Claude Opus 4.1 vs GLM 5.3 Flash
GLM 5.3 Flash leads Claude Opus 4.1 on the Artificial Analysis Intelligence Index, 41.8 to 22.8, and GLM 5.3 Flash costs 150.0x less per output token ($0.50 vs $75.00 per million). Updated October 22, 2026; 52 benchmarks have a result for both.
Claude Opus 4.1 or GLM 5.3 Flash: which to pick
Only GLM 5.3 Flash has a coding score, 57.7 on the Vibe Coding Index; Claude Opus 4.1 has none, so the two cannot be ranked on coding.
Pick Claude Opus 4.1 for work measured by Mystery game puzzles or MMLU Pro, where it leads.
- Shared results
- 52
- Claude Opus 4.1 only
- 21
- GLM 5.3 Flash only
- 50
- Like-for-like categories
- 7 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
No call
Only GLM 5.3 Flash has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
GLM 5.3 Flash
GLM 5.3 Flash leads, 41.8 against 22.8.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only GLM 5.3 Flash has a AA Agentic Index result, 50.9.
Directional only
Reasoning
GPQA Diamond
GLM 5.3 Flash
GLM 5.3 Flash leads, 86.4% against 76.3%.
Same board, both measured
Math
AIME
No call
Only Claude Opus 4.1 has a AIME result, 78.2%.
Directional only
Knowledge
MMLU Pro
Claude Opus 4.1
Claude Opus 4.1 leads, 87.9% against 86.1%.
Same board, both measured
Web design
Design Arena: websites
GLM 5.3 Flash
GLM 5.3 Flash leads, 1272 against 1176.
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
GLM 5.3 Flash
GLM 5.3 Flash takes 1.05M tokens against 200K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GLM 5.3 Flash
Claude Opus 4.1 $0.052, GLM 5.3 Flash $0.0004 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GLM 5.3 Flash has the number, $0.02.
Directional only
At a glance
- Coding index
- Claude Opus 4.1 not benchmarked, GLM 5.3 Flash 57.7 from 6 benchmarks.
- Widest category
- Math, 21.0 points apart on average over 5 shared benchmarks.
- Widest single gap
- FrontierMath, tiers 1 to 3: Claude Opus 4.1 12.6% against GLM 5.3 Flash 55.8%, 43.2 points apart on a 0 to 100 scale.
- Output price
- Claude Opus 4.1 $75.00 against GLM 5.3 Flash $0.50 per million output tokens, 150.0x apart.
- Context window
- Claude Opus 4.1 takes 200K tokens, GLM 5.3 Flash 1.05M.
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 | Claude Opus 4.1 | Bars | GLM 5.3 Flash | Ties |
|---|---|---|---|---|
| Coding | 0 | 5 | ||
| Intelligence | 0 | 2 | ||
| Reasoning | 1 | 6 | ||
| Math | 0 | 5 | ||
| Knowledge | 1 | 6 | ||
| Web design | 0 | 8 | ||
| General | 0 | 18 | ||
| All shared boards | 2 | 50 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index05
| Benchmark | Claude Opus 4.1 | GLM 5.3 Flash | Leader |
|---|---|---|---|
| LiveBench coding | Not measured | 80.6% | Only GLM 5.3 Flash measured |
| LMArena WebDev | 1390 | 1607 | GLM 5.3 Flash |
| AA Coding Index | Not measured | 71.5 | Only GLM 5.3 Flash measured |
| LiveCodeBench (Vals AI) | 66.5% | 80.5% | GLM 5.3 Flash |
| SWE-bench Verified (Vals AI) | Not measured | 92.0% | Only GLM 5.3 Flash measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 37.4% | Only GLM 5.3 Flash measured |
| Vibe Code Bench (Vals AI) | Not measured | 30.8% | Only GLM 5.3 Flash measured |
| Code migration (Vals AI) | Not measured | 20.5% | Only GLM 5.3 Flash measured |
| ProgramBench (Vals AI) | Not measured | 0.0% | Only GLM 5.3 Flash measured |
| IOI (Vals AI) | Not measured | 52.5% | Only GLM 5.3 Flash measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 62.9% | Only GLM 5.3 Flash measured |
