GPT-5.4 Nano vs GPT-6 Astra
GPT-6 Astra leads GPT-5.4 Nano on coding, 85.1 to 44.8 on the Vibe Coding Index, and GPT-5.4 Nano costs 40.0x less per output token ($1.25 vs $50.00 per million). Updated October 22, 2026; 67 benchmarks have a result for both.
GPT-5.4 Nano or GPT-6 Astra: which to pick
Pick GPT-6 Astra for coding: it scores 85.1 on the Vibe Coding Index against 44.8 for GPT-5.4 Nano.
Pick GPT-5.4 Nano for output tokens 40.0x cheaper ($1.25 vs $50.00 per million).
- Shared results
- 67
- GPT-5.4 Nano only
- 18
- GPT-6 Astra only
- 62
- 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
GPT-6 Astra
GPT-6 Astra scores 85.1 against 44.8.
2 and 5 benchmarks behind the scores
Intelligence
AA Intelligence Index
GPT-6 Astra
GPT-6 Astra leads, 52.7 against 20.7.
Same board, both measured
Agentic work
AA Agentic Index
GPT-6 Astra
GPT-6 Astra leads, 51.0 against 16.0.
Same board, both measured
Reasoning
GPQA Diamond
No call
Only GPT-5.4 Nano has a GPQA Diamond result, 77.5%.
Directional only
Math
AIME
No call
Only GPT-5.4 Nano has a AIME result, 88.8%.
Directional only
Knowledge
MMLU Pro
No call
Only GPT-5.4 Nano has a MMLU Pro result, 77.2%.
Directional only
Web design
Design Arena: websites
No call
Only GPT-6 Astra has a Design Arena: websites result, 1336.
Directional only
General
Vals Index
No call
Only GPT-6 Astra has a Vals Index result, 65.0%.
Directional only
Long documents
Listed context window
GPT-6 Astra
GPT-6 Astra takes 1.05M tokens against 400K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-5.4 Nano
GPT-5.4 Nano $0.0008, GPT-6 Astra $0.035 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GPT-5.4 Nano has the number, $0.14.
Directional only
At a glance
- Coding index
- GPT-5.4 Nano 44.8 from 2 benchmarks, GPT-6 Astra 85.1 from 5 benchmarks.
- Widest category
- Math, 43.8 points apart on average over 6 shared benchmarks.
- Widest single gap
- ProofBench: GPT-5.4 Nano 5.0% against GPT-6 Astra 99.0%, 94.0 points apart on a 0 to 100 scale.
- Output price
- GPT-5.4 Nano $1.25 against GPT-6 Astra $50.00 per million output tokens, 40.0x apart.
- Context window
- GPT-5.4 Nano takes 400K tokens, GPT-6 Astra 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 | GPT-5.4 Nano | Bars | GPT-6 Astra | Ties |
|---|---|---|---|---|
| Coding | 0 | 9 | ||
| Intelligence | 0 | 2 | ||
| Agentic work | 0 | 5 | ||
| Reasoning | 0 | 12 | ||
| Math | 0 | 6 | ||
| Knowledge | 0 | 6 | ||
| General | 0 | 27 | ||
| All shared boards | 0 | 67 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index09
| Benchmark | GPT-5.4 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| LiveBench coding | Not measured | 93.7% | Only GPT-6 Astra measured |
| LMArena WebDev | Not measured | 1774 | Only GPT-6 Astra measured |
| AA Coding Index | 56.1 | 76.9 | GPT-6 Astra |
| LiveCodeBench (Vals AI) | 84.0% | Not measured | Only GPT-5.4 Nano measured |
| SWE-bench Verified (Vals AI) | 69.8% | Not measured | Only GPT-5.4 Nano measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 59.6% | Only GPT-6 Astra measured |
| Vibe Code Bench (Vals AI) | 26.1% | 89.6% | GPT-6 Astra |
| Code migration (Vals AI) | 14.5% | 67.7% | GPT-6 Astra |
| ProgramBench (Vals AI) | Not measured | 5.5% | Only GPT-6 Astra measured |
| IOI (Vals AI) | Not measured | 100.0% | Only GPT-6 Astra measured |
| Terminal-Bench 2.1 (Vals AI) | 41.6% | 87.3% | GPT-6 Astra |
| SWE-bench Multimodal (Vals AI) | Not measured | 43.3% | Only GPT-6 Astra measured |
| Vibe Code Bench 1-100 (Vals AI) | Not measured | 27.6% | Only GPT-6 Astra measured |
| CyberBench (Vals AI) | Not measured | 41.1% | Only GPT-6 Astra measured |
| SciCode | 47.2% | 56.5% | GPT-6 Astra |
| Terminal-Bench Hard (Artificial Analysis run) | 42.4% | Not measured | Only GPT-5.4 Nano measured |
