Claude Sonnet 4.5 vs o1
Claude Sonnet 4.5 leads o1 on the Artificial Analysis Intelligence Index, 20.7 to 15.2, and Claude Sonnet 4.5 costs 4.0x less per output token ($15.00 vs $60.00 per million). Updated October 22, 2026; 52 benchmarks have a result for both.
Claude Sonnet 4.5 or o1: which to pick
Only Claude Sonnet 4.5 has a coding score, 39.5 on the Vibe Coding Index; o1 has none, so the two cannot be ranked on coding.
Pick o1 for work measured by TaxEval (Vals AI) or MedQA (Vals AI), where it leads.
- Shared results
- 52
- Claude Sonnet 4.5 only
- 43
- o1 only
- 17
- 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
No call
Only Claude Sonnet 4.5 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Claude Sonnet 4.5
Claude Sonnet 4.5 leads, 20.7 against 15.2.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Claude Sonnet 4.5 has a AA Agentic Index result, 15.8.
Directional only
Reasoning
GPQA Diamond
Claude Sonnet 4.5
Claude Sonnet 4.5 leads, 81.6% against 73.2%.
Same board, both measured
Math
AIME
Claude Sonnet 4.5
Claude Sonnet 4.5 leads, 88.2% against 71.5%.
Same board, both measured
Knowledge
MMLU Pro
Claude Sonnet 4.5
Claude Sonnet 4.5 leads, 87.4% against 83.5%.
Same board, both measured
Web design
Design Arena: websites
No call
Only Claude Sonnet 4.5 has a Design Arena: websites result, 1189.
Directional only
Long documents
Listed context window
Claude Sonnet 4.5
Claude Sonnet 4.5 takes 1M tokens against 200K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Claude Sonnet 4.5
Claude Sonnet 4.5 $0.011, o1 $0.045 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Claude Sonnet 4.5 has the number, $1.16.
Directional only
At a glance
- Coding index
- Claude Sonnet 4.5 39.5 from 3 benchmarks, o1 not benchmarked.
- Widest category
- Agentic work, 16.3 points apart on average over 1 shared benchmark.
- Widest single gap
- ARC-AGI: Claude Sonnet 4.5 63.7% against o1 30.7%, 33.0 points apart on a 0 to 100 scale.
- Output price
- Claude Sonnet 4.5 $15.00 against o1 $60.00 per million output tokens, 4.0x apart.
- Context window
- Claude Sonnet 4.5 takes 1M tokens, o1 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 | Claude Sonnet 4.5 | Bars | o1 | Ties |
|---|---|---|---|---|
| Coding | 5 | 0 | ||
| Intelligence | 2 | 0 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 9 | 0 | 1 tie | |
| Math | 7 | 0 | ||
| Knowledge | 6 | 3 | ||
| General | 18 | 0 | ||
| All shared boards | 48 | 3 | 1 tie |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index50
| Benchmark | Claude Sonnet 4.5 | o1 | Leader |
|---|---|---|---|
| Aider polyglot | Not measured | 61.7% | Only o1 measured |
| 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 |
| LMArena WebDev | 1394 | Not measured | Only Claude Sonnet 4.5 measured |
| AA Coding Index | 52.1 | 39.7 | Claude Sonnet 4.5 |
| LiveCodeBench (Vals AI) | 73.0% | 50.3% | Claude Sonnet 4.5 |
| SWE-bench Verified (Vals AI) | 70.0% | Not measured | Only Claude Sonnet 4.5 measured |
| Vibe Code Bench (Vals AI) | 22.6% | Not measured | Only Claude Sonnet 4.5 measured |
| LiveCodeBench (Artificial Analysis run) | Not measured | 67.9% | Only o1 measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 12.9% | Only o1 measured |
