GLM 5 vs GPT-5.1-Codex-Max
Updated October 21, 2026. 4 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
Decision reading
Only GLM 5 has a coding score, 41.7 on the Vibe Coding Index; GPT-5.1-Codex-Max has none, so the two cannot be ranked on coding.
GPT-5.1-Codex-Max has the edge where the context window is larger, 400K against 205K tokens, and where what matters is LiveCodeBench (Vals AI) or Terminal-Bench, where it leads.
- Shared results
- 4
- GLM 5 only
- 71
- GPT-5.1-Codex-Max only
- 2
- Like-for-like categories
- 1 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, six public coding benchmarks
No call
Only GLM 5 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
No call
Only GLM 5 has a AA Intelligence Index result, 27.9.
Directional only
Reasoning
GPQA Diamond
No call
Only GLM 5 has a GPQA Diamond result, 83.3%.
Directional only
Math
AIME
No call
Only GLM 5 has a AIME result, 91.7%.
Directional only
Knowledge
MMLU Pro
No call
Only GLM 5 has a MMLU Pro result, 86.0%.
Directional only
Web design
Design Arena: websites
No call
Only GLM 5 has a Design Arena: websites result, 1247.
Directional only
Long documents
Listed context window
GPT-5.1-Codex-Max
GPT-5.1-Codex-Max takes 400K tokens against 205K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GLM 5
GLM 5 $0.0026, GPT-5.1-Codex-Max $0.0063 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GLM 5 has the number, $0.63.
Directional only
At a glance
- Coding index
- GLM 5 41.7 from 3 benchmarks, GPT-5.1-Codex-Max not benchmarked.
- Widest category
- Coding, 6.6 points apart on average over 4 shared benchmarks.
- Widest single gap
- ALE-Bench: GLM 5 765.6 against GPT-5.1-Codex-Max 1228.3, 15.4 points apart on a 0 to 100 scale.
- Output price
- GLM 5 $3.20 against GPT-5.1-Codex-Max $10.00 per million output tokens, 3.1x apart.
- Context window
- GLM 5 takes 205K tokens, GPT-5.1-Codex-Max 400K.
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 | Bars | GPT-5.1-Codex-Max | Ties |
|---|---|---|---|---|
| Coding | 1 | 3 | ||
| All shared boards | 1 | 3 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index13
| Benchmark | GLM 5 | GPT-5.1-Codex-Max | Leader |
|---|---|---|---|
| SWE-bench Verified | 72.8% | Not measured | Only GLM 5 measured |
| SWE-bench Multilingual | 69.7% | Not measured | Only GLM 5 measured |
| LMArena WebDev | 1435 | Not measured | Only GLM 5 measured |
| LiveCodeBench (Vals AI) | 81.9% | 83.6% | GPT-5.1-Codex-Max |
| SWE-bench Verified (Vals AI) | 71.4% | Not measured | Only GLM 5 measured |
| Vibe Code Bench (Vals AI) | 23.4% | 22.2% | GLM 5 |
| Terminal-Bench Hard (Artificial Analysis run) | 43.2% | Not measured | Only GLM 5 measured |
| Terminal-Bench | 52.4% | 60.4% | GPT-5.1-Codex-Max |
| WeirdML | 48.2% | Not measured | Only GLM 5 measured |
| ALE-Bench | 765.6 | 1228.3 | GPT-5.1-Codex-Max |
| LMArena Text: coding | 1461 | Not measured | Only GLM 5 measured |
| LMArena Text: software and IT | 1460 | Not measured | Only GLM 5 measured |
| LMArena WebDev: React | 1424 | Not measured | Only GLM 5 measured |
| LMArena WebDev: HTML | 1450 | Not measured | Only GLM 5 measured |
| Neither model has a result on the other 24 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | GLM 5 | GPT-5.1-Codex-Max | Leader |
|---|---|---|---|
| AA Intelligence Index | 27.9 | Not measured | Only GLM 5 measured |
| Epoch Capabilities Index | 145.8 | Not measured | Only GLM 5 measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | GLM 5 | GPT-5.1-Codex-Max | Leader |
|---|---|---|---|
