GPT-5 Nano vs GPT-6 Astra
Updated October 21, 2026. 60 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
vs boards won of 60 shared
Decision reading
Pick GPT-6 Astra for coding: it scores 88.7 on the Vibe Coding Index against 34.8 for GPT-5 Nano.
Pick GPT-5 Nano when output tokens cost 125.0x less.
Model AGPT-5 NanoOpenAI34.8/1001 independent benchmark$0.109 per solved taskModel BGPT-6 AstraOpenAI88.7/1002 independent benchmarksNo cost per solved task
- Shared results
- 60
- GPT-5 Nano only
- 25
- GPT-6 Astra only
- 59
- Like-for-like categories
- 7 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
GPT-6 Astra
GPT-6 Astra scores 88.7 against 34.8.
1 and 2 benchmarks behind the scores
Intelligence
AA Intelligence Index
GPT-6 Astra
GPT-6 Astra leads, 52.7 against 13.0.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only GPT-6 Astra has a AA Agentic Index result, 51.0.
Directional only
Reasoning
GPQA Diamond
No call
Only GPT-5 Nano has a GPQA Diamond result, 63.4%.
Directional only
Math
AIME
No call
Only GPT-5 Nano has a AIME result, 81.2%.
Directional only
Knowledge
MMLU Pro
No call
Only GPT-5 Nano has a MMLU Pro result, 76.1%.
Directional only
Web design
Design Arena: websites
GPT-6 Astra
GPT-6 Astra leads, 1337 against 1101.
Same board, both measured
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 Nano
GPT-5 Nano $0.0003, GPT-6 Astra $0.035 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GPT-5 Nano has the number, $0.109.
Directional only
At a glance
- Coding index
- GPT-5 Nano 34.8 from 1 benchmark, GPT-6 Astra 88.7 from 2 benchmarks.
- Widest category
- Math, 54.3 points apart on average over 6 shared benchmarks.
- Widest single gap
- FrontierMath, tier 4: GPT-5 Nano 2.4% against GPT-6 Astra 97.6%, 95.2 points apart on a 0 to 100 scale.
- Output price
- GPT-5 Nano $0.40 against GPT-6 Astra $50.00 per million output tokens, 125.0x apart.
- Context window
- GPT-5 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 Nano | Bars | GPT-6 Astra | Ties |
|---|---|---|---|---|
| Coding | 0 | 3 | ||
| Intelligence | 0 | 2 | ||
| Reasoning | 0 | 12 | ||
| Math | 0 | 6 | ||
| Knowledge | 0 | 6 | ||
| Web design | 0 | 6 | ||
| General | 0 | 25 | ||
| All shared boards | 0 | 60 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index03
| Benchmark | GPT-5 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| SWE-bench Verified | 34.8% | Not measured | Only GPT-5 Nano measured |
| LiveBench coding | Not measured | 93.7% | Only GPT-6 Astra measured |
| LMArena WebDev | Not measured | 1774 | Only GPT-6 Astra measured |
| AA Coding Index | Not measured | 76.9 | Only GPT-6 Astra measured |
| LiveCodeBench (Vals AI) | 70.2% | Not measured | Only GPT-5 Nano measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 59.6% | Only GPT-6 Astra measured |
| Vibe Code Bench (Vals AI) | Not measured | 89.6% | Only GPT-6 Astra measured |
| Code migration (Vals AI) | Not measured | 67.7% | Only GPT-6 Astra measured |
| 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) | Not measured | 87.3% | Only GPT-6 Astra measured |
| 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 |
| LiveCodeBench (Artificial Analysis run) | 78.9% | Not measured | Only GPT-5 Nano measured |
| SciCode | Not measured | 56.5% | Only GPT-6 Astra measured |
| Terminal-Bench Hard (Artificial Analysis run) | 17.4% | Not measured | Only GPT-5 Nano measured |
| Terminal-Bench | 21.8% | Not measured | Only GPT-5 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 | 38.1% | 93.3% | GPT-6 Astra |
| MirrorCode | Not measured | 46.7% | Only GPT-6 Astra measured |
| ALE-Bench | Not measured | 2951.3 | Only GPT-6 Astra measured |
| LMArena Text: coding | 1351 | 1489 | GPT-6 Astra |
| LMArena Text: software and IT | 1345 | 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 |
| Neither model has a result on the other 9 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | GPT-5 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| AA Intelligence Index | 13.0 | 52.7 | GPT-6 Astra |
| Epoch Capabilities Index | 139.2 | 168.8 | GPT-6 Astra |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index28 boards, none shared
