Claude Sonnet 4.5 vs GPT-5.6 Sol
Updated October 21, 2026. 77 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 77 shared
Decision reading
Pick GPT-5.6 Sol for coding: it scores 76.7 on the Vibe Coding Index against 59.1 for Claude Sonnet 4.5.
Pick Claude Sonnet 4.5 when output tokens cost 1.3x less, or when a solved task costs $1.16 against $1.20.
Model AClaude Sonnet 4.5Anthropic59.1/1002 independent benchmarks$1.16 per solved taskModel BGPT-5.6 SolOpenAI76.7/1002 independent benchmarks$1.20 per solved task
- Shared results
- 77
- Claude Sonnet 4.5 only
- 15
- GPT-5.6 Sol only
- 59
- Like-for-like categories
- 8 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-5.6 Sol
GPT-5.6 Sol scores 76.7 against 59.1.
2 benchmarks behind each score
Intelligence
AA Intelligence Index
GPT-5.6 Sol
GPT-5.6 Sol leads, 47.0 against 20.7.
Same board, both measured
Agentic work
AA Agentic Index
GPT-5.6 Sol
GPT-5.6 Sol leads, 50.2 against 15.8.
Same board, both measured
Reasoning
GPQA Diamond
GPT-5.6 Sol
GPT-5.6 Sol leads, 95.2% against 81.6%.
Same board, both measured
Math
AIME
No call
Only Claude Sonnet 4.5 has a AIME result, 88.2%.
Directional only
Knowledge
MMLU Pro
GPT-5.6 Sol
GPT-5.6 Sol leads, 89.1% against 87.4%.
Same board, both measured
Web design
Design Arena: websites
GPT-5.6 Sol
GPT-5.6 Sol leads, 1321 against 1190.
Same board, both measured
Long documents
Listed context window
GPT-5.6 Sol
GPT-5.6 Sol takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Claude Sonnet 4.5
Claude Sonnet 4.5 $0.011, GPT-5.6 Sol $0.014 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Claude Sonnet 4.5
Claude Sonnet 4.5 $1.16, GPT-5.6 Sol $1.20.
Published attempt cost and pass rate
At a glance
- Coding index
- Claude Sonnet 4.5 59.1 from 2 benchmarks, GPT-5.6 Sol 76.7 from 2 benchmarks.
- Widest category
- Math, 40.3 points apart on average over 6 shared benchmarks.
- Widest single gap
- FrontierMath, tier 4: Claude Sonnet 4.5 2.4% against GPT-5.6 Sol 82.9%, 80.5 points apart on a 0 to 100 scale.
- Output price
- Claude Sonnet 4.5 $15.00 against GPT-5.6 Sol $20.00 per million output tokens, 1.3x apart.
- Context window
- Claude Sonnet 4.5 takes 1M tokens, GPT-5.6 Sol 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 | Claude Sonnet 4.5 | Bars | GPT-5.6 Sol | Ties |
|---|---|---|---|---|
| Coding | 0 | 11 | ||
| Intelligence | 0 | 2 | ||
| Agentic work | 0 | 5 | ||
| Reasoning | 0 | 12 | ||
| Math | 0 | 6 | ||
| Knowledge | 2 | 9 | ||
| Web design | 0 | 8 | ||
| General | 2 | 20 | ||
| All shared boards | 4 | 73 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index011
| Benchmark | Claude Sonnet 4.5 | GPT-5.6 Sol | Leader |
|---|---|---|---|
| SWE-bench Verified | 74.8% | Not measured | Only Claude Sonnet 4.5 measured |
| SWE-bench Multilingual | 67.0% | Not measured | Only Claude Sonnet 4.5 measured |
| LiveBench coding | Not measured | 89.7% | Only GPT-5.6 Sol measured |
| LMArena WebDev | 1394 | 1616 | GPT-5.6 Sol |
| AA Coding Index | 52.1 | 77.4 | GPT-5.6 Sol |
| LiveCodeBench (Vals AI) | 73.0% | 82.6% | GPT-5.6 Sol |
| SWE-bench Verified (Vals AI) | 70.0% | 96.2% | GPT-5.6 Sol |
