GLM 5.1 vs Qwen3.5-Flash
GLM 5.1 leads Qwen3.5-Flash on coding, 49.2 to 41.1 on the Vibe Coding Index, and Qwen3.5-Flash costs 16.9x less per output token ($0.26 vs $4.40 per million). Updated October 23, 2026; 49 benchmarks have a result for both.
GLM 5.1 or Qwen3.5-Flash: which to pick
Pick GLM 5.1 for coding: it scores 49.2 on the Vibe Coding Index against 41.1 for Qwen3.5-Flash.
Pick Qwen3.5-Flash for output tokens 16.9x cheaper ($0.26 vs $4.40 per million) and a lower cost per solved task ($0.40 against $0.60).
- Shared results
- 49
- GLM 5.1 only
- 42
- Qwen3.5-Flash only
- 6
- Like-for-like categories
- 6 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
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, six public coding benchmarks
GLM 5.1
GLM 5.1 scores 49.2 against 41.1.
3 and 2 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only GLM 5.1 has a AA Intelligence Index result, 26.1.
Directional only
Agentic work
AA Agentic Index
No call
Only GLM 5.1 has a AA Agentic Index result, 23.9.
Directional only
Reasoning
GPQA Diamond
GLM 5.1
GLM 5.1 leads, 84.5% against 82.8%.
Same board, both measured
Math
AIME
Qwen3.5-Flash
Qwen3.5-Flash leads, 92.5% against 91.9%.
Same board, both measured
Knowledge
MMLU Pro
GLM 5.1
GLM 5.1 leads, 86.9% against 84.1%.
Same board, both measured
Web design
Design Arena: websites
No call
Only GLM 5.1 has a Design Arena: websites result, 1290.
Directional only
Long documents
Listed context window
Qwen3.5-Flash
Qwen3.5-Flash takes 1M tokens against 205K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Qwen3.5-Flash
GLM 5.1 $0.0036, Qwen3.5-Flash $0.0002 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Qwen3.5-Flash
GLM 5.1 $0.60, Qwen3.5-Flash $0.40.
Published attempt cost and pass rate
At a glance
- Coding index
- GLM 5.1 49.2 from 3 benchmarks, Qwen3.5-Flash 41.1 from 2 benchmarks.
- Widest category
- Coding, 22.2 points apart on average over 8 shared benchmarks.
- Widest single gap
- LMArena WebDev: React: GLM 5.1 1505 against Qwen3.5-Flash 1229, 45.9 points apart on a 0 to 100 scale.
- Output price
- GLM 5.1 $4.40 against Qwen3.5-Flash $0.26 per million output tokens, 16.9x apart.
- Context window
- GLM 5.1 takes 205K tokens, Qwen3.5-Flash 1M.
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 | GLM 5.1 | Bars | Qwen3.5-Flash | Ties |
|---|---|---|---|---|
| Coding | 7 | 1 | ||
| Intelligence | 1 | 0 | ||
| Reasoning | 6 | 0 | ||
| Math | 4 | 1 | ||
| Knowledge | 9 | 2 | ||
| General | 18 | 0 | ||
| All shared boards | 45 | 4 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index71
| Benchmark | GLM 5.1 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| LMArena WebDev | 1508 | 1244 | GLM 5.1 |
| AA Coding Index | 55.8 | Not measured | Only GLM 5.1 measured |
| LiveCodeBench (Vals AI) | 81.4% | 83.3% | Qwen3.5-Flash |
| SWE-bench Verified (Vals AI) | 76.4% | 64.4% | GLM 5.1 |
| Vibe Code Bench (Vals AI) | 31.5% | Not measured | Only GLM 5.1 measured |
| Code migration (Vals AI) | 25.8% | Not measured | Only GLM 5.1 measured |
| ProgramBench (Vals AI) | 0.0% | Not measured | Only GLM 5.1 measured |
| Terminal-Bench 2.1 (Vals AI) | 56.9% | Not measured | Only GLM 5.1 measured |
| SciCode | 44.8% | Not measured | Only GLM 5.1 measured |
| Terminal-Bench Hard (Artificial Analysis run) | 43.2% | Not measured | Only GLM 5.1 measured |
| WeirdML | 57.1% | Not measured | Only GLM 5.1 measured |
| ALE-Bench | 887.1 | 265.9 | GLM 5.1 |
| LMArena Text: coding | 1486 | 1412 | GLM 5.1 |
| LMArena Text: software and IT | 1484 | 1416 | GLM 5.1 |
| LMArena WebDev: React | 1505 | 1229 | GLM 5.1 |
| LMArena WebDev: HTML | 1508 | 1291 | GLM 5.1 |
| Neither model has a result on the other 27 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GLM 5.1 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | 26.1 | Not measured | Only GLM 5.1 measured |
