GLM 5.3 vs o3 Mini
Updated October 21, 2026. 49 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
Decision reading
Pick GLM 5.3 for coding: it scores 73.1 on the Vibe Coding Index against 52.1 for o3 Mini.
o3 Mini is neither cheaper nor larger in context, and leads no benchmark both models were measured on.
- Shared results
- 49
- GLM 5.3 only
- 51
- o3 Mini only
- 21
- Like-for-like categories
- 6 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
GLM 5.3 scores 73.1 against 52.1.
2 benchmarks behind each score
Intelligence
AA Intelligence Index
GLM 5.3
GLM 5.3 leads, 44.8 against 12.5.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only GLM 5.3 has a AA Agentic Index result, 53.1.
Directional only
Reasoning
GPQA Diamond
GLM 5.3
GLM 5.3 leads, 88.1% against 75.5%.
Same board, both measured
Math
AIME
No call
Only o3 Mini has a AIME result, 86.5%.
Directional only
Knowledge
MMLU Pro
GLM 5.3
GLM 5.3 leads, 86.8% against 78.7%.
Same board, both measured
Web design
Design Arena: websites
No call
Only GLM 5.3 has a Design Arena: websites result, 1295.
Directional only
General
Vals Index
No call
Only GLM 5.3 has a Vals Index result, 59.7%.
Directional only
Long documents
Listed context window
GLM 5.3
GLM 5.3 takes 1.05M tokens against 200K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GLM 5.3
GLM 5.3 $0.0008, o3 Mini $0.0033 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GLM 5.3 has the number, $0.36.
Directional only
At a glance
- Coding index
- GLM 5.3 73.1 from 2 benchmarks, o3 Mini 52.1 from 2 benchmarks.
- Widest category
- General, 26.6 points apart on average over 20 shared benchmarks.
- Widest single gap
- FrontierMath, tiers 1 to 3: GLM 5.3 68.8% against o3 Mini 18.6%, 50.2 points apart on a 0 to 100 scale.
- Output price
- GLM 5.3 $1.40 against o3 Mini $4.40 per million output tokens, 3.1x apart.
- Context window
- GLM 5.3 takes 1.05M tokens, o3 Mini 200K.
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 5.3 | Bars | o3 Mini | Ties |
|---|---|---|---|---|
| Coding | 5 | 0 | ||
| Intelligence | 2 | 0 | ||
| Reasoning | 9 | 0 | ||
| Math | 5 | 0 | ||
| Knowledge | 8 | 0 | ||
| General | 20 | 0 | ||
| All shared boards | 49 | 0 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index50
| Benchmark | GLM 5.3 | o3 Mini | Leader |
|---|---|---|---|
| Aider polyglot | Not measured | 60.4% | Only o3 Mini measured |
| SWE-bench Verified | Not measured | 42.4% | Only o3 Mini measured |
| SWE-bench Lite | Not measured | 32.3% | Only o3 Mini measured |
| LiveBench coding | 82.8% | Not measured | Only GLM 5.3 measured |
| LMArena WebDev | 1621 | Not measured | Only GLM 5.3 measured |
| AA Coding Index | 74.8 | Not measured | Only GLM 5.3 measured |
| LiveCodeBench (Vals AI) | 80.5% | 71.5% | GLM 5.3 |
| SWE-bench Verified (Vals AI) | 95.4% | Not measured | Only GLM 5.3 measured |
| Terminal-Bench 4 (Vals AI) | 38.9% | Not measured | Only GLM 5.3 measured |
| Vibe Code Bench (Vals AI) | 78.1% | Not measured | Only GLM 5.3 measured |
| Code migration (Vals AI) | 44.2% | Not measured | Only GLM 5.3 measured |
| ProgramBench (Vals AI) | 1.5% | Not measured | Only GLM 5.3 measured |