| Vibe Code Bench 1-100 (Vals AI) | Not measured | 16.0% | Only GLM 5.3 Flash measured |
| 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 | Not measured | 51.6% | Only GLM 5.3 Flash measured |
| Terminal-Bench | 38.0% | Not measured | Only Claude Opus 4.1 measured |
| FrontierCode | Not measured | 31.8% | Only GLM 5.3 Flash measured |
| FrontierSWE | Not measured | 18.1% | Only GLM 5.3 Flash measured |
| WeirdML | 45.9% | Not measured | Only Claude Opus 4.1 measured |
| Cybench | 42.0% | Not measured | Only Claude Opus 4.1 measured |
| ALE-Bench | Not measured | 303.6 | Only GLM 5.3 Flash measured |
| LMArena Text: coding | 1479 | 1507 | GLM 5.3 Flash |
| LMArena Text: software and IT | 1456 | 1500 | GLM 5.3 Flash |
| LMArena WebDev: React | Not measured | 1624 | Only GLM 5.3 Flash measured |
| LMArena WebDev: HTML | 1399 | 1577 | GLM 5.3 Flash |
| LMArena WebDev: from an image | Not measured | 1578 | Only GLM 5.3 Flash measured |
| SciCode | 4.6% | Not measured | Only Claude Opus 4.1 measured |
| Neither model has a result on the other 12 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Claude Opus 4.1 | GLM 5.3 Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | 22.8 | 41.8 | GLM 5.3 Flash |
| Epoch Capabilities Index | 144.1 | 153.1 | GLM 5.3 Flash |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index15 boards, none shared
| Benchmark | Claude Opus 4.1 | GLM 5.3 Flash | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 50.9 | Only GLM 5.3 Flash 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) | Not measured | 0.8% | Only GLM 5.3 Flash measured |
| Finance Agent (Vals AI) | Not measured | 57.9% | Only GLM 5.3 Flash measured |
| Tax Agent Bench (Vals AI) | Not measured | 31.6% | Only GLM 5.3 Flash measured |
| Legal Research Bench (Vals AI) | Not measured | 45.2% | Only GLM 5.3 Flash measured |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 10.4% | Only GLM 5.3 Flash measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 55.9% | Only GLM 5.3 Flash measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 2.9% | Only GLM 5.3 Flash measured |
| APEX-Agents | Not measured | 52.8% | Only GLM 5.3 Flash measured |
| METR time horizons | 66.8% | Not measured | Only Claude Opus 4.1 measured |
| GDPval | 43.6% | Not measured | Only Claude Opus 4.1 measured |
| DeepResearch Bench | 48.3% | Not measured | Only Claude Opus 4.1 measured |
| Neither model has a result on the other 26 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index16
| Benchmark | Claude Opus 4.1 | GLM 5.3 Flash | Leader |
|---|---|---|---|
| GPQA Diamond | 76.3% | 86.4% | GLM 5.3 Flash |
| LiveBench reasoning | Not measured | 77.6% | Only GLM 5.3 Flash measured |
| MMMU Pro (Vals AI) | 77.5% | 86.0% | GLM 5.3 Flash |
| GPQA Diamond (Artificial Analysis run) | Not measured | 91.2% | Only GLM 5.3 Flash measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 39.9% | Only GLM 5.3 Flash measured |
| GPQA Diamond (Epoch AI run) | 77.3% | 90.2% | GLM 5.3 Flash |
| ARC-AGI | Not measured | 91.0% | Only GLM 5.3 Flash measured |
| ARC-AGI-2 | Not measured | 65.8% | Only GLM 5.3 Flash measured |
| SimpleBench | 60.0% | Not measured | Only Claude Opus 4.1 measured |
| Chess puzzles | Not measured | 21.0% | Only GLM 5.3 Flash measured |
| Mystery game puzzles | 21.0% | 8.0% | Claude Opus 4.1 |