| Benchmark | GPT-5 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 51.0 | Only GPT-6 Astra measured |
| Design Arena: agents building web apps | Not measured | 1372 | 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 | 1245 | Only GPT-6 Astra measured |
| Design Arena: spreadsheets | Not measured | 1380 | 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) | Not measured | 53.5% | Only GPT-6 Astra measured |
| Tax Agent Bench (Vals AI) | Not measured | 20.7% | Only GPT-6 Astra measured |
| Legal Research Bench (Vals AI) | Not measured | 39.4% | Only GPT-6 Astra measured |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 7.1% | Only GPT-6 Astra measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 71.7% | Only GPT-6 Astra measured |
| 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 | 36.5% | Not measured | Only GPT-5 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 11 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index012
| Benchmark | GPT-5 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| GPQA Diamond | 63.4% | Not measured | Only GPT-5 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) | 70.9% | Not measured | Only GPT-5 Nano measured |
| GPQA Diamond (Artificial Analysis run) | 67.6% | 96.3% | GPT-6 Astra |
| Humanity's Last Exam (Artificial Analysis run) | 9.5% | 54.7% | GPT-6 Astra |
| GPQA Diamond (Epoch AI run) | 69.4% | 95.8% | GPT-6 Astra |
| ARC-AGI | 20.7% | 98.5% | GPT-6 Astra |
| ARC-AGI-2 | 2.6% | 95.0% | GPT-6 Astra |
| Chess puzzles | 22.0% | 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 |
| VPCT | 37.2% | Not measured | Only GPT-5 Nano measured |
| LMArena Text: hard prompts | 1328 | 1463 | GPT-6 Astra |
| LMArena Text: expert | 1321 | 1489 | GPT-6 Astra |
| LMArena Text: hard prompts in English | 1338 | 1464 | GPT-6 Astra |
| LMArena Vision: diagrams | 1141 | 1297 | GPT-6 Astra |
| LMArena Vision: homework | 1157 | 1337 | GPT-6 Astra |
| Neither model has a result on the other 3 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | GPT-5 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| AIME | 81.2% | Not measured | Only GPT-5 Nano measured |
| MATH 500 (Vals AI) | 93.8% | Not measured | Only GPT-5 Nano measured |
| MGSM (Vals AI) | 89.3% | Not measured | Only GPT-5 Nano measured |
| AA Math Index | 83.7 | Not measured | Only GPT-5 Nano measured |
| AIME 2025 (Artificial Analysis run) | 83.7% | Not measured | Only GPT-5 Nano measured |
| OTIS Mock AIME | 81.1% | 100.0% | GPT-6 Astra |
| FrontierMath, tiers 1 to 3 | 20.0% | 93.7% | GPT-6 Astra |
| FrontierMath, tier 4 | 2.4% | 97.6% | GPT-6 Astra |
| ProofBench | 12.0% | 99.0% | GPT-6 Astra |
| MATH level 5 | 95.2% | Not measured | Only GPT-5 Nano measured |
| LMArena Text: math | 1317 | 1465 | GPT-6 Astra |
| LMArena Text: mathematical work | 1326 | 1484 | GPT-6 Astra |
| Neither model has a result on the other 1 board here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | GPT-5 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| MMLU Pro | 76.1% | Not measured | Only GPT-5 Nano measured |
| LegalBench (Vals AI) | 50.1% | Not measured | Only GPT-5 Nano measured |
| CaseLaw (Vals AI) | 52.6% | Not measured | Only GPT-5 Nano measured |
| TaxEval (Vals AI) | 67.4% | Not measured | Only GPT-5 Nano measured |
| MortgageTax (Vals AI) | 53.6% | Not measured | Only GPT-5 Nano measured |
| MedQA (Vals AI) | 93.3% | Not measured | Only GPT-5 Nano measured |
| MedCode (Vals AI) | 30.4% | 48.5% | GPT-6 Astra |
| MMLU Pro (Artificial Analysis run) | 78.0% | Not measured | Only GPT-5 Nano measured |
| SimpleQA Verified | 11.7% | 75.6% | GPT-6 Astra |
| LMArena Text: science | 1318 | 1451 | GPT-6 Astra |
| LMArena Text: medicine and healthcare | 1335 | 1425 | GPT-6 Astra |
| LMArena Text: legal and government | 1298 | 1462 | GPT-6 Astra |
| LMArena Text: business and finance | 1311 | 1439 | GPT-6 Astra |
| Neither model has a result on the other 4 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | GPT-5 Nano | GPT-6 Astra | Leader |
|---|---|---|---|
| Design Arena: websites | 1101 | 1337 | GPT-6 Astra |