| IOI (Vals AI) | 68.4% | Not measured | Only GLM 5.3 measured |
| Terminal-Bench 2.1 (Vals AI) | 71.5% | Not measured | Only GLM 5.3 measured |
| Vibe Code Bench 1-100 (Vals AI) | 20.0% | Not measured | Only GLM 5.3 measured |
| SkillsBench (Vals AI) | 47.5% | Not measured | Only GLM 5.3 measured |
| CyberBench (Vals AI) | 72.1% | Not measured | Only GLM 5.3 measured |
| LiveCodeBench (Artificial Analysis run) | Not measured | 73.4% | Only o3 Mini measured |
| SciCode | 59.0% | 42.8% | GLM 5.3 |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 6.8% | Only o3 Mini measured |
| FrontierCode | 40.1% | Not measured | Only GLM 5.3 measured |
| FrontierSWE | 30.2% | Not measured | Only GLM 5.3 measured |
| GSO-Bench | Not measured | 1.3% | Only o3 Mini measured |
| WeirdML | 75.4% | 43.7% | GLM 5.3 |
| Cybench | Not measured | 22.5% | Only o3 Mini measured |
| ALE-Bench | 1317.4 | Not measured | Only GLM 5.3 measured |
| LMArena Text: coding | 1497 | 1378 | GLM 5.3 |
| LMArena Text: software and IT | 1493 | 1364 | GLM 5.3 |
| LMArena WebDev: React | 1641 | Not measured | Only GLM 5.3 measured |
| LMArena WebDev: HTML | 1595 | Not measured | Only GLM 5.3 measured |
| Neither model has a result on the other 8 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | GLM 5.3 | o3 Mini | Leader |
|---|---|---|---|
| AA Intelligence Index | 44.8 | 12.5 | GLM 5.3 |
| Epoch Capabilities Index | 156.0 | 140.2 | GLM 5.3 |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index17 boards, none shared
| Benchmark | GLM 5.3 | o3 Mini | Leader |
|---|---|---|---|
| AA Agentic Index | 53.1 | Not measured | Only GLM 5.3 measured |
| Design Arena: agents building mobile apps | 1194 | Not measured | Only GLM 5.3 measured |
| Design Arena: HTML slides | 1189 | Not measured | Only GLM 5.3 measured |
| Design Arena: PowerPoint slides | 1255 | Not measured | Only GLM 5.3 measured |
| LiveBench research | 73.2% | Not measured | Only GLM 5.3 measured |
| LiveBench browser | 0.0% | Not measured | Only GLM 5.3 measured |
| LiveBench long agentic | 35.9% | Not measured | Only GLM 5.3 measured |
| SREBench (Vals AI) | 9.2% | Not measured | Only GLM 5.3 measured |
| Finance Agent (Vals AI) | 55.8% | Not measured | Only GLM 5.3 measured |
| Tax Agent Bench (Vals AI) | 39.7% | Not measured | Only GLM 5.3 measured |
| Legal Research Bench (Vals AI) | 49.0% | Not measured | Only GLM 5.3 measured |
| Harvey's Legal Agent Benchmark (Vals AI) | 14.6% | Not measured | Only GLM 5.3 measured |
| Excel Modeling Benchmark (Vals AI) | 56.3% | Not measured | Only GLM 5.3 measured |
| Terminal-Bench-Science (Vals AI) | 5.7% | Not measured | Only GLM 5.3 measured |
| τ²-Bench Telecom | Not measured | 31.3% | Only o3 Mini measured |
| APEX-Agents | 56.6% | Not measured | Only GLM 5.3 measured |
| Vending-Bench 2 | $8,164 | Not measured | Only GLM 5.3 measured |
| Neither model has a result on the other 22 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index90
| Benchmark | GLM 5.3 | o3 Mini | Leader |
|---|---|---|---|
| GPQA Diamond | 88.1% | 75.5% | GLM 5.3 |
| LiveBench reasoning | 85.8% | Not measured | Only GLM 5.3 measured |
| MysteryMechanism (Vals AI) | 23.0% | Not measured | Only GLM 5.3 measured |