| EBR-bench | 7.9% | Not measured | Only Claude Opus 4.1 measured |
| VPCT | 35.0% | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: hard prompts | 1442 | 1490 | GLM 5.3 Flash |
| LMArena Text: expert | 1438 | 1511 | GLM 5.3 Flash |
| LMArena Text: hard prompts in English | 1451 | 1488 | GLM 5.3 Flash |
| LMArena Vision: diagrams | Not measured | 1317 | Only GLM 5.3 Flash measured |
| LMArena Vision: homework | Not measured | 1318 | Only GLM 5.3 Flash measured |
| Neither model has a result on the other 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index05
| Benchmark | Claude Opus 4.1 | GLM 5.3 Flash | Leader |
|---|---|---|---|
| AIME | 78.2% | Not measured | Only Claude Opus 4.1 measured |
| MATH 500 (Vals AI) | 95.4% | Not measured | Only Claude Opus 4.1 measured |
| MGSM (Vals AI) | 94.4% | Not measured | Only Claude Opus 4.1 measured |
| OTIS Mock AIME | 68.9% | 93.9% | GLM 5.3 Flash |
| FrontierMath, tiers 1 to 3 | 12.6% | 55.8% | GLM 5.3 Flash |
| FrontierMath, tier 4 | 2.4% | 17.1% | GLM 5.3 Flash |
| ProofBench | Not measured | 21.0% | Only GLM 5.3 Flash measured |
| LMArena Text: math | 1431 | 1503 | GLM 5.3 Flash |
| LMArena Text: mathematical work | 1434 | 1497 | GLM 5.3 Flash |
| Neither model has a result on the other 4 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index16
| Benchmark | Claude Opus 4.1 | GLM 5.3 Flash | Leader |
|---|---|---|---|
| MMLU Pro | 87.9% | 86.1% | Claude Opus 4.1 |
| LegalBench (Vals AI) | 83.5% | 83.9% | GLM 5.3 Flash |
| TaxEval (Vals AI) | 73.7% | 75.6% | GLM 5.3 Flash |
| MortgageTax (Vals AI) | 61.1% | Not measured | Only Claude Opus 4.1 measured |
| MedQA (Vals AI) | 93.6% | Not measured | Only Claude Opus 4.1 measured |
| MedCode (Vals AI) | 47.2% | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: science | 1422 | 1484 | GLM 5.3 Flash |
| LMArena Text: medicine and healthcare | 1416 | 1475 | GLM 5.3 Flash |
| LMArena Text: legal and government | 1421 | 1473 | GLM 5.3 Flash |
| LMArena Text: business and finance | 1406 | 1460 | GLM 5.3 Flash |
| FACTS Benchmark Suite | 40.4% | Not measured | Only Claude Opus 4.1 measured |
| Neither model has a result on the other 7 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index08
| Benchmark | Claude Opus 4.1 | GLM 5.3 Flash | Leader |
|---|---|---|---|
| Design Arena: websites | 1176 | 1272 | GLM 5.3 Flash |
| Design Arena: UI components | 1162 | 1316 | GLM 5.3 Flash |
| Design Arena: game dev | 1171 | 1278 | GLM 5.3 Flash |
| Design Arena: data viz | 1166 | 1262 | GLM 5.3 Flash |
| Design Arena: 3D | 1152 | 1316 | GLM 5.3 Flash |
| Design Arena: all code categories | 1170 | 1282 | GLM 5.3 Flash |
| Design Arena: SVG | 1152 | 1285 | GLM 5.3 Flash |
| Design Arena: ASCII art | 1167 | 1267 | GLM 5.3 Flash |
| LiveBench design | Not measured | 77.2% | Only GLM 5.3 Flash measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index018
| Benchmark | Claude Opus 4.1 | 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 |
| SAGE (Vals AI) | 31.4% | Not measured | Only Claude Opus 4.1 measured |
| MedScribe (Vals AI) | 73.9% | 88.9% | GLM 5.3 Flash |
| Long context reasoning (AA-LCR) | Not measured | 80.0% | Only GLM 5.3 Flash measured |
| DTBench | 80.0% | Not measured | Only Claude Opus 4.1 measured |
| LMCA | 37.1% | Not measured | Only Claude Opus 4.1 measured |
