GPT-6 Astra vs Kimi K3.1 Pro
GPT-6 Astra leads Kimi K3.1 Pro on coding, 85.1 to 82.2 on the Vibe Coding Index, and Kimi K3.1 Pro costs 5.0x less per output token ($10.00 vs $50.00 per million). Updated October 29, 2026; 35 benchmarks have a result for both.
vs boards won of 35 shared
GPT-6 Astra or Kimi K3.1 Pro: which to pick
Pick GPT-6 Astra for coding: it scores 85.1 on the Vibe Coding Index against 82.2 for Kimi K3.1 Pro.
Pick Kimi K3.1 Pro for output tokens 5.0x cheaper ($10.00 vs $50.00 per million) and work measured by Terminal-Bench 4 (Vals AI) or SciCode, where it leads.
Model AGPT-6 AstraOpenAI85.1/1005 independent benchmarksNo cost per solved taskModel BKimi K3.1 ProMoonshot AI82.2/1004 independent benchmarksNo cost per solved task
- Shared results
- 35
- GPT-6 Astra only
- 94
- Kimi K3.1 Pro only
- 0
- 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 82.2.
5 and 4 benchmarks behind the scores
Intelligence
AA Intelligence Index
GPT-6 Astra
GPT-6 Astra leads, 56.9 against 46.0.
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
Web design
Design Arena: websites
GPT-6 Astra
GPT-6 Astra leads, 1338 against 1325.
Same board, both measured
General
Vals Index
GPT-6 Astra
GPT-6 Astra leads, 65.0% against 62.5%.
Same board, both measured
Long documents
Listed context window
GPT-6 Astra
GPT-6 Astra takes 1.05M tokens against 1.05M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Kimi K3.1 Pro
GPT-6 Astra $0.035, Kimi K3.1 Pro $0.0070 per turn.
List prices
At a glance
- Coding index
- GPT-6 Astra 85.1 from 5 benchmarks, Kimi K3.1 Pro 82.2 from 4 benchmarks.
- Widest category
- Math, 15.1 points apart on average over 2 shared benchmarks.
- Widest single gap
- LiveBench long agentic: GPT-6 Astra 77.5% against Kimi K3.1 Pro 39.1%, 38.4 points apart on a 0 to 100 scale.
- Output price
- GPT-6 Astra $50.00 against Kimi K3.1 Pro $10.00 per million output tokens, 5.0x apart.
- Context window
- GPT-6 Astra takes 1.05M tokens, Kimi K3.1 Pro 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-6 Astra | Bars | Kimi K3.1 Pro | Ties |
|---|---|---|---|---|
| Coding | 7 | 2 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 7 | 2 | ||
| Reasoning | 3 | 0 | ||
| Math | 2 | 0 | ||
| Web design | 7 | 1 | ||
| General | 2 | 1 | ||
| All shared boards | 29 | 6 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index72
| Benchmark | GPT-6 Astra | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| LiveBench coding | 93.7% | 81.8% | GPT-6 Astra |
| LMArena WebDev | 1773 | 1695 | GPT-6 Astra |
| AA Coding Index | 76.9 | Not measured | Only GPT-6 Astra measured |
| Terminal-Bench 4 (Vals AI) | 59.6% | 63.6% | Kimi K3.1 Pro |
| Vibe Code Bench (Vals AI) | 89.6% | 84.9% | GPT-6 Astra |
| Code migration (Vals AI) | 67.7% | Not measured | Only GPT-6 Astra measured |
| ProgramBench (Vals AI) | 5.5% | Not measured | Only GPT-6 Astra measured |
| IOI (Vals AI) | 100.0% | 81.9% | GPT-6 Astra |
| Terminal-Bench 2.1 (Vals AI) | 87.3% | Not measured | Only GPT-6 Astra measured |
| SWE-bench Multimodal (Vals AI) | 43.3% | Not measured | Only GPT-6 Astra measured |
| Vibe Code Bench 1-100 (Vals AI) | 27.6% | Not measured | Only GPT-6 Astra measured |
| CyberBench (Vals AI) | 41.1% | Not measured | Only GPT-6 Astra measured |
| SciCode | 56.5% | 60.8% | Kimi K3.1 Pro |
| FrontierCode | 53.3% | Not measured | Only GPT-6 Astra measured |
| FrontierSWE | 65.5% | Not measured | Only GPT-6 Astra measured |
| GSO-Bench | 79.4% | Not measured | Only GPT-6 Astra measured |
| WeirdML | 93.3% | Not measured | Only GPT-6 Astra measured |
| MirrorCode | 46.7% | Not measured | Only GPT-6 Astra measured |