| Terminal-Bench 4 (Vals AI) | Not measured | 37.9% | Only GPT-5.6 Sol measured |
| Vibe Code Bench (Vals AI) | 22.6% | 80.5% | GPT-5.6 Sol |
| Code migration (Vals AI) | Not measured | 52.9% | Only GPT-5.6 Sol measured |
| ProgramBench (Vals AI) | Not measured | 1.5% | Only GPT-5.6 Sol measured |
| IOI (Vals AI) | Not measured | 91.2% | Only GPT-5.6 Sol measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 85.8% | Only GPT-5.6 Sol measured |
| Vibe Code Bench 1-100 (Vals AI) | Not measured | 20.0% | Only GPT-5.6 Sol measured |
| SkillsBench (Vals AI) | Not measured | 54.1% | Only GPT-5.6 Sol measured |
| CyberBench (Vals AI) | Not measured | 76.3% | Only GPT-5.6 Sol measured |
| SciCode | Not measured | 57.8% | Only GPT-5.6 Sol measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 65.9% | Only GPT-5.6 Sol measured |
| Terminal-Bench | 46.5% | Not measured | Only Claude Sonnet 4.5 measured |
| FrontierCode | Not measured | 47.5% | Only GPT-5.6 Sol measured |
| FrontierSWE | Not measured | 32.2% | Only GPT-5.6 Sol measured |
| GSO-Bench | 14.7% | 76.5% | GPT-5.6 Sol |
| WeirdML | 47.7% | 88.8% | GPT-5.6 Sol |
| MirrorCode | Not measured | 20.0% | Only GPT-5.6 Sol measured |
| Cybench | 60.0% | Not measured | Only Claude Sonnet 4.5 measured |
| ALE-Bench | Not measured | 2176.9 | Only GPT-5.6 Sol measured |
| LMArena Text: coding | 1488 | 1496 | GPT-5.6 Sol |
| LMArena Text: software and IT | 1473 | 1489 | GPT-5.6 Sol |
| LMArena WebDev: React | 1386 | 1620 | GPT-5.6 Sol |
| LMArena WebDev: HTML | 1399 | 1618 | GPT-5.6 Sol |
| LMArena WebDev: from an image | Not measured | 1609 | Only GPT-5.6 Sol measured |
| Neither model has a result on the other 7 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Claude Sonnet 4.5 | GPT-5.6 Sol | Leader |
|---|---|---|---|
| AA Intelligence Index | 20.7 | 47.0 | GPT-5.6 Sol |
| Epoch Capabilities Index | 146.7 | 162.8 | GPT-5.6 Sol |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index05
| Benchmark | Claude Sonnet 4.5 | GPT-5.6 Sol | Leader |
|---|---|---|---|
| AA Agentic Index | 15.8 | 50.2 | GPT-5.6 Sol |
| Design Arena: agents building web apps | 1060 | 1245 | GPT-5.6 Sol |
| Design Arena: agents building full-stack apps | 1050 | 1261 | GPT-5.6 Sol |
| Design Arena: agents building mobile apps | 1137 | 1249 | GPT-5.6 Sol |
| Design Arena: agents building Android apps | Not measured | 1246 | Only GPT-5.6 Sol measured |
| Design Arena: agents building Godot games | Not measured | 1260 | Only GPT-5.6 Sol measured |
| Design Arena: agents building games | Not measured | 1267 | Only GPT-5.6 Sol measured |
| Design Arena: HTML slides | Not measured | 1286 | Only GPT-5.6 Sol measured |
| Design Arena: PowerPoint slides | Not measured | 1240 | Only GPT-5.6 Sol measured |
| LiveBench research | Not measured | 54.5% | Only GPT-5.6 Sol measured |
| LiveBench browser | Not measured | 88.0% | Only GPT-5.6 Sol measured |
| LiveBench long agentic | Not measured | 48.5% | Only GPT-5.6 Sol measured |
| SREBench (Vals AI) | Not measured | 30.5% | Only GPT-5.6 Sol measured |
| Finance Agent (Vals AI) | Not measured | 53.8% | Only GPT-5.6 Sol measured |
| Tax Agent Bench (Vals AI) | Not measured | 31.1% | Only GPT-5.6 Sol measured |