| FrontierCode | Not measured | 53.3% | Only GPT-6 Astra measured |
| FrontierSWE | Not measured | 65.5% | Only GPT-6 Astra measured |
| GSO-Bench | Not measured | 79.4% | Only GPT-6 Astra measured |
| WeirdML | 49.2% | 93.3% | GPT-6 Astra |
| MirrorCode | Not measured | 46.7% | Only GPT-6 Astra measured |
| ALE-Bench | 1004.5 | 2951.3 | GPT-6 Astra |
| LMArena Text: coding | 1404 | 1489 | GPT-6 Astra |
| LMArena Text: software and IT | 1402 | 1474 | GPT-6 Astra |
| LMArena WebDev: React | Not measured | 1798 | Only GPT-6 Astra measured |
| LMArena WebDev: HTML | Not measured | 1775 | Only GPT-6 Astra measured |
| LMArena WebDev: from an image | Not measured | 1726 | Only GPT-6 Astra measured |
| SciCode | Not measured | 12.3% | Only GPT-6 Astra measured |
| SWE-Bench Pro V2 | Not measured | 96.9% | Only GPT-6 Astra measured |
| SWE Atlas: Codebase QnA | Not measured | 59.1% | Only GPT-6 Astra measured |
| SWE Atlas: Refactoring | Not measured | 59.1% | Only GPT-6 Astra measured |
| SWE Atlas: Test Writing | Not measured | 50.7% | Only GPT-6 Astra measured |
| Neither model has a result on the other 11 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | GPT-5.4 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| AA Intelligence Index | 20.7 | 52.7 | GPT-6 Astra |
| Epoch Capabilities Index | 146.0 | 168.8 | GPT-6 Astra |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index05
| Benchmark | GPT-5.4 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| AA Agentic Index | 16.0 | 51.0 | GPT-6 Astra |
| Design Arena: agents building web apps | Not measured | 1374 | Only GPT-6 Astra measured |
| Design Arena: agents building full-stack apps | Not measured | 1357 | Only GPT-6 Astra measured |
| Design Arena: agents building mobile apps | Not measured | 1312 | Only GPT-6 Astra measured |
| Design Arena: agents building Godot games | Not measured | 1348 | Only GPT-6 Astra measured |
| Design Arena: PowerPoint slides | Not measured | 1217 | Only GPT-6 Astra measured |
| Design Arena: spreadsheets | Not measured | 1378 | Only GPT-6 Astra measured |
| LiveBench research | Not measured | 85.2% | Only GPT-6 Astra measured |
| LiveBench browser | Not measured | 84.0% | Only GPT-6 Astra measured |
| LiveBench long agentic | Not measured | 82.4% | Only GPT-6 Astra measured |
| SREBench (Vals AI) | Not measured | 56.9% | Only GPT-6 Astra measured |
| Finance Agent (Vals AI) | 38.2% | 53.5% | GPT-6 Astra |
| Tax Agent Bench (Vals AI) | 5.0% | 20.7% | GPT-6 Astra |
| Legal Research Bench (Vals AI) | 6.3% | 39.4% | GPT-6 Astra |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 7.1% | Only GPT-6 Astra measured |
| Excel Modeling Benchmark (Vals AI) | 44.8% | 71.7% | GPT-6 Astra |
| BioMysteryBench (Vals AI) | Not measured | 79.3% | Only GPT-6 Astra measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 62.9% | Only GPT-6 Astra measured |
| Vals Science Index | Not measured | 65.1% | Only GPT-6 Astra measured |
| Time Horizon Index (Vals AI) | Not measured | 90.5% | Only GPT-6 Astra measured |
| CUA-bench (Vals AI) | Not measured | 19.2% | Only GPT-6 Astra measured |
| Robo-bench (Vals AI) | Not measured | 23.3% | Only GPT-6 Astra measured |
| τ²-Bench Telecom | 76.0% | Not measured | Only GPT-5.4 Nano measured |
| APEX-Agents | Not measured | 64.7% | Only GPT-6 Astra measured |
| Remote Labor Index | Not measured | 20.8% | Only GPT-6 Astra measured |
| BALROG | Not measured | 68.3% | Only GPT-6 Astra measured |
| SpireClimb | Not measured | 25.7% | Only GPT-6 Astra measured |
| Vending-Bench 2 | Not measured | $15,515 | Only GPT-6 Astra measured |
| Neither model has a result on the other 14 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index012
| Benchmark | GPT-5.4 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| GPQA Diamond | 77.5% | Not measured | Only GPT-5.4 Nano measured |