| GPQA Diamond (Artificial Analysis run) | 91.7% | 77.3% | GLM 5.3 |
| Humanity's Last Exam (Artificial Analysis run) | 42.3% | 12.0% | GLM 5.3 |
| GPQA Diamond (Epoch AI run) | 90.9% | 77.0% | GLM 5.3 |
| ARC-AGI | Not measured | 34.5% | Only o3 Mini measured |
| ARC-AGI-2 | Not measured | 3.0% | Only o3 Mini measured |
| SimpleBench | Not measured | 22.8% | Only o3 Mini measured |
| Chess puzzles | 37.0% | 15.0% | GLM 5.3 |
| Mystery game puzzles | 33.0% | 7.0% | GLM 5.3 |
| LMArena Text: hard prompts | 1490 | 1365 | GLM 5.3 |
| LMArena Text: expert | 1514 | 1364 | GLM 5.3 |
| LMArena Text: hard prompts in English | 1496 | 1375 | GLM 5.3 |
| Neither model has a result on the other 7 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | GLM 5.3 | o3 Mini | Leader |
|---|---|---|---|
| AIME | Not measured | 86.5% | Only o3 Mini measured |
| MATH 500 (Vals AI) | Not measured | 91.8% | Only o3 Mini measured |
| MGSM (Vals AI) | Not measured | 91.3% | Only o3 Mini measured |
| OTIS Mock AIME | 91.1% | 76.9% | GLM 5.3 |
| FrontierMath, tiers 1 to 3 | 68.8% | 18.6% | GLM 5.3 |
| FrontierMath, tier 4 | 29.3% | 0.0% | GLM 5.3 |
| ProofBench | 49.0% | Not measured | Only GLM 5.3 measured |
| MATH level 5 | Not measured | 96.5% | Only o3 Mini measured |
| LMArena Text: math | 1495 | 1396 | GLM 5.3 |
| LMArena Text: mathematical work | 1497 | 1399 | GLM 5.3 |
| Neither model has a result on the other 3 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index80
| Benchmark | GLM 5.3 | o3 Mini | Leader |
|---|---|---|---|
| MMLU Pro | 86.8% | 78.7% | GLM 5.3 |
| LegalBench (Vals AI) | 84.8% | 71.5% | GLM 5.3 |
| CorpFin (Vals AI) | Not measured | 45.3% | Only o3 Mini measured |
| TaxEval (Vals AI) | 72.4% | 69.4% | GLM 5.3 |
| MedQA (Vals AI) | Not measured | 94.8% | Only o3 Mini measured |
| MedCode (Vals AI) | 42.9% | Not measured | Only GLM 5.3 measured |
| MMLU Pro (Artificial Analysis run) | Not measured | 80.2% | Only o3 Mini measured |
| SimpleQA Verified | 41.0% | 15.3% | GLM 5.3 |
| LMArena Text: science | 1498 | 1339 | GLM 5.3 |
| LMArena Text: medicine and healthcare | 1481 | 1330 | GLM 5.3 |
| LMArena Text: legal and government | 1473 | 1328 | GLM 5.3 |
| LMArena Text: business and finance | 1459 | 1313 | GLM 5.3 |
| Neither model has a result on the other 5 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index9 boards, none shared
| Benchmark | GLM 5.3 | o3 Mini | Leader |
|---|---|---|---|
| Design Arena: websites | 1295 | Not measured | Only GLM 5.3 measured |
| Design Arena: UI components | 1314 | Not measured | Only GLM 5.3 measured |
| Design Arena: game dev | 1311 | Not measured | Only GLM 5.3 measured |
| Design Arena: data viz | 1260 | Not measured | Only GLM 5.3 measured |
| Design Arena: 3D | 1332 | Not measured | Only GLM 5.3 measured |
| Design Arena: all code categories | 1304 | Not measured | Only GLM 5.3 measured |
| Design Arena: SVG | 1292 | Not measured | Only GLM 5.3 measured |
| Design Arena: ASCII art | 1213 | Not measured | Only GLM 5.3 measured |
| LiveBench design | 77.3% | Not measured | Only GLM 5.3 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index200
| Benchmark | GLM 5.3 | o3 Mini | Leader |