| Legal Research Bench (Vals AI) | Not measured | 48.1% | Only GPT-5.6 Sol measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 72.3% | Only GPT-5.6 Sol measured |
| BioMysteryBench (Vals AI) | Not measured | 71.1% | Only GPT-5.6 Sol measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 20.0% | Only GPT-5.6 Sol measured |
| Vals Science Index | Not measured | 41.5% | Only GPT-5.6 Sol measured |
| Time Horizon Index (Vals AI) | Not measured | 23.8% | Only GPT-5.6 Sol measured |
| CUA-bench (Vals AI) | Not measured | 8.3% | Only GPT-5.6 Sol measured |
| τ²-Bench Telecom | Not measured | 85.1% | Only GPT-5.6 Sol measured |
| METR time horizons | 67.4% | Not measured | Only Claude Sonnet 4.5 measured |
| Remote Labor Index | 2.1% | Not measured | Only Claude Sonnet 4.5 measured |
| GDPval | 42.5% | Not measured | Only Claude Sonnet 4.5 measured |
| OSWorld 2.0 | Not measured | 27.3% | Only GPT-5.6 Sol measured |
| BALROG | Not measured | 60.0% | Only GPT-5.6 Sol measured |
| DeepResearch Bench | 52.6% | Not measured | Only Claude Sonnet 4.5 measured |
| PostTrainBench | Not measured | 36.2% | Only GPT-5.6 Sol measured |
| OSWorld | 62.9% | Not measured | Only Claude Sonnet 4.5 measured |
| Vending-Bench 2 | $3,839 | $9,619 | GPT-5.6 Sol |
| LMArena Search | Not measured | 1261 | Only GPT-5.6 Sol measured |
| Neither model has a result on the other 6 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index012
| Benchmark | Claude Sonnet 4.5 | GPT-5.6 Sol | Leader |
|---|---|---|---|
| GPQA Diamond | 81.6% | 95.2% | GPT-5.6 Sol |
| LiveBench reasoning | Not measured | 91.7% | Only GPT-5.6 Sol measured |
| MysteryMechanism (Vals AI) | Not measured | 33.3% | Only GPT-5.6 Sol measured |
| MMMU Pro (Vals AI) | 79.3% | 88.8% | GPT-5.6 Sol |
| GPQA Diamond (Artificial Analysis run) | Not measured | 94.1% | Only GPT-5.6 Sol measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 49.5% | Only GPT-5.6 Sol measured |
| GPQA Diamond (Epoch AI run) | 82.3% | 93.5% | GPT-5.6 Sol |
| ARC-AGI | 63.7% | 97.5% | GPT-5.6 Sol |
| ARC-AGI-2 | 13.6% | 92.5% | GPT-5.6 Sol |
| SimpleBench | 54.3% | 64.8% | GPT-5.6 Sol |
| Chess puzzles | 10.0% | 59.0% | GPT-5.6 Sol |
| Mystery game puzzles | 17.0% | 58.0% | GPT-5.6 Sol |
| EBR-bench | 2.4% | 44.8% | GPT-5.6 Sol |
| VPCT | 39.8% | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena Text: hard prompts | 1462 | 1483 | GPT-5.6 Sol |
| LMArena Text: expert | 1483 | 1517 | GPT-5.6 Sol |
| LMArena Text: hard prompts in English | 1471 | 1477 | GPT-5.6 Sol |
| LMArena Vision: diagrams | Not measured | 1305 | Only GPT-5.6 Sol measured |
| LMArena Vision: homework | Not measured | 1305 | Only GPT-5.6 Sol measured |
| Neither model has a result on the other 2 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | Claude Sonnet 4.5 | GPT-5.6 Sol | Leader |
|---|---|---|---|
| AIME | 88.2% | Not measured | Only Claude Sonnet 4.5 measured |
| MGSM (Vals AI) | 94.3% | Not measured | Only Claude Sonnet 4.5 measured |
| OTIS Mock AIME | 77.8% | 100.0% | GPT-5.6 Sol |
| FrontierMath, tiers 1 to 3 | 23.9% | 89.1% | GPT-5.6 Sol |
| FrontierMath, tier 4 | 2.4% | 82.9% | GPT-5.6 Sol |