| LiveBench reasoning | Not measured | 92.7% | Only GPT-6 Astra measured |
| MysteryMechanism (Vals AI) | Not measured | 53.1% | Only GPT-6 Astra measured |
| MMMU Pro (Vals AI) | 73.6% | Not measured | Only GPT-5.4 Nano measured |
| GPQA Diamond (Artificial Analysis run) | 81.7% | 96.3% | GPT-6 Astra |
| Humanity's Last Exam (Artificial Analysis run) | 28.3% | 54.7% | GPT-6 Astra |
| GPQA Diamond (Epoch AI run) | 78.5% | 95.8% | GPT-6 Astra |
| ARC-AGI | 51.5% | 98.5% | GPT-6 Astra |
| ARC-AGI-2 | 5.7% | 95.0% | GPT-6 Astra |
| Chess puzzles | 45.0% | 74.0% | GPT-6 Astra |
| Mystery game puzzles | 9.0% | 84.0% | GPT-6 Astra |
| EBR-bench | Not measured | 76.2% | Only GPT-6 Astra measured |
| LMArena Text: hard prompts | 1381 | 1463 | GPT-6 Astra |
| LMArena Text: expert | 1396 | 1489 | GPT-6 Astra |
| LMArena Text: hard prompts in English | 1387 | 1464 | GPT-6 Astra |
| LMArena Vision: diagrams | 1210 | 1297 | GPT-6 Astra |
| LMArena Vision: homework | 1225 | 1337 | GPT-6 Astra |
| Kagi LLM Benchmark | 39.7% | Not measured | Only GPT-5.4 Nano measured |
| Humanity's Last Exam (Scale run) | Not measured | 60.6% | Only GPT-6 Astra measured |
| Neither model has a result on the other 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | GPT-5.4 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| AIME | 88.8% | Not measured | Only GPT-5.4 Nano measured |
| OTIS Mock AIME | 87.8% | 100.0% | GPT-6 Astra |
| FrontierMath, tiers 1 to 3 | 44.9% | 93.7% | GPT-6 Astra |
| FrontierMath, tier 4 | 12.2% | 97.6% | GPT-6 Astra |
| ProofBench | 5.0% | 99.0% | GPT-6 Astra |
| LMArena Text: math | 1405 | 1465 | GPT-6 Astra |
| LMArena Text: mathematical work | 1409 | 1484 | GPT-6 Astra |
| MathArena | Not measured | 81.9% | Only GPT-6 Astra measured |
| Neither model has a result on the other 6 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | GPT-5.4 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| MMLU Pro | 77.2% | Not measured | Only GPT-5.4 Nano measured |
| LegalBench (Vals AI) | 77.9% | Not measured | Only GPT-5.4 Nano measured |
| CaseLaw (Vals AI) | 51.9% | Not measured | Only GPT-5.4 Nano measured |
| CorpFin (Vals AI) | 61.2% | Not measured | Only GPT-5.4 Nano measured |
| TaxEval (Vals AI) | 67.4% | Not measured | Only GPT-5.4 Nano measured |
| MortgageTax (Vals AI) | 59.1% | Not measured | Only GPT-5.4 Nano measured |
| MedCode (Vals AI) | 41.0% | 48.5% | GPT-6 Astra |
| SimpleQA Verified | 11.7% | 75.6% | GPT-6 Astra |
| LMArena Text: science | 1374 | 1451 | GPT-6 Astra |
| LMArena Text: medicine and healthcare | 1369 | 1425 | GPT-6 Astra |
| LMArena Text: legal and government | 1368 | 1462 | GPT-6 Astra |
| LMArena Text: business and finance | 1366 | 1439 | GPT-6 Astra |
| FACTS Benchmark Suite | Not measured | 75.7% | Only GPT-6 Astra measured |
| PRBench Finance | Not measured | 47.5% | Only GPT-6 Astra measured |
| PRBench Legal | Not measured | 48.4% | Only GPT-6 Astra measured |
| 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 | GPT-5.4 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| Design Arena: websites | Not measured | 1336 | Only GPT-6 Astra measured |
| Design Arena: UI components | Not measured | 1394 | Only GPT-6 Astra measured |
| Design Arena: game dev | Not measured | 1480 | Only GPT-6 Astra measured |
| Design Arena: data viz | Not measured | 1334 | Only GPT-6 Astra measured |
| Design Arena: 3D | Not measured | 1500 | Only GPT-6 Astra measured |
| Design Arena: all code categories | Not measured | 1379 | Only GPT-6 Astra measured |
| Design Arena: SVG | Not measured | 1430 | Only GPT-6 Astra measured |
| Design Arena: ASCII art | Not measured | 1353 | Only GPT-6 Astra measured |
| LiveBench design | Not measured | 82.0% | Only GPT-6 Astra measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index027