| ALE-Bench | 2951.3 | 1932.8 | GPT-6 Astra |
| LMArena Text: coding | 1488 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: software and IT | 1475 | Not measured | Only GPT-6 Astra measured |
| LMArena WebDev: React | 1790 | 1701 | GPT-6 Astra |
| LMArena WebDev: HTML | 1785 | 1706 | GPT-6 Astra |
| LMArena WebDev: from an image | 1726 | Not measured | Only GPT-6 Astra measured |
| SciCode | 12.3% | Not measured | Only GPT-6 Astra measured |
| SWE-Bench Pro V2 | 96.9% | Not measured | Only GPT-6 Astra measured |
| SWE Atlas: Codebase QnA | 59.1% | Not measured | Only GPT-6 Astra measured |
| SWE Atlas: Refactoring | 59.1% | Not measured | Only GPT-6 Astra measured |
| SWE Atlas: Test Writing | 50.7% | Not measured | Only GPT-6 Astra measured |
| Neither model has a result on the other 14 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GPT-6 Astra | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| AA Intelligence Index | 56.9 | 46.0 | GPT-6 Astra |
| Epoch Capabilities Index | 168.8 | Not measured | Only GPT-6 Astra measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index72
| Benchmark | GPT-6 Astra | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| AA Agentic Index | 51.0 | Not measured | Only GPT-6 Astra measured |
| Design Arena: agents building web apps | 1373 | Not measured | Only GPT-6 Astra measured |
| Design Arena: agents building full-stack apps | 1357 | Not measured | Only GPT-6 Astra measured |
| Design Arena: agents building mobile apps | 1307 | Not measured | Only GPT-6 Astra measured |
| Design Arena: agents building Godot games | 1348 | Not measured | Only GPT-6 Astra measured |
| Design Arena: HTML slides | 1534 | Not measured | Only GPT-6 Astra measured |
| Design Arena: PowerPoint slides | 1413 | Not measured | Only GPT-6 Astra measured |
| Design Arena: spreadsheets | 1391 | Not measured | Only GPT-6 Astra measured |
| LiveBench research | 85.2% | 77.9% | GPT-6 Astra |
| LiveBench browser | 91.3% | 75.9% | GPT-6 Astra |
| LiveBench long agentic | 77.5% | 39.1% | GPT-6 Astra |
| SREBench (Vals AI) | 56.9% | Not measured | Only GPT-6 Astra measured |
| Finance Agent (Vals AI) | 53.5% | Not measured | Only GPT-6 Astra measured |
| Tax Agent Bench (Vals AI) | 20.7% | 24.9% | Kimi K3.1 Pro |
| Legal Research Bench (Vals AI) | 39.4% | 37.5% | GPT-6 Astra |
| Harvey's Legal Agent Benchmark (Vals AI) | 7.1% | 11.7% | Kimi K3.1 Pro |
| Excel Modeling Benchmark (Vals AI) | 71.7% | Not measured | Only GPT-6 Astra measured |
| BioMysteryBench (Vals AI) | 79.3% | 75.6% | GPT-6 Astra |
| Terminal-Bench-Science (Vals AI) | 62.9% | 31.4% | GPT-6 Astra |
| Vals Science Index | 65.1% | 44.4% | GPT-6 Astra |
| Time Horizon Index (Vals AI) | 90.5% | Not measured | Only GPT-6 Astra measured |
| CUA-bench (Vals AI) | 19.2% | Not measured | Only GPT-6 Astra measured |
| Robo-bench (Vals AI) | 23.3% | Not measured | Only GPT-6 Astra measured |
| APEX-Agents | 64.7% | Not measured | Only GPT-6 Astra measured |
| Remote Labor Index | 20.8% | Not measured | Only GPT-6 Astra measured |
| BALROG | 68.3% | Not measured | Only GPT-6 Astra measured |
| SpireClimb | 25.7% | Not measured | Only GPT-6 Astra measured |
| Vending-Bench 2 | $15,515 | Not measured | 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 index30
| Benchmark | GPT-6 Astra | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| LiveBench reasoning | 92.7% | 91.1% | GPT-6 Astra |
| MysteryMechanism (Vals AI) | 53.1% | 26.1% | GPT-6 Astra |
| GPQA Diamond (Artificial Analysis run) | 96.3% | Not measured | Only GPT-6 Astra measured |
| Humanity's Last Exam (Artificial Analysis run) | 54.7% | 52.5% | GPT-6 Astra |