| Terminal-Bench | 46.5% | Not measured | Only Claude Sonnet 4.5 measured |
| GSO-Bench | 14.7% | Not measured | Only Claude Sonnet 4.5 measured |
| WeirdML | 47.7% | 46.1% | Claude Sonnet 4.5 |
| Cybench | 60.0% | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena Text: coding | 1488 | 1367 | Claude Sonnet 4.5 |
| LMArena Text: software and IT | 1473 | 1366 | Claude Sonnet 4.5 |
| LMArena WebDev: React | 1386 | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena WebDev: HTML | 1399 | Not measured | Only Claude Sonnet 4.5 measured |
| SciCode | Not measured | 4.6% | Only o1 measured |
| Neither model has a result on the other 20 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Sonnet 4.5 | o1 | Leader |
|---|---|---|---|
| AA Intelligence Index | 20.7 | 15.2 | Claude Sonnet 4.5 |
| Epoch Capabilities Index | 146.7 | 141.7 | Claude Sonnet 4.5 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Sonnet 4.5 | o1 | Leader |
|---|---|---|---|
| AA Agentic Index | 15.8 | Not measured | Only Claude Sonnet 4.5 measured |
| Design Arena: agents building web apps | 1060 | Not measured | Only Claude Sonnet 4.5 measured |
| Design Arena: agents building full-stack apps | 1050 | Not measured | Only Claude Sonnet 4.5 measured |
| Design Arena: agents building mobile apps | 1137 | Not measured | Only Claude Sonnet 4.5 measured |
| τ²-Bench Telecom | Not measured | 62.6% | Only o1 measured |
| METR time horizons | 67.4% | 51.1% | Claude Sonnet 4.5 |
| Remote Labor Index | 2.1% | Not measured | Only Claude Sonnet 4.5 measured |
| GDPval | 42.5% | Not measured | Only Claude Sonnet 4.5 measured |
| DeepResearch Bench | 52.6% | Not measured | Only Claude Sonnet 4.5 measured |
| OSWorld | 62.9% | Not measured | Only Claude Sonnet 4.5 measured |
| Vending-Bench 2 | $3,839 | Not measured | Only Claude Sonnet 4.5 measured |
| Berkeley Function Calling Leaderboard (BFCL) | 73.2% | Not measured | Only Claude Sonnet 4.5 measured |
| Neither model has a result on the other 29 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index90
| Benchmark | Claude Sonnet 4.5 | o1 | Leader |
|---|---|---|---|
| GPQA Diamond | 81.6% | 73.2% | Claude Sonnet 4.5 |
| MMMU Pro (Vals AI) | 79.3% | 77.4% | Claude Sonnet 4.5 |
| GPQA Diamond (Artificial Analysis run) | Not measured | 74.7% | Only o1 measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 7.0% | Only o1 measured |
| GPQA Diamond (Epoch AI run) | 82.3% | 76.8% | Claude Sonnet 4.5 |
| ARC-AGI | 63.7% | 30.7% | Claude Sonnet 4.5 |
| ARC-AGI-2 | 13.6% | Not measured | Only Claude Sonnet 4.5 measured |
| SimpleBench | 54.3% | 40.1% | Claude Sonnet 4.5 |
| Chess puzzles | 10.0% | 10.0% | Tie |
| Mystery game puzzles | 17.0% | Not measured | Only Claude Sonnet 4.5 measured |
| EBR-bench | 2.4% | Not measured | Only Claude Sonnet 4.5 measured |
| VPCT | 39.8% | 37.0% | Claude Sonnet 4.5 |
| LMArena Text: hard prompts | 1462 | 1371 | Claude Sonnet 4.5 |
| LMArena Text: expert | 1483 | 1361 | Claude Sonnet 4.5 |
| LMArena Text: hard prompts in English | 1471 | 1372 | Claude Sonnet 4.5 |
| Kagi LLM Benchmark | 57.9% | Not measured | Only Claude Sonnet 4.5 measured |
| Neither model has a result on the other 6 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index70