| Design Arena: UI components | 1066 | 1394 | GPT-6 Astra |
| Design Arena: game dev | 1045 | 1474 | GPT-6 Astra |
| Design Arena: data viz | 1056 | 1335 | GPT-6 Astra |
| Design Arena: 3D | 966 | 1501 | GPT-6 Astra |
| Design Arena: all code categories | 1084 | 1379 | GPT-6 Astra |
| Design Arena: SVG | Not measured | 1431 | Only GPT-6 Astra measured |
| Design Arena: ASCII art | Not measured | 1359 | 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 index025
| Benchmark | GPT-5 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) | 30.4% | 46.4% | GPT-6 Astra |
| MedScribe (Vals AI) | 72.9% | 87.9% | GPT-6 Astra |
| IFBench | 67.6% | Not measured | Only GPT-5 Nano measured |
| Long context reasoning (AA-LCR) | 45.0% | 80.7% | GPT-6 Astra |
| DTBench | 62.7% | 97.3% | GPT-6 Astra |
| LMCA | 7.9% | 64.4% | GPT-6 Astra |
| Fiction.LiveBench | 44.4% | Not measured | Only GPT-5 Nano measured |
| Furniture assembly | Not measured | 80.0% | Only GPT-6 Astra measured |
| LMArena Text | 1320 | 1441 | GPT-6 Astra |
| LMArena Text: instruction following | 1306 | 1455 | GPT-6 Astra |
| LMArena Text: creative writing | 1249 | 1420 | GPT-6 Astra |
| LMArena Vision | 1159 | 1280 | GPT-6 Astra |
| LMArena Text: English | 1321 | 1447 | GPT-6 Astra |
| LMArena Text: non-English | 1313 | 1432 | GPT-6 Astra |
| LMArena Text: Chinese | 1356 | 1489 | GPT-6 Astra |
| LMArena Text: German | 1327 | 1459 | GPT-6 Astra |
| LMArena Text: Japanese | 1227 | 1405 | GPT-6 Astra |
| LMArena Text: Korean | 1269 | 1428 | GPT-6 Astra |
| LMArena Text: French | Not measured | 1432 | Only GPT-6 Astra measured |
| LMArena Text: Spanish | 1360 | 1422 | GPT-6 Astra |
| LMArena Text: Russian | 1296 | 1438 | GPT-6 Astra |
| LMArena Text: Polish | 1314 | 1422 | GPT-6 Astra |
| LMArena Text: multi-turn | 1311 | 1447 | GPT-6 Astra |
| LMArena Text: longer queries | 1312 | 1460 | GPT-6 Astra |
| LMArena Text: writing and language | 1283 | 1437 | GPT-6 Astra |
| LMArena Text: entertainment and media | 1268 | 1427 | GPT-6 Astra |
| LMArena Vision: English | 1170 | 1280 | GPT-6 Astra |
| LMArena Vision: Chinese | 1176 | 1361 | GPT-6 Astra |
| LMArena Vision: reading text | 1152 | 1292 | GPT-6 Astra |
| LMArena Vision: humor | 1110 | Not measured | Only GPT-5 Nano measured |
| LMArena Vision: creative writing | Not measured | 1286 | Only GPT-6 Astra measured |
| Neither model has a result on the other 13 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5 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 Nano$0.0003Fits in one request
GPT-6 Astra$0.035Fits in one request
GPT-5 Nano costs less
Repository review
50K input + 3K output tokens
GPT-5 Nano$0.0037Fits in one request
GPT-6 Astra$0.650Fits in one request
GPT-5 Nano costs less
Agent loop
200K input + 10K output tokens
GPT-5 Nano$0.014Fits in one request
GPT-6 Astra$2.50Fits in one request
GPT-5 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 Nano | OpenAI GPT-6 Astra |
|---|---|---|
| Maker | OpenAI | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | August 7, 2025 | September 4, 2026 |
| Context window | 400K | 1.05M |
| Input $/Mtok | $0.05 | $10.00 |
| Output $/Mtok | $0.40 | $50.00 |
| Coding index | 34.8 | 88.7 |
| Independent measurements behind it | 1 | 2 |
| Cost per solved task | $0.109 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5 Nano better than GPT-6 Astra for coding?
Pick GPT-6 Astra for coding: it scores 88.7 on the Vibe Coding Index against 34.8 for GPT-5 Nano. Pick GPT-5 Nano when output tokens cost 125.0x less.
Which is cheaper, GPT-5 Nano or GPT-6 Astra?
GPT-5 Nano costs $0.05 per million input tokens and $0.40 per million output tokens; GPT-6 Astra costs $10.00 and $50.00. Cost per solved task is known for GPT-5 Nano only.
Which has the bigger context window, GPT-5 Nano or GPT-6 Astra?
GPT-6 Astra, with 1.05M tokens against 400K.
How many benchmarks is the GPT-5 Nano vs GPT-6 Astra comparison based on?
60 benchmarks have a result for both models as of October 21, 2026. GPT-5 Nano's coding index rests on 1 independent benchmark and GPT-6 Astra's on 2. Where only one model has a result, the page says so instead of naming a winner.