| GPQA Diamond (Epoch AI run) | 95.8% | Not measured | Only GPT-6 Astra measured |
| ARC-AGI | 98.5% | Not measured | Only GPT-6 Astra measured |
| ARC-AGI-2 | 95.0% | Not measured | Only GPT-6 Astra measured |
| Chess puzzles | 74.0% | Not measured | Only GPT-6 Astra measured |
| Mystery game puzzles | 84.0% | Not measured | Only GPT-6 Astra measured |
| EBR-bench | 76.2% | Not measured | Only GPT-6 Astra measured |
| LMArena Text: hard prompts | 1462 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: expert | 1493 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: hard prompts in English | 1465 | Not measured | Only GPT-6 Astra measured |
| LMArena Vision: diagrams | 1297 | Not measured | Only GPT-6 Astra measured |
| LMArena Vision: homework | 1337 | Not measured | Only GPT-6 Astra measured |
| Humanity's Last Exam (Scale run) | 60.6% | Not measured | Only GPT-6 Astra measured |
| Neither model has a result on the other 7 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | GPT-6 Astra | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| OTIS Mock AIME | 100.0% | Not measured | Only GPT-6 Astra measured |
| FrontierMath, tiers 1 to 3 | 93.7% | Not measured | Only GPT-6 Astra measured |
| FrontierMath, tier 4 | 97.6% | Not measured | Only GPT-6 Astra measured |
| ProofBench | 99.0% | 91.0% | GPT-6 Astra |
| LMArena Text: math | 1468 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: mathematical work | 1487 | Not measured | Only GPT-6 Astra measured |
| MathArena | 81.8% | 59.6% | GPT-6 Astra |
| Neither model has a result on the other 7 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index9 boards, none shared
| Benchmark | GPT-6 Astra | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| MedCode (Vals AI) | 48.5% | Not measured | Only GPT-6 Astra measured |
| SimpleQA Verified | 75.6% | Not measured | Only GPT-6 Astra measured |
| LMArena Text: science | 1450 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: medicine and healthcare | 1419 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: legal and government | 1455 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: business and finance | 1438 | Not measured | Only GPT-6 Astra measured |
| FACTS Benchmark Suite | 75.4% | Not measured | Only GPT-6 Astra measured |
| PRBench Finance | 47.5% | Not measured | Only GPT-6 Astra measured |
| PRBench Legal | 48.4% | Not measured | Only GPT-6 Astra measured |
| Neither model has a result on the other 11 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index71
| Benchmark | GPT-6 Astra | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| Design Arena: websites | 1338 | 1325 | GPT-6 Astra |
| Design Arena: UI components | 1396 | 1400 | Kimi K3.1 Pro |
| Design Arena: game dev | 1471 | 1410 | GPT-6 Astra |
| Design Arena: data viz | 1331 | 1300 | GPT-6 Astra |
| Design Arena: 3D | 1503 | 1451 | GPT-6 Astra |
| Design Arena: all code categories | 1384 | 1354 | GPT-6 Astra |
| Design Arena: SVG | 1426 | 1328 | GPT-6 Astra |
| Design Arena: ASCII art | 1348 | Not measured | Only GPT-6 Astra measured |
| LiveBench design | 82.0% | 77.8% | GPT-6 Astra |
GeneralLike-for-likePublic boards, shown as published, kept out of the index21
| Benchmark | GPT-6 Astra | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| Vals Index | 65.0% | 62.5% | GPT-6 Astra |
| LiveBench data analysis | 83.0% | 79.1% | GPT-6 Astra |
| MedScribe (Vals AI) | 87.9% | Not measured | Only GPT-6 Astra measured |
| Long context reasoning (AA-LCR) | 80.7% | 86.3% | Kimi K3.1 Pro |
| DTBench | 97.3% | Not measured | Only GPT-6 Astra measured |
| LMCA | 64.4% | Not measured | Only GPT-6 Astra measured |