| Epoch Capabilities Index | 149.8 | 143.5 | GLM 5.1 |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index16 boards, none shared
| Benchmark | GLM 5.1 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| AA Agentic Index | 23.9 | Not measured | Only GLM 5.1 measured |
| Design Arena: agents building web apps | 1175 | Not measured | Only GLM 5.1 measured |
| Design Arena: agents building full-stack apps | 1167 | Not measured | Only GLM 5.1 measured |
| Design Arena: agents building mobile apps | 1161 | Not measured | Only GLM 5.1 measured |
| Design Arena: agents building Android apps | 1184 | Not measured | Only GLM 5.1 measured |
| Design Arena: agents building Godot games | 1053 | Not measured | Only GLM 5.1 measured |
| Design Arena: agents building games | 1164 | Not measured | Only GLM 5.1 measured |
| Design Arena: HTML slides | 1076 | Not measured | Only GLM 5.1 measured |
| Design Arena: PowerPoint slides | 1152 | Not measured | Only GLM 5.1 measured |
| Design Arena: spreadsheets | 1315 | Not measured | Only GLM 5.1 measured |
| Finance Agent (Vals AI) | 44.8% | Not measured | Only GLM 5.1 measured |
| Legal Research Bench (Vals AI) | 27.9% | Not measured | Only GLM 5.1 measured |
| τ²-Bench Telecom | 97.7% | Not measured | Only GLM 5.1 measured |
| APEX-Agents | 40.9% | Not measured | Only GLM 5.1 measured |
| Vending-Bench 2 | $5,634 | Not measured | Only GLM 5.1 measured |
| MCP Atlas | 75.6% | Not measured | Only GLM 5.1 measured |
| Neither model has a result on the other 26 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | GLM 5.1 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| GPQA Diamond | 84.5% | 82.8% | GLM 5.1 |
| MMMU Pro (Vals AI) | Not measured | 81.9% | Only Qwen3.5-Flash measured |
| GPQA Diamond (Artificial Analysis run) | 86.8% | Not measured | Only GLM 5.1 measured |
| Humanity's Last Exam (Artificial Analysis run) | 30.1% | Not measured | Only GLM 5.1 measured |
| GPQA Diamond (Epoch AI run) | 89.9% | 82.3% | GLM 5.1 |
| SimpleBench | 55.1% | Not measured | Only GLM 5.1 measured |
| Chess puzzles | 20.0% | 14.0% | GLM 5.1 |
| Mystery game puzzles | Not measured | 20.0% | Only Qwen3.5-Flash measured |
| LMArena Text: hard prompts | 1473 | 1403 | GLM 5.1 |
| LMArena Text: expert | 1478 | 1407 | GLM 5.1 |
| LMArena Text: hard prompts in English | 1482 | 1409 | GLM 5.1 |
| Neither model has a result on the other 12 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index41
| Benchmark | GLM 5.1 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| AIME | 91.9% | 92.5% | Qwen3.5-Flash |
| OTIS Mock AIME | 93.3% | 84.4% | GLM 5.1 |
| FrontierMath, tiers 1 to 3 | 36.8% | 18.2% | GLM 5.1 |
| ProofBench | 22.2% | Not measured | Only GLM 5.1 measured |
| LMArena Text: math | 1474 | 1407 | GLM 5.1 |
| LMArena Text: mathematical work | 1471 | 1413 | GLM 5.1 |
| MathArena | 20.1% | Not measured | Only GLM 5.1 measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index92
| Benchmark | GLM 5.1 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| MMLU Pro | 86.9% | 84.1% | GLM 5.1 |
| LegalBench (Vals AI) | 84.4% | 84.3% | GLM 5.1 |
| CaseLaw (Vals AI) | 51.5% | 56.0% | Qwen3.5-Flash |
| CorpFin (Vals AI) | 64.5% | 63.6% | GLM 5.1 |
| TaxEval (Vals AI) | 71.2% | 72.2% | Qwen3.5-Flash |
| MortgageTax (Vals AI) | Not measured | 67.4% | Only Qwen3.5-Flash measured |
| MedCode (Vals AI) | 41.6% | 33.0% | GLM 5.1 |
| SimpleQA Verified | 34.0% | 20.3% | GLM 5.1 |
| LMArena Text: science | 1478 | 1415 | GLM 5.1 |
| LMArena Text: medicine and healthcare | 1473 | 1407 | GLM 5.1 |
| LMArena Text: legal and government | 1465 | 1397 | GLM 5.1 |
| LMArena Text: business and finance | 1452 | 1394 | GLM 5.1 |
| Neither model has a result on the other 8 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | GLM 5.1 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| Design Arena: websites | 1290 | Not measured | Only GLM 5.1 measured |