| ProofBench | 19.0% | 83.0% | GPT-5.6 Sol |
| MATH level 5 | 97.7% | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena Text: math | 1449 | 1473 | GPT-5.6 Sol |
| LMArena Text: mathematical work | 1462 | 1496 | GPT-5.6 Sol |
| Neither model has a result on the other 4 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index29
| Benchmark | Claude Sonnet 4.5 | GPT-5.6 Sol | Leader |
|---|---|---|---|
| MMLU Pro | 87.4% | 89.1% | GPT-5.6 Sol |
| LegalBench (Vals AI) | 84.1% | 87.0% | GPT-5.6 Sol |
| CaseLaw (Vals AI) | 62.2% | Not measured | Only Claude Sonnet 4.5 measured |
| CorpFin (Vals AI) | 62.0% | 64.4% | GPT-5.6 Sol |
| TaxEval (Vals AI) | 73.3% | 74.8% | GPT-5.6 Sol |
| MortgageTax (Vals AI) | 64.0% | 67.3% | GPT-5.6 Sol |
| MedQA (Vals AI) | 94.7% | Not measured | Only Claude Sonnet 4.5 measured |
| MedCode (Vals AI) | 44.1% | 44.0% | Claude Sonnet 4.5 |
| SimpleQA Verified | 30.7% | 69.7% | GPT-5.6 Sol |
| LMArena Text: science | 1448 | 1455 | GPT-5.6 Sol |
| LMArena Text: medicine and healthcare | 1444 | 1431 | Claude Sonnet 4.5 |
| LMArena Text: legal and government | 1451 | 1476 | GPT-5.6 Sol |
| LMArena Text: business and finance | 1440 | 1457 | GPT-5.6 Sol |
| Neither model has a result on the other 4 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index08
| Benchmark | Claude Sonnet 4.5 | GPT-5.6 Sol | Leader |
|---|---|---|---|
| Design Arena: websites | 1190 | 1321 | GPT-5.6 Sol |
| Design Arena: UI components | 1173 | 1338 | GPT-5.6 Sol |
| Design Arena: game dev | 1166 | 1368 | GPT-5.6 Sol |
| Design Arena: data viz | 1167 | 1323 | GPT-5.6 Sol |
| Design Arena: 3D | 1158 | 1385 | GPT-5.6 Sol |
| Design Arena: all code categories | 1183 | 1341 | GPT-5.6 Sol |
| Design Arena: SVG | 1114 | 1316 | GPT-5.6 Sol |
| Design Arena: ASCII art | 1204 | 1302 | GPT-5.6 Sol |
| LiveBench design | Not measured | 81.6% | Only GPT-5.6 Sol measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index220
| Benchmark | Claude Sonnet 4.5 | GPT-5.6 Sol | Leader |
|---|---|---|---|
| LiveBench data analysis | Not measured | 79.8% | Only GPT-5.6 Sol measured |
| Public Benefits Bench (Vals AI) | Not measured | 66.5% | Only GPT-5.6 Sol measured |
| SAGE (Vals AI) | 36.1% | 52.6% | GPT-5.6 Sol |
| MedScribe (Vals AI) | 84.5% | 85.2% | GPT-5.6 Sol |
| Vals Multimodal Index | Not measured | 72.6% | Only GPT-5.6 Sol measured |
| IFBench | Not measured | 72.7% | Only GPT-5.6 Sol measured |
| Long context reasoning (AA-LCR) | Not measured | 84.0% | Only GPT-5.6 Sol measured |
| DTBench | 83.2% | 95.7% | GPT-5.6 Sol |
| LMCA | 38.8% | 58.5% | GPT-5.6 Sol |
| Surface Evolver Bench | Not measured | 93.1% | Only GPT-5.6 Sol measured |
| Furniture assembly | Not measured | 56.7% | Only GPT-5.6 Sol measured |
| LMArena Text | 1438 | 1457 | GPT-5.6 Sol |
| LMArena Text: instruction following | 1459 | 1483 | GPT-5.6 Sol |
| LMArena Text: creative writing | 1442 | 1449 | GPT-5.6 Sol |
| LMArena Vision | Not measured | 1281 | Only GPT-5.6 Sol measured |
| LMArena Text: English | 1450 | 1457 | GPT-5.6 Sol |
| LMArena Text: non-English | 1425 | 1451 | GPT-5.6 Sol |
| LMArena Text: Chinese | 1460 | 1525 | GPT-5.6 Sol |
