GLM 4.5 Air vs GPT-4o
GLM 4.5 Air costs 9.1x less per output token than GPT-4o ($1.10 vs $10.00 per million). Updated October 22, 2026; 17 benchmarks have a result for both.
GLM 4.5 Air or GPT-4o: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick GLM 4.5 Air for output tokens 9.1x cheaper ($1.10 vs $10.00 per million) and a larger context window (131K against 128K tokens).
- Shared results
- 17
- GLM 4.5 Air only
- 32
- GPT-4o only
- 11
- 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
Neither has a coding score yet.
One side not measured
Intelligence
AA Intelligence Index
No call
Only GLM 4.5 Air has a AA Intelligence Index result, 11.1.
Directional only
Web design
Design Arena: websites
GLM 4.5 Air
GLM 4.5 Air leads, 1146 against 831.
Same board, both measured
Long documents
Listed context window
GLM 4.5 Air
GLM 4.5 Air takes 131K tokens against 128K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GLM 4.5 Air
GLM 4.5 Air $0.0008, GPT-4o $0.0075 per turn.
List prices
At a glance
- Coding index
- GLM 4.5 Air not benchmarked, GPT-4o not benchmarked.
- Widest category
- Math, 52.6 points apart on average over 3 shared benchmarks.
- Widest single gap
- AA Math Index: GLM 4.5 Air 80.7 against GPT-4o 6.0, 74.7 points apart on a 0 to 100 scale.
- Output price
- GLM 4.5 Air $1.10 against GPT-4o $10.00 per million output tokens, 9.1x apart.
- Context window
- GLM 4.5 Air takes 131K tokens, GPT-4o 128K.
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 4.5 Air | Bars | GPT-4o | Ties |
|---|---|---|---|---|
| Coding | 2 | 0 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 2 | 0 | ||
| Math | 3 | 0 | ||
| Knowledge | 1 | 0 | ||
| Web design | 6 | 0 | ||
| General | 1 | 1 | ||
| All shared boards | 16 | 1 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index20
| Benchmark | GLM 4.5 Air | GPT-4o | Leader |
|---|---|---|---|
| SWE-bench Verified | Not measured | 38.8% | Only GPT-4o measured |
| SWE-bench Lite | Not measured | 38.0% | Only GPT-4o measured |
| SWE-bench (full test set) | Not measured | 18.8% | Only GPT-4o measured |
| SWE-bench Multimodal | Not measured | 30.4% | Only GPT-4o measured |
| LiveCodeBench (Artificial Analysis run) | 68.4% | 30.9% | GLM 4.5 Air |
| Terminal-Bench Hard (Artificial Analysis run) | 20.5% | 8.3% | GLM 4.5 Air |
| GSO-Bench | 2.9% | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: coding | 1397 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: software and IT | 1401 | Not measured | Only GLM 4.5 Air measured |
| SciCode | Not measured | 1.5% | Only GPT-4o measured |
| Neither model has a result on the other 33 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | GLM 4.5 Air | GPT-4o | Leader |
|---|---|---|---|
| AA Intelligence Index | 11.1 | Not measured | Only GLM 4.5 Air measured |
| Neither model has a result on the other 1 board here | |||
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GLM 4.5 Air | GPT-4o | Leader |
|---|---|---|---|
| τ²-Bench Telecom | 46.5% | 25.1% | GLM 4.5 Air |
| GDPval | Not measured | 9.9% | Only GPT-4o measured |
| Neither model has a result on the other 40 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | GLM 4.5 Air | GPT-4o | Leader |
|---|---|---|---|
| GPQA Diamond (Artificial Analysis run) | 73.3% | 54.3% | GLM 4.5 Air |
| Humanity's Last Exam (Artificial Analysis run) | 7.0% | 2.4% | GLM 4.5 Air |
| ARC-AGI | Not measured | 4.5% | Only GPT-4o measured |
| ARC-AGI-2 | Not measured | 0.0% | Only GPT-4o measured |
| LMArena Text: hard prompts | 1379 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: expert | 1370 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: hard prompts in English | 1388 | Not measured | Only GLM 4.5 Air measured |
| Kagi LLM Benchmark | 43.0% | Not measured | Only GLM 4.5 Air measured |
| Neither model has a result on the other 15 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | GLM 4.5 Air | GPT-4o | Leader |
|---|---|---|---|
| AA Math Index | 80.7 | 6.0 | GLM 4.5 Air |
| AIME 2025 (Artificial Analysis run) | 80.7% | 6.0% | GLM 4.5 Air |
| LMArena Text: math | 1396 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: mathematical work | 1396 | Not measured | Only GLM 4.5 Air measured |
| MathArena | 12.0% | 3.6% | GLM 4.5 Air |
