | 1527 | 1531 | GLM 5.3 Flash |
| LMArena Text: German | 1490 | 1462 | Gemini 3.1 Pro Preview |
| LMArena Text: Japanese | 1491 | 1444 | Gemini 3.1 Pro Preview |
| LMArena Text: Korean | 1455 | 1436 | Gemini 3.1 Pro Preview |
| LMArena Text: French | 1487 | 1491 | GLM 5.3 Flash |
| LMArena Text: Spanish | 1481 | 1475 | Gemini 3.1 Pro Preview |
| LMArena Text: Russian | 1497 | 1465 | Gemini 3.1 Pro Preview |
| LMArena Text: Polish | 1498 | 1450 | Gemini 3.1 Pro Preview |
| LMArena Text: multi-turn | 1487 | 1469 | Gemini 3.1 Pro Preview |
| LMArena Text: longer queries | 1482 | 1481 | Gemini 3.1 Pro Preview |
| LMArena Text: writing and language | 1481 | 1455 | Gemini 3.1 Pro Preview |
| LMArena Text: entertainment and media | 1465 | 1440 | Gemini 3.1 Pro Preview |
| LMArena Vision: English | 1287 | 1295 | GLM 5.3 Flash |
| LMArena Vision: Chinese | 1364 | 1363 | Gemini 3.1 Pro Preview |
| LMArena Vision: reading text | 1304 | 1299 | Gemini 3.1 Pro Preview |
| LMArena Vision: humor | 1322 | 1279 | Gemini 3.1 Pro Preview |
| LMArena Vision: captioning | 1345 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: recognizing things | 1330 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: creative writing | 1324 | 1270 | Gemini 3.1 Pro Preview |
| LMArena Document | 1444 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 5 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemini 3.1 Pro Preview | GLM 5.3 Flash | Leader |
|---|---|---|---|
| Neither model has a result on 5 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
Gemini 3.1 Pro Preview$0.0080Fits in one request
GLM 5.3 Flash$0.0004Fits in one request
GLM 5.3 Flash costs less
Repository review
50K input + 3K output tokens
Gemini 3.1 Pro Preview$0.136Fits in one request
GLM 5.3 Flash$0.0090Fits in one request
GLM 5.3 Flash costs less
Agent loop
200K input + 10K output tokens
Gemini 3.1 Pro Preview$0.520Fits in one request
GLM 5.3 Flash$0.035Fits in one request
GLM 5.3 Flash costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | Google Gemini 3.1 Pro Preview | Z.ai GLM 5.3 Flash |
|---|---|---|
| Maker | Z.ai | |
| Weights | No public weights listed | Open weights |
| Released | February 19, 2026 | August 26, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $2.00 | $0.15 |
| Output $/Mtok | $12.00 | $0.50 |
| Coding index | 35.3 | 71.0 |
| Independent measurements behind it | 1 | 2 |
| Cost per solved task | $0.99 | $0.02 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3.1 Pro Preview better than GLM 5.3 Flash for coding?
Pick GLM 5.3 Flash for coding: it scores 71.0 on the Vibe Coding Index against 35.3 for Gemini 3.1 Pro Preview. Pick Gemini 3.1 Pro Preview when what matters is LiveCodeBench (Vals AI) or Vibe Code Bench (Vals AI), where it leads.
Which is cheaper, Gemini 3.1 Pro Preview or GLM 5.3 Flash?
Gemini 3.1 Pro Preview costs $2.00 per million input tokens and $12.00 per million output tokens; GLM 5.3 Flash costs $0.15 and $0.50. Per solved SWE-bench Verified task, Gemini 3.1 Pro Preview costs $0.99 and GLM 5.3 Flash $0.02.
Which has the bigger context window, Gemini 3.1 Pro Preview or GLM 5.3 Flash?
Neither: both take 1.05M tokens.
How many benchmarks is the Gemini 3.1 Pro Preview vs GLM 5.3 Flash comparison based on?
87 benchmarks have a result for both models as of October 21, 2026. Gemini 3.1 Pro Preview's coding index rests on 1 independent benchmark and GLM 5.3 Flash's on 2. Where only one model has a result, the page says so instead of naming a winner.