| Furniture assembly | 80.0% | Not measured | Only GPT-6 Astra measured |
| LMArena Text | 1441 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: instruction following | 1454 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: creative writing | 1420 | Not measured | Only GPT-6 Astra measured |
| LMArena Vision | 1280 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: English | 1447 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: non-English | 1432 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: Chinese | 1492 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: German | 1459 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: Japanese | 1407 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: Korean | 1430 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: French | 1435 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: Spanish | 1419 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: Russian | 1441 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: Polish | 1423 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: multi-turn | 1448 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: longer queries | 1461 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: writing and language | 1439 | Not measured | Only GPT-6 Astra measured |
| LMArena Text: entertainment and media | 1427 | Not measured | Only GPT-6 Astra measured |
| LMArena Vision: English | 1280 | Not measured | Only GPT-6 Astra measured |
| LMArena Vision: Chinese | 1361 | Not measured | Only GPT-6 Astra measured |
| LMArena Vision: reading text | 1292 | Not measured | Only GPT-6 Astra measured |
| LMArena Vision: creative writing | 1286 | Not measured | Only GPT-6 Astra measured |
| 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 | GPT-6 Astra | Kimi K3.1 Pro | 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-6 Astra$0.035Fits in one request
Kimi K3.1 Pro$0.0070Fits in one request
Kimi K3.1 Pro costs less
Repository review
50K input + 3K output tokens
GPT-6 Astra$0.650Fits in one request
Kimi K3.1 Pro$0.130Fits in one request
Kimi K3.1 Pro costs less
Agent loop
200K input + 10K output tokens
GPT-6 Astra$2.50Fits in one request
Kimi K3.1 Pro$0.500Fits in one request
Kimi K3.1 Pro 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-6 Astra | MoonshotAI Kimi K3.1 Pro |
|---|---|---|
| Maker | OpenAI | Moonshot AI |
| Weights | No public weights listed | No public weights listed |
| Released | September 4, 2026 | October 23, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $10.00 | $2.00 |
| Output $/Mtok | $50.00 | $10.00 |
| Coding index | 85.1 | 82.2 |
| Independent measurements behind it | 5 | 4 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-6 Astra better than Kimi K3.1 Pro for coding?
Pick GPT-6 Astra for coding: it scores 85.1 on the Vibe Coding Index against 82.2 for Kimi K3.1 Pro. Pick Kimi K3.1 Pro for output tokens 5.0x cheaper ($10.00 vs $50.00 per million) and work measured by Terminal-Bench 4 (Vals AI) or SciCode, where it leads.
Which is cheaper, GPT-6 Astra or Kimi K3.1 Pro?
GPT-6 Astra costs $10.00 per million input tokens and $50.00 per million output tokens; Kimi K3.1 Pro costs $2.00 and $10.00. Cost per solved task is known for neither of them.
Which has the bigger context window, GPT-6 Astra or Kimi K3.1 Pro?
GPT-6 Astra, with 1.05M tokens against 1.05M.
How many benchmarks is the GPT-6 Astra vs Kimi K3.1 Pro comparison based on?
35 benchmarks have a result for both models as of October 29, 2026. GPT-6 Astra's coding index rests on 5 independent benchmarks and Kimi K3.1 Pro's on 4. Where only one model has a result, the page says so instead of naming a winner.