| Design Arena: agents building full-stack apps | 1123 | Not measured | Only GLM 5 measured |
| Design Arena: agents building mobile apps | 1136 | Not measured | Only GLM 5 measured |
| Design Arena: agents building Android apps | 1153 | Not measured | Only GLM 5 measured |
| Design Arena: agents building Godot games | 1144 | Not measured | Only GLM 5 measured |
| Design Arena: HTML slides | 1148 | Not measured | Only GLM 5 measured |
| τ²-Bench Telecom | 98.2% | Not measured | Only GLM 5 measured |
| METR time horizons | Not measured | 70.8% | Only GPT-5.1-Codex-Max measured |
| Vending-Bench 2 | $4,432 | Not measured | Only GLM 5 measured |
| Neither model has a result on the other 31 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index10 boards, none shared
| Benchmark | GLM 5 | GPT-5.1-Codex-Max | Leader |
|---|---|---|---|
| GPQA Diamond | 83.3% | Not measured | Only GLM 5 measured |
| GPQA Diamond (Artificial Analysis run) | 82.0% | Not measured | Only GLM 5 measured |
| Humanity's Last Exam (Artificial Analysis run) | 29.3% | Not measured | Only GLM 5 measured |
| GPQA Diamond (Epoch AI run) | 87.8% | Not measured | Only GLM 5 measured |
| ARC-AGI | 44.7% | Not measured | Only GLM 5 measured |
| ARC-AGI-2 | 4.9% | Not measured | Only GLM 5 measured |
| SimpleBench | 53.2% | Not measured | Only GLM 5 measured |
| LMArena Text: hard prompts | 1452 | Not measured | Only GLM 5 measured |
| LMArena Text: expert | 1454 | Not measured | Only GLM 5 measured |
| LMArena Text: hard prompts in English | 1460 | Not measured | Only GLM 5 measured |
| Neither model has a result on the other 11 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index5 boards, none shared
| Benchmark | GLM 5 | GPT-5.1-Codex-Max | Leader |
|---|---|---|---|
| AIME | 91.7% | Not measured | Only GLM 5 measured |
| OTIS Mock AIME | 80.0% | Not measured | Only GLM 5 measured |
| ProofBench | Not measured | 9.0% | Only GPT-5.1-Codex-Max measured |
| LMArena Text: math | 1440 | Not measured | Only GLM 5 measured |
| LMArena Text: mathematical work | 1451 | Not measured | Only GLM 5 measured |
| Neither model has a result on the other 8 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index10 boards, none shared
| Benchmark | GLM 5 | GPT-5.1-Codex-Max | Leader |
|---|---|---|---|
| MMLU Pro | 86.0% | Not measured | Only GLM 5 measured |
| LegalBench (Vals AI) | 84.1% | Not measured | Only GLM 5 measured |
| CaseLaw (Vals AI) | 52.5% | Not measured | Only GLM 5 measured |
| CorpFin (Vals AI) | 62.9% | Not measured | Only GLM 5 measured |
| TaxEval (Vals AI) | 70.0% | Not measured | Only GLM 5 measured |
| MedQA (Vals AI) | 94.3% | Not measured | Only GLM 5 measured |
| LMArena Text: science | 1460 | Not measured | Only GLM 5 measured |
| LMArena Text: medicine and healthcare | 1455 | Not measured | Only GLM 5 measured |
| LMArena Text: legal and government | 1453 | Not measured | Only GLM 5 measured |
| LMArena Text: business and finance | 1430 | Not measured | Only GLM 5 measured |
| Neither model has a result on the other 7 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | GLM 5 | GPT-5.1-Codex-Max | Leader |
|---|---|---|---|
| Design Arena: websites | 1247 | Not measured | Only GLM 5 measured |
| Design Arena: UI components | 1230 | Not measured | Only GLM 5 measured |
| Design Arena: game dev | 1234 | Not measured | Only GLM 5 measured |
| Design Arena: data viz | 1228 | Not measured | Only GLM 5 measured |
| Design Arena: 3D | 1229 | Not measured | Only GLM 5 measured |
| Design Arena: all code categories | 1246 | Not measured | Only GLM 5 measured |