| Design Arena: UI components | 1292 | Not measured | Only GLM 5.1 measured |
| Design Arena: game dev | 1264 | Not measured | Only GLM 5.1 measured |
| Design Arena: data viz | 1366 | Not measured | Only GLM 5.1 measured |
| Design Arena: 3D | 1336 | Not measured | Only GLM 5.1 measured |
| Design Arena: all code categories | 1268 | Not measured | Only GLM 5.1 measured |
| Design Arena: SVG | 1218 | Not measured | Only GLM 5.1 measured |
| Design Arena: ASCII art | 1141 | Not measured | Only GLM 5.1 measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index180
| Benchmark | GLM 5.1 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| Public Benefits Bench (Vals AI) | 61.8% | Not measured | Only GLM 5.1 measured |
| SAGE (Vals AI) | Not measured | 42.5% | Only Qwen3.5-Flash measured |
| MedScribe (Vals AI) | 72.3% | 70.6% | GLM 5.1 |
| IFBench | 76.3% | Not measured | Only GLM 5.1 measured |
| Long context reasoning (AA-LCR) | 73.7% | Not measured | Only GLM 5.1 measured |
| DTBench | Not measured | 82.9% | Only Qwen3.5-Flash measured |
| LMCA | Not measured | 29.1% | Only Qwen3.5-Flash measured |
| ExploitBench | 18.1% | Not measured | Only GLM 5.1 measured |
| LMArena Text | 1463 | 1397 | GLM 5.1 |
| LMArena Text: instruction following | 1452 | 1375 | GLM 5.1 |
| LMArena Text: creative writing | 1453 | 1343 | GLM 5.1 |
| LMArena Text: English | 1475 | 1404 | GLM 5.1 |
| LMArena Text: non-English | 1449 | 1385 | GLM 5.1 |
| LMArena Text: Chinese | 1514 | 1446 | GLM 5.1 |
| LMArena Text: German | 1467 | 1391 | GLM 5.1 |
| LMArena Text: Japanese | 1435 | 1369 | GLM 5.1 |
| LMArena Text: Korean | 1424 | 1344 | GLM 5.1 |
| LMArena Text: French | 1471 | 1413 | GLM 5.1 |
| LMArena Text: Spanish | 1469 | 1399 | GLM 5.1 |
| LMArena Text: Russian | 1455 | 1380 | GLM 5.1 |
| LMArena Text: Polish | 1452 | 1376 | GLM 5.1 |
| LMArena Text: multi-turn | 1472 | 1393 | GLM 5.1 |
| LMArena Text: longer queries | 1467 | 1392 | GLM 5.1 |
| LMArena Text: writing and language | 1455 | 1369 | GLM 5.1 |
| LMArena Text: entertainment and media | 1442 | 1347 | GLM 5.1 |
| Neither model has a result on the other 23 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GLM 5.1 | Qwen3.5-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
Qwen3.5-Flash costs less
Repository review
50K input + 3K output tokens
Qwen3.5-Flash costs less
Agent loop
200K input + 10K output tokens
Qwen3.5-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 | Z.ai GLM 5.1 | Qwen3.5-Flash |
|---|---|---|
| Maker | Z.ai | Qwen |
| Weights | Open weights | No public weights listed |
| Released | April 7, 2026 | February 25, 2026 |
| Context window | 205K | 1M |
| Input $/Mtok | $1.40 | $0.065 |
| Output $/Mtok | $4.40 | $0.26 |
| Coding index | 49.2 | 41.1 |
| Independent measurements behind it | 3 | 2 |
| Cost per solved task | $0.60 | $0.40 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GLM 5.1 better than Qwen3.5-Flash for coding?
Pick GLM 5.1 for coding: it scores 49.2 on the Vibe Coding Index against 41.1 for Qwen3.5-Flash. Pick Qwen3.5-Flash for output tokens 16.9x cheaper ($0.26 vs $4.40 per million) and a lower cost per solved task ($0.40 against $0.60).
Which is cheaper, GLM 5.1 or Qwen3.5-Flash?
GLM 5.1 costs $1.40 per million input tokens and $4.40 per million output tokens; Qwen3.5-Flash costs $0.065 and $0.26. Per solved SWE-bench Verified task, GLM 5.1 costs $0.60 and Qwen3.5-Flash $0.40.
Which has the bigger context window, GLM 5.1 or Qwen3.5-Flash?
Qwen3.5-Flash, with 1M tokens against 205K.
How many benchmarks is the GLM 5.1 vs Qwen3.5-Flash comparison based on?
49 benchmarks have a result for both models as of October 23, 2026. GLM 5.1's coding index rests on 3 independent benchmarks and Qwen3.5-Flash's on 2. Where only one model has a result, the page says so instead of naming a winner.