| LMArena Text: German | 1427 | 1476 | GPT-5.6 Sol |
| LMArena Text: Japanese | 1390 | 1472 | GPT-5.6 Sol |
| LMArena Text: Korean | 1402 | 1442 | GPT-5.6 Sol |
| LMArena Text: French | 1459 | 1472 | GPT-5.6 Sol |
| LMArena Text: Spanish | 1458 | 1443 | Claude Sonnet 4.5 |
| LMArena Text: Russian | 1437 | 1471 | GPT-5.6 Sol |
| LMArena Text: Polish | 1423 | 1459 | GPT-5.6 Sol |
| LMArena Text: multi-turn | 1465 | 1461 | Claude Sonnet 4.5 |
| LMArena Text: longer queries | 1475 | 1481 | GPT-5.6 Sol |
| LMArena Text: writing and language | 1442 | 1462 | GPT-5.6 Sol |
| LMArena Text: entertainment and media | 1428 | 1450 | GPT-5.6 Sol |
| LMArena Vision: English | Not measured | 1280 | Only GPT-5.6 Sol measured |
| LMArena Vision: Chinese | Not measured | 1313 | Only GPT-5.6 Sol measured |
| LMArena Vision: reading text | Not measured | 1290 | Only GPT-5.6 Sol measured |
| LMArena Vision: humor | Not measured | 1246 | Only GPT-5.6 Sol measured |
| LMArena Vision: creative writing | Not measured | 1283 | Only GPT-5.6 Sol measured |
| LMArena Document | 1450 | 1483 | GPT-5.6 Sol |
| Neither model has a result on the other 11 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Sonnet 4.5 | GPT-5.6 Sol | 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
Claude Sonnet 4.5$0.011Fits in one request
GPT-5.6 Sol$0.014Fits in one request
Claude Sonnet 4.5 costs less
Repository review
50K input + 3K output tokens
Claude Sonnet 4.5$0.195Fits in one request
GPT-5.6 Sol$0.260Fits in one request
Claude Sonnet 4.5 costs less
Agent loop
200K input + 10K output tokens
Claude Sonnet 4.5$0.750Fits in one request
GPT-5.6 Sol$1.00Fits in one request
Claude Sonnet 4.5 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 | Anthropic Claude Sonnet 4.5 | OpenAI GPT-5.6 Sol |
|---|---|---|
| Maker | Anthropic | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | September 29, 2025 | July 9, 2026 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $3.00 | $4.00 |
| Output $/Mtok | $15.00 | $20.00 |
| Coding index | 59.1 | 76.7 |
| Independent measurements behind it | 2 | 2 |
| Cost per solved task | $1.16 | $1.20 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Sonnet 4.5 better than GPT-5.6 Sol for coding?
Pick GPT-5.6 Sol for coding: it scores 76.7 on the Vibe Coding Index against 59.1 for Claude Sonnet 4.5. Pick Claude Sonnet 4.5 when output tokens cost 1.3x less, or when a solved task costs $1.16 against $1.20.
Which is cheaper, Claude Sonnet 4.5 or GPT-5.6 Sol?
Claude Sonnet 4.5 costs $3.00 per million input tokens and $15.00 per million output tokens; GPT-5.6 Sol costs $4.00 and $20.00. Per solved SWE-bench Verified task, Claude Sonnet 4.5 costs $1.16 and GPT-5.6 Sol $1.20.
Which has the bigger context window, Claude Sonnet 4.5 or GPT-5.6 Sol?
GPT-5.6 Sol, with 1.05M tokens against 1M.
How many benchmarks is the Claude Sonnet 4.5 vs GPT-5.6 Sol comparison based on?
77 benchmarks have a result for both models as of October 21, 2026. Claude Sonnet 4.5's coding index rests on 2 independent benchmarks and GPT-5.6 Sol's on 2. Where only one model has a result, the page says so instead of naming a winner.