| Neither model has a result on the other 9 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GLM 4.5 Air | GPT-4o | Leader |
|---|---|---|---|
| MMLU Pro (Artificial Analysis run) | 81.5% | 74.8% | GLM 4.5 Air |
| MMLU | Not measured | 88.1% | Only GPT-4o measured |
| LMArena Text: science | 1407 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: medicine and healthcare | 1402 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: legal and government | 1382 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: business and finance | 1371 | Not measured | Only GLM 4.5 Air measured |
| Neither model has a result on the other 14 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | GLM 4.5 Air | GPT-4o | Leader |
|---|---|---|---|
| Design Arena: websites | 1146 | 831 | GLM 4.5 Air |
| Design Arena: UI components | 1121 | 883 | GLM 4.5 Air |
| Design Arena: game dev | 1093 | 906 | GLM 4.5 Air |
| Design Arena: data viz | 1186 | 858 | GLM 4.5 Air |
| Design Arena: 3D | 1122 | 868 | GLM 4.5 Air |
| Design Arena: all code categories | 1137 | 860 | GLM 4.5 Air |
| Design Arena: SVG | 1070 | Not measured | Only GLM 4.5 Air measured |
| Neither model has a result on the other 2 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index11
| Benchmark | GLM 4.5 Air | GPT-4o | Leader |
|---|---|---|---|
| IFBench | 37.6% | 34.3% | GLM 4.5 Air |
| Long context reasoning (AA-LCR) | 46.7% | 49.3% | GPT-4o |
| DTBench | Not measured | 64.5% | Only GPT-4o measured |
| LMCA | Not measured | 16.6% | Only GPT-4o measured |
| LMArena Text | 1384 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: instruction following | 1354 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: creative writing | 1343 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: English | 1397 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: non-English | 1366 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: Chinese | 1426 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: German | 1377 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: Japanese | 1348 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: Korean | 1308 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: French | 1400 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: Spanish | 1385 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: Russian | 1373 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: Polish | 1368 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: multi-turn | 1371 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: longer queries | 1366 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: writing and language | 1354 | Not measured | Only GLM 4.5 Air measured |
| LMArena Text: entertainment and media | 1339 | Not measured | Only GLM 4.5 Air measured |
| Neither model has a result on the other 27 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GLM 4.5 Air | GPT-4o | 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 4.5 Air costs less
Repository review
50K input + 3K output tokens
GLM 4.5 Air costs less
Agent loop
200K input + 10K output tokens
GLM 4.5 Air 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 4.5 Air | OpenAI GPT-4o |
|---|---|---|
| Maker | Z.ai | OpenAI |
| Weights | Open weights | No public weights listed |
| Released | July 25, 2025 | May 13, 2024 |
| Context window | 131K | 128K |
| Input $/Mtok | $0.20 | $2.50 |
| Output $/Mtok | $1.10 | $10.00 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 0 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GLM 4.5 Air better than GPT-4o for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick GLM 4.5 Air for output tokens 9.1x cheaper ($1.10 vs $10.00 per million) and a larger context window (131K against 128K tokens).
Which is cheaper, GLM 4.5 Air or GPT-4o?
GLM 4.5 Air costs $0.20 per million input tokens and $1.10 per million output tokens; GPT-4o costs $2.50 and $10.00. Cost per solved task is known for neither of them.
Which has the bigger context window, GLM 4.5 Air or GPT-4o?
GLM 4.5 Air, with 131K tokens against 128K.
How many benchmarks is the GLM 4.5 Air vs GPT-4o comparison based on?
17 benchmarks have a result for both models as of October 22, 2026. GLM 4.5 Air's coding index rests on 0 independent benchmarks and GPT-4o's on 0. Where only one model has a result, the page says so instead of naming a winner.