|---|---|---|---|
| Vals Index | 59.7% | Not measured | Only GLM 5.3 measured |
| LiveBench data analysis | 70.2% | Not measured | Only GLM 5.3 measured |
| Public Benefits Bench (Vals AI) | 68.5% | Not measured | Only GLM 5.3 measured |
| MedScribe (Vals AI) | 88.8% | Not measured | Only GLM 5.3 measured |
| IFBench | Not measured | 67.1% | Only o3 Mini measured |
| Long context reasoning (AA-LCR) | 79.7% | 43.0% | GLM 5.3 |
| DTBench | 87.7% | 68.8% | GLM 5.3 |
| LMCA | 55.5% | 19.0% | GLM 5.3 |
| Fiction.LiveBench | Not measured | 50.0% | Only o3 Mini measured |
| Creative writing (Lech Mazur) | Not measured | 61.7% | Only o3 Mini measured |
| LMArena Text | 1474 | 1337 | GLM 5.3 |
| LMArena Text: instruction following | 1479 | 1337 | GLM 5.3 |
| LMArena Text: creative writing | 1458 | 1286 | GLM 5.3 |
| LMArena Text: English | 1482 | 1351 | GLM 5.3 |
| LMArena Text: non-English | 1459 | 1319 | GLM 5.3 |
| LMArena Text: Chinese | 1532 | 1379 | GLM 5.3 |
| LMArena Text: German | 1488 | 1303 | GLM 5.3 |
| LMArena Text: Japanese | 1460 | 1286 | GLM 5.3 |
| LMArena Text: Korean | 1460 | 1313 | GLM 5.3 |
| LMArena Text: French | 1503 | 1334 | GLM 5.3 |
| LMArena Text: Spanish | 1462 | 1321 | GLM 5.3 |
| LMArena Text: Russian | 1469 | 1304 | GLM 5.3 |
| LMArena Text: Polish | 1466 | 1294 | GLM 5.3 |
| LMArena Text: multi-turn | 1472 | 1320 | GLM 5.3 |
| LMArena Text: longer queries | 1483 | 1343 | GLM 5.3 |
| LMArena Text: writing and language | 1469 | 1313 | GLM 5.3 |
| LMArena Text: entertainment and media | 1447 | 1283 | GLM 5.3 |
| Neither model has a result on the other 19 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GLM 5.3 | o3 Mini | 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 costs less
Repository review
50K input + 3K output tokens
GLM 5.3 costs less
Agent loop
200K input + 10K output tokens
GLM 5.3 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 5.3 | OpenAI o3 Mini |
|---|---|---|
| Maker | Z.ai | OpenAI |
| Weights | Open weights | No public weights listed |
| Released | August 18, 2026 | January 31, 2025 |
| Context window | 1.05M | 200K |
| Input $/Mtok | $0.079 | $1.10 |
| Output $/Mtok | $1.40 | $4.40 |
| Coding index | 73.1 | 52.1 |
| Independent measurements behind it | 2 | 2 |
| Cost per solved task | $0.36 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GLM 5.3 better than o3 Mini for coding?
Pick GLM 5.3 for coding: it scores 73.1 on the Vibe Coding Index against 52.1 for o3 Mini. o3 Mini is neither cheaper nor larger in context, and leads no benchmark both models were measured on.
Which is cheaper, GLM 5.3 or o3 Mini?
GLM 5.3 costs $0.079 per million input tokens and $1.40 per million output tokens; o3 Mini costs $1.10 and $4.40. Cost per solved task is known for GLM 5.3 only.
Which has the bigger context window, GLM 5.3 or o3 Mini?
GLM 5.3, with 1.05M tokens against 200K.
How many benchmarks is the GLM 5.3 vs o3 Mini comparison based on?
49 benchmarks have a result for both models as of October 21, 2026. GLM 5.3's coding index rests on 2 independent benchmarks and o3 Mini's on 2. Where only one model has a result, the page says so instead of naming a winner.