| Benchmark | GPT-5.4 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| Vals Index | Not measured | 65.0% | Only GPT-6 Astra measured |
| LiveBench data analysis | Not measured | 83.0% | Only GPT-6 Astra measured |
| SAGE (Vals AI) | 38.1% | 46.4% | GPT-6 Astra |
| MedScribe (Vals AI) | 77.1% | 87.9% | GPT-6 Astra |
| Vals Multimodal Index | 47.6% | Not measured | Only GPT-5.4 Nano measured |
| IFBench | 75.9% | Not measured | Only GPT-5.4 Nano measured |
| Long context reasoning (AA-LCR) | 76.7% | 80.7% | GPT-6 Astra |
| DTBench | 80.3% | 97.3% | GPT-6 Astra |
| LMCA | 36.9% | 64.4% | GPT-6 Astra |
| Furniture assembly | Not measured | 80.0% | Only GPT-6 Astra measured |
| LMArena Text | 1372 | 1441 | GPT-6 Astra |
| LMArena Text: instruction following | 1362 | 1455 | GPT-6 Astra |
| LMArena Text: creative writing | 1315 | 1420 | GPT-6 Astra |
| LMArena Vision | 1196 | 1280 | GPT-6 Astra |
| LMArena Text: English | 1381 | 1447 | GPT-6 Astra |
| LMArena Text: non-English | 1359 | 1432 | GPT-6 Astra |
| LMArena Text: Chinese | 1391 | 1489 | GPT-6 Astra |
| LMArena Text: German | 1368 | 1459 | GPT-6 Astra |
| LMArena Text: Japanese | 1343 | 1405 | GPT-6 Astra |
| LMArena Text: Korean | 1321 | 1428 | GPT-6 Astra |
| LMArena Text: French | 1395 | 1432 | GPT-6 Astra |
| LMArena Text: Spanish | 1371 | 1422 | GPT-6 Astra |
| LMArena Text: Russian | 1363 | 1438 | GPT-6 Astra |
| LMArena Text: Polish | 1366 | 1422 | GPT-6 Astra |
| LMArena Text: multi-turn | 1382 | 1447 | GPT-6 Astra |
| LMArena Text: longer queries | 1365 | 1460 | GPT-6 Astra |
| LMArena Text: writing and language | 1338 | 1437 | GPT-6 Astra |
| LMArena Text: entertainment and media | 1325 | 1427 | GPT-6 Astra |
| LMArena Vision: English | 1202 | 1280 | GPT-6 Astra |
| LMArena Vision: Chinese | 1232 | 1361 | GPT-6 Astra |
| LMArena Vision: reading text | 1204 | 1292 | GPT-6 Astra |
| LMArena Vision: humor | 1161 | Not measured | Only GPT-5.4 Nano measured |
| LMArena Vision: recognizing things | 1141 | Not measured | Only GPT-5.4 Nano measured |
| LMArena Vision: creative writing | 1159 | 1286 | GPT-6 Astra |
| 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 | GPT-5.4 Nano | GPT-6 Astra | 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
GPT-5.4 Nano costs less
Repository review
50K input + 3K output tokens
GPT-5.4 Nano costs less
Agent loop
200K input + 10K output tokens
GPT-5.4 Nano 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 | OpenAI GPT-5.4 Nano | OpenAI GPT-6 Astra |
|---|---|---|
| Maker | OpenAI | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | March 17, 2026 | September 4, 2026 |
| Context window | 400K | 1.05M |
| Input $/Mtok | $0.20 | $10.00 |
| Output $/Mtok | $1.25 | $50.00 |
| Coding index | 44.8 | 85.1 |
| Independent measurements behind it | 2 | 5 |
| Cost per solved task | $0.14 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5.4 Nano better than GPT-6 Astra for coding?
Pick GPT-6 Astra for coding: it scores 85.1 on the Vibe Coding Index against 44.8 for GPT-5.4 Nano. Pick GPT-5.4 Nano for output tokens 40.0x cheaper ($1.25 vs $50.00 per million).
Which is cheaper, GPT-5.4 Nano or GPT-6 Astra?
GPT-5.4 Nano costs $0.20 per million input tokens and $1.25 per million output tokens; GPT-6 Astra costs $10.00 and $50.00. Cost per solved task is known for GPT-5.4 Nano only.
Which has the bigger context window, GPT-5.4 Nano or GPT-6 Astra?
GPT-6 Astra, with 1.05M tokens against 400K.
How many benchmarks is the GPT-5.4 Nano vs GPT-6 Astra comparison based on?
67 benchmarks have a result for both models as of October 22, 2026. GPT-5.4 Nano's coding index rests on 2 independent benchmarks and GPT-6 Astra's on 5. Where only one model has a result, the page says so instead of naming a winner.