| Benchmark | Claude Sonnet 4.5 | o1 | Leader |
|---|---|---|---|
| AIME | 88.2% | 71.5% | Claude Sonnet 4.5 |
| MATH 500 (Vals AI) | Not measured | 90.4% | Only o1 measured |
| MGSM (Vals AI) | 94.3% | 89.3% | Claude Sonnet 4.5 |
| OTIS Mock AIME | 77.8% | 73.3% | Claude Sonnet 4.5 |
| FrontierMath, tiers 1 to 3 | 23.9% | 14.7% | Claude Sonnet 4.5 |
| FrontierMath, tier 4 | 2.4% | Not measured | Only Claude Sonnet 4.5 measured |
| ProofBench | 19.0% | Not measured | Only Claude Sonnet 4.5 measured |
| MATH level 5 | 97.7% | 94.7% | Claude Sonnet 4.5 |
| LMArena Text: math | 1449 | 1388 | Claude Sonnet 4.5 |
| LMArena Text: mathematical work | 1462 | 1390 | Claude Sonnet 4.5 |
| Neither model has a result on the other 3 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index63
| Benchmark | Claude Sonnet 4.5 | o1 | Leader |
|---|---|---|---|
| MMLU Pro | 87.4% | 83.5% | Claude Sonnet 4.5 |
| LegalBench (Vals AI) | 84.1% | 80.4% | Claude Sonnet 4.5 |
| CaseLaw (Vals AI) | 62.2% | Not measured | Only Claude Sonnet 4.5 measured |
| CorpFin (Vals AI) | 62.0% | Not measured | Only Claude Sonnet 4.5 measured |
| TaxEval (Vals AI) | 73.3% | 74.3% | o1 |
| MortgageTax (Vals AI) | 64.0% | Not measured | Only Claude Sonnet 4.5 measured |
| MedQA (Vals AI) | 94.7% | 96.5% | o1 |
| MedCode (Vals AI) | 44.1% | Not measured | Only Claude Sonnet 4.5 measured |
| MMLU Pro (Artificial Analysis run) | Not measured | 84.1% | Only o1 measured |
| SimpleQA Verified | 30.7% | 41.1% | o1 |
| GeoBench | Not measured | 80.0% | Only o1 measured |
| LMArena Text: science | 1448 | 1369 | Claude Sonnet 4.5 |
| LMArena Text: medicine and healthcare | 1444 | 1355 | Claude Sonnet 4.5 |
| LMArena Text: legal and government | 1451 | 1368 | Claude Sonnet 4.5 |
| LMArena Text: business and finance | 1440 | 1328 | Claude Sonnet 4.5 |
| FACTS Benchmark Suite | 40.6% | Not measured | Only Claude Sonnet 4.5 measured |
| Neither model has a result on the other 2 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Claude Sonnet 4.5 | o1 | Leader |
|---|---|---|---|
| Design Arena: websites | 1189 | Not measured | Only Claude Sonnet 4.5 measured |
| Design Arena: UI components | 1170 | Not measured | Only Claude Sonnet 4.5 measured |
| Design Arena: game dev | 1166 | Not measured | Only Claude Sonnet 4.5 measured |
| Design Arena: data viz | 1167 | Not measured | Only Claude Sonnet 4.5 measured |
| Design Arena: 3D | 1157 | Not measured | Only Claude Sonnet 4.5 measured |
| Design Arena: all code categories | 1182 | Not measured | Only Claude Sonnet 4.5 measured |
| Design Arena: SVG | 1115 | Not measured | Only Claude Sonnet 4.5 measured |
| Design Arena: ASCII art | 1205 | Not measured | Only Claude Sonnet 4.5 measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index180
| Benchmark | Claude Sonnet 4.5 | o1 | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 36.1% | Not measured | Only Claude Sonnet 4.5 measured |
| MedScribe (Vals AI) | 84.5% | Not measured | Only Claude Sonnet 4.5 measured |
| IFBench | Not measured | 70.3% | Only o1 measured |
| Long context reasoning (AA-LCR) | Not measured | 65.0% | Only o1 measured |