| Creative writing (Lech Mazur) | 84.7% | Not measured | Only Claude Opus 4.1 measured |
| Surface Evolver Bench | Not measured | 52.5% | Only GLM 5.3 Flash measured |
| LMArena Text | 1419 | 1471 | GLM 5.3 Flash |
| LMArena Text: instruction following | 1435 | 1478 | GLM 5.3 Flash |
| LMArena Text: creative writing | 1412 | 1441 | GLM 5.3 Flash |
| LMArena Vision | Not measured | 1294 | Only GLM 5.3 Flash measured |
| LMArena Text: English | 1433 | 1474 | GLM 5.3 Flash |
| LMArena Text: non-English | 1405 | 1462 | GLM 5.3 Flash |
| LMArena Text: Chinese | 1427 | 1531 | GLM 5.3 Flash |
| LMArena Text: German | 1413 | 1462 | GLM 5.3 Flash |
| LMArena Text: Japanese | 1377 | 1444 | GLM 5.3 Flash |
| LMArena Text: Korean | 1381 | 1436 | GLM 5.3 Flash |
| LMArena Text: French | 1433 | 1491 | GLM 5.3 Flash |
| LMArena Text: Spanish | 1448 | 1475 | GLM 5.3 Flash |
| LMArena Text: Russian | 1422 | 1465 | GLM 5.3 Flash |
| LMArena Text: Polish | 1413 | 1450 | GLM 5.3 Flash |
| LMArena Text: multi-turn | 1444 | 1469 | GLM 5.3 Flash |
| LMArena Text: longer queries | 1455 | 1481 | GLM 5.3 Flash |
| LMArena Text: writing and language | 1418 | 1455 | GLM 5.3 Flash |
| LMArena Text: entertainment and media | 1398 | 1440 | GLM 5.3 Flash |
| LMArena Vision: English | Not measured | 1295 | Only GLM 5.3 Flash measured |
| LMArena Vision: Chinese | Not measured | 1363 | Only GLM 5.3 Flash measured |
| LMArena Vision: reading text | Not measured | 1299 | Only GLM 5.3 Flash measured |
| LMArena Vision: humor | Not measured | 1279 | Only GLM 5.3 Flash measured |
| LMArena Vision: creative writing | Not measured | 1270 | Only GLM 5.3 Flash measured |
| Neither model has a result on the other 14 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Opus 4.1 | 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
GLM 5.3 Flash costs less
Repository review
50K input + 3K output tokens
GLM 5.3 Flash costs less
Agent loop
200K input + 10K output tokens
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 | Anthropic Claude Opus 4.1 | Z.ai GLM 5.3 Flash |
|---|---|---|
| Maker | Anthropic | Z.ai |
| Weights | No public weights listed | Open weights |
| Released | August 5, 2025 | August 26, 2026 |
| Context window | 200K | 1.05M |
| Input $/Mtok | $15.00 | $0.15 |
| Output $/Mtok | $75.00 | $0.50 |
| Coding index | Not benchmarked | 57.7 |
| Independent measurements behind it | 1 | 6 |
| Cost per solved task | Not computable | $0.02 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Opus 4.1 better than GLM 5.3 Flash for coding?
Only GLM 5.3 Flash has a coding score, 57.7 on the Vibe Coding Index; Claude Opus 4.1 has none, so the two cannot be ranked on coding. Pick Claude Opus 4.1 for work measured by Mystery game puzzles or MMLU Pro, where it leads.
Which is cheaper, Claude Opus 4.1 or GLM 5.3 Flash?
Claude Opus 4.1 costs $15.00 per million input tokens and $75.00 per million output tokens; GLM 5.3 Flash costs $0.15 and $0.50. Cost per solved task is known for GLM 5.3 Flash only.
Which has the bigger context window, Claude Opus 4.1 or GLM 5.3 Flash?
GLM 5.3 Flash, with 1.05M tokens against 200K.
How many benchmarks is the Claude Opus 4.1 vs GLM 5.3 Flash comparison based on?
52 benchmarks have a result for both models as of October 22, 2026. Claude Opus 4.1's coding index rests on 1 independent benchmark and GLM 5.3 Flash's on 6. Where only one model has a result, the page says so instead of naming a winner.