| Design Arena: SVG | 1168 | Not measured | Only GLM 5 measured |
| Design Arena: ASCII art | 1146 | Not measured | Only GLM 5 measured |
| Neither model has a result on the other 1 board here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index20 boards, none shared
| Benchmark | GLM 5 | GPT-5.1-Codex-Max | Leader |
|---|---|---|---|
| IFBench | 72.3% | Not measured | Only GLM 5 measured |
| Long context reasoning (AA-LCR) | 75.7% | Not measured | Only GLM 5 measured |
| CL-bench | 18.7% | Not measured | Only GLM 5 measured |
| LMArena Text | 1446 | Not measured | Only GLM 5 measured |
| LMArena Text: instruction following | 1428 | Not measured | Only GLM 5 measured |
| LMArena Text: creative writing | 1438 | Not measured | Only GLM 5 measured |
| LMArena Text: English | 1458 | Not measured | Only GLM 5 measured |
| LMArena Text: non-English | 1430 | Not measured | Only GLM 5 measured |
| LMArena Text: Chinese | 1511 | Not measured | Only GLM 5 measured |
| LMArena Text: German | 1447 | Not measured | Only GLM 5 measured |
| LMArena Text: Japanese | 1416 | Not measured | Only GLM 5 measured |
| LMArena Text: Korean | 1423 | Not measured | Only GLM 5 measured |
| LMArena Text: French | 1456 | Not measured | Only GLM 5 measured |
| LMArena Text: Spanish | 1454 | Not measured | Only GLM 5 measured |
| LMArena Text: Russian | 1436 | Not measured | Only GLM 5 measured |
| LMArena Text: Polish | 1434 | Not measured | Only GLM 5 measured |
| LMArena Text: multi-turn | 1456 | Not measured | Only GLM 5 measured |
| LMArena Text: longer queries | 1446 | Not measured | Only GLM 5 measured |
| LMArena Text: writing and language | 1437 | Not measured | Only GLM 5 measured |
| LMArena Text: entertainment and media | 1426 | Not measured | Only GLM 5 measured |
| Neither model has a result on the other 26 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GLM 5 | GPT-5.1-Codex-Max | 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 costs less
Repository review
50K input + 3K output tokens
GLM 5 costs less
Agent loop
200K input + 10K output tokens
GLM 5 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 | OpenAI GPT-5.1-Codex-Max |
|---|---|---|
| Maker | Z.ai | OpenAI |
| Weights | Open weights | No public weights listed |
| Released | February 11, 2026 | December 4, 2025 |
| Context window | 205K | 400K |
| Input $/Mtok | $1.00 | $1.25 |
| Output $/Mtok | $3.20 | $10.00 |
| Coding index | 41.7 | Not benchmarked |
| Independent measurements behind it | 3 | 1 |
| Cost per solved task | $0.63 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GLM 5 better than GPT-5.1-Codex-Max for coding?
Only GLM 5 has a coding score, 41.7 on the Vibe Coding Index; GPT-5.1-Codex-Max has none, so the two cannot be ranked on coding. GPT-5.1-Codex-Max has the edge where the context window is larger, 400K against 205K tokens, and where what matters is LiveCodeBench (Vals AI) or Terminal-Bench, where it leads.
Which is cheaper, GLM 5 or GPT-5.1-Codex-Max?
GLM 5 costs $1.00 per million input tokens and $3.20 per million output tokens; GPT-5.1-Codex-Max costs $1.25 and $10.00. Cost per solved task is known for GLM 5 only.
Which has the bigger context window, GLM 5 or GPT-5.1-Codex-Max?
GPT-5.1-Codex-Max, with 400K tokens against 205K.
How many benchmarks is the GLM 5 vs GPT-5.1-Codex-Max comparison based on?
4 benchmarks have a result for both models as of October 21, 2026. GLM 5's coding index rests on 3 independent benchmarks and GPT-5.1-Codex-Max's on 1. Where only one model has a result, the page says so instead of naming a winner.