| DTBench | 83.2% | 74.7% | Claude Sonnet 4.5 |
| LMCA | 38.8% | 22.3% | Claude Sonnet 4.5 |
| Fiction.LiveBench | Not measured | 83.3% | Only o1 measured |
| Creative writing (Lech Mazur) | Not measured | 70.2% | Only o1 measured |
| LMArena Text | 1438 | 1366 | Claude Sonnet 4.5 |
| LMArena Text: instruction following | 1459 | 1367 | Claude Sonnet 4.5 |
| LMArena Text: creative writing | 1442 | 1347 | Claude Sonnet 4.5 |
| LMArena Vision | Not measured | 1168 | Only o1 measured |
| LMArena Text: English | 1450 | 1372 | Claude Sonnet 4.5 |
| LMArena Text: non-English | 1425 | 1358 | Claude Sonnet 4.5 |
| LMArena Text: Chinese | 1460 | 1394 | Claude Sonnet 4.5 |
| LMArena Text: German | 1427 | 1337 | Claude Sonnet 4.5 |
| LMArena Text: Japanese | 1390 | 1346 | Claude Sonnet 4.5 |
| LMArena Text: Korean | 1402 | 1396 | Claude Sonnet 4.5 |
| LMArena Text: French | 1459 | 1344 | Claude Sonnet 4.5 |
| LMArena Text: Spanish | 1458 | 1345 | Claude Sonnet 4.5 |
| LMArena Text: Russian | 1437 | 1356 | Claude Sonnet 4.5 |
| LMArena Text: Polish | 1423 | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena Text: multi-turn | 1465 | 1355 | Claude Sonnet 4.5 |
| LMArena Text: longer queries | 1475 | 1378 | Claude Sonnet 4.5 |
| LMArena Text: writing and language | 1442 | 1360 | Claude Sonnet 4.5 |
| LMArena Text: entertainment and media | 1428 | 1358 | Claude Sonnet 4.5 |
| LMArena Vision: English | Not measured | 1162 | Only o1 measured |
| LMArena Vision: Chinese | Not measured | 1235 | Only o1 measured |
| LMArena Document | 1450 | Not measured | Only Claude Sonnet 4.5 measured |
| Neither model has a result on the other 17 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Sonnet 4.5 | o1 | 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 costs less
Repository review
50K input + 3K output tokens
Claude Sonnet 4.5 costs less
Agent loop
200K input + 10K output tokens
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 o1 |
|---|---|---|
| Maker | Anthropic | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | September 29, 2025 | December 17, 2024 |
| Context window | 1M | 200K |
| Input $/Mtok | $3.00 | $15.00 |
| Output $/Mtok | $15.00 | $60.00 |
| Coding index | 39.5 | Not benchmarked |
| Independent measurements behind it | 3 | 0 |
| Cost per solved task | $1.16 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Sonnet 4.5 better than o1 for coding?
Only Claude Sonnet 4.5 has a coding score, 39.5 on the Vibe Coding Index; o1 has none, so the two cannot be ranked on coding. Pick o1 for work measured by TaxEval (Vals AI) or MedQA (Vals AI), where it leads.
Which is cheaper, Claude Sonnet 4.5 or o1?
Claude Sonnet 4.5 costs $3.00 per million input tokens and $15.00 per million output tokens; o1 costs $15.00 and $60.00. Cost per solved task is known for Claude Sonnet 4.5 only.
Which has the bigger context window, Claude Sonnet 4.5 or o1?
Claude Sonnet 4.5, with 1M tokens against 200K.
How many benchmarks is the Claude Sonnet 4.5 vs o1 comparison based on?
52 benchmarks have a result for both models as of October 22, 2026. Claude Sonnet 4.5's coding index rests on 3 independent benchmarks and o1's on 0. Where only one model has a result, the page says so instead of naming a winner.