Claude Sonnet 5.5 vs Gemini 3.1 Pro Preview
Claude Sonnet 5.5 leads Gemini 3.1 Pro Preview on coding, 87.3 to 32.3 on the Vibe Coding Index, and Claude Sonnet 5.5 costs 1.2x less per output token ($10.00 vs $12.00 per million). Updated October 22, 2026; 80 benchmarks have a result for both.
vs boards won of 80 shared
Claude Sonnet 5.5 or Gemini 3.1 Pro Preview: which to pick
Pick Claude Sonnet 5.5 for coding: it scores 87.3 on the Vibe Coding Index against 32.3 for Gemini 3.1 Pro Preview.
Pick Gemini 3.1 Pro Preview for a larger context window (1.05M against 1M tokens) and work measured by SciCode or MedCode (Vals AI), where it leads.
Model AClaude Sonnet 5.5Anthropic87.3/1005 independent benchmarksNo cost per solved taskModel BGemini 3.1 Pro PreviewGoogle32.3/1004 independent benchmarks$0.99 per solved task
- Shared results
- 80
- Claude Sonnet 5.5 only
- 16
- Gemini 3.1 Pro Preview only
- 53
- Like-for-like categories
- 8 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
Claude Sonnet 5.5
Claude Sonnet 5.5 scores 87.3 against 32.3.
5 and 4 benchmarks behind the scores
Intelligence
AA Intelligence Index
Claude Sonnet 5.5
Claude Sonnet 5.5 leads, 56.0 against 29.7.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Gemini 3.1 Pro Preview has a AA Agentic Index result, 8.2.
Directional only
Reasoning
GPQA Diamond
No call
Only Gemini 3.1 Pro Preview has a GPQA Diamond result, 95.5%.
Directional only
Math
AIME
No call
Only Gemini 3.1 Pro Preview has a AIME result, 98.1%.
Directional only
Knowledge
MMLU Pro
No call
Only Gemini 3.1 Pro Preview has a MMLU Pro result, 91.0%.
Directional only
Web design
Design Arena: websites
Claude Sonnet 5.5
Claude Sonnet 5.5 leads, 1326 against 1233.
Same board, both measured
General
Vals Index
No call
Only Claude Sonnet 5.5 has a Vals Index result, 70.8%.
Directional only
Long documents
Listed context window
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Claude Sonnet 5.5
Claude Sonnet 5.5 $0.0070, Gemini 3.1 Pro Preview $0.0080 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Gemini 3.1 Pro Preview has the number, $0.99.
Directional only
At a glance
- Coding index
- Claude Sonnet 5.5 87.3 from 5 benchmarks, Gemini 3.1 Pro Preview 32.3 from 4 benchmarks.
- Widest category
- Agentic work, 31.2 points apart on average over 12 shared benchmarks.
- Widest single gap
- Terminal-Bench 4 (Vals AI): Claude Sonnet 5.5 64.1% against Gemini 3.1 Pro Preview 2.5%, 82.2 points apart on a 0 to 100 scale.
- Output price
- Claude Sonnet 5.5 $10.00 against Gemini 3.1 Pro Preview $12.00 per million output tokens, 1.2x apart.
- Context window
- Claude Sonnet 5.5 takes 1M tokens, Gemini 3.1 Pro Preview 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 5.5 | Bars | Gemini 3.1 Pro Preview | Ties |
|---|---|---|---|---|
| Coding | 14 | 1 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 12 | 0 | ||
| Reasoning | 10 | 0 | ||
| Math | 6 | 0 | ||
| Knowledge | 1 | 5 | ||
| Web design | 6 | 0 | ||
| General | 13 | 11 | ||
| All shared boards | 63 | 17 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index141
| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| LiveBench coding | 94.7% | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena WebDev | 1768 | 1447 | Claude Sonnet 5.5 |
| AA Coding Index | Not measured | 68.8 | Only Gemini 3.1 Pro Preview measured |
| LiveCodeBench (Vals AI) | Not measured | 88.5% | Only Gemini 3.1 Pro Preview measured |
| SWE-bench Verified (Vals AI) | Not measured | 78.8% | Only Gemini 3.1 Pro Preview measured |
| Terminal-Bench 4 (Vals AI) | 64.1% | 2.5% | Claude Sonnet 5.5 |
| Vibe Code Bench (Vals AI) | 92.4% | 32.0% | Claude Sonnet 5.5 |
| Code migration (Vals AI) | 69.8% | 17.3% | Claude Sonnet 5.5 |
| ProgramBench (Vals AI) | 6.5% | 0.0% | Claude Sonnet 5.5 |
| IOI (Vals AI) | 83.1% | 51.8% | Claude Sonnet 5.5 |
| Terminal-Bench 2.1 (Vals AI) | 83.2% | 70.8% | Claude Sonnet 5.5 |
| SWE-bench Multimodal (Vals AI) | 58.3% | Not measured | Only Claude Sonnet 5.5 measured |
| Vibe Code Bench 1-100 (Vals AI) | Not measured | 6.7% | Only Gemini 3.1 Pro Preview measured |
| CyberBench (Vals AI) | 59.6% | Not measured | Only Claude Sonnet 5.5 measured |
| SciCode | 61.0% | 58.7% | Claude Sonnet 5.5 |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 53.8% | Only Gemini 3.1 Pro Preview measured |
| Terminal-Bench | Not measured | 80.2% | Only Gemini 3.1 Pro Preview measured |
| FrontierCode | 52.1% | Not measured | Only Claude Sonnet 5.5 measured |
| FrontierSWE | 61.9% | Not measured | Only Claude Sonnet 5.5 measured |
| GSO-Bench | Not measured | 22.6% | Only Gemini 3.1 Pro Preview measured |
| WeirdML | Not measured | 72.1% | Only Gemini 3.1 Pro Preview measured |
| MirrorCode | Not measured | 8.9% | Only Gemini 3.1 Pro Preview measured |
| ALE-Bench | 1819.1 | 1160.6 | Claude Sonnet 5.5 |
| LMArena Text: coding | 1513 | 1484 | Claude Sonnet 5.5 |
| LMArena Text: software and IT | 1504 | 1487 | Claude Sonnet 5.5 |
| LMArena WebDev: React | 1817 | 1438 | Claude Sonnet 5.5 |
| LMArena WebDev: HTML | 1741 | 1490 | Claude Sonnet 5.5 |
| LMArena WebDev: from an image | 1737 | 1481 | Claude Sonnet 5.5 |
| SciCode | 13.8% | 14.3% | Gemini 3.1 Pro Preview |
| Neither model has a result on the other 10 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| AA Intelligence Index | 56.0 | 29.7 | Claude Sonnet 5.5 |
| Epoch Capabilities Index | 166.2 | Not measured | Only Claude Sonnet 5.5 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index120
| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 8.2 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building web apps | 1305 | 1125 | Claude Sonnet 5.5 |
| Design Arena: agents building full-stack apps | Not measured | 1068 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building mobile apps | 1260 | 1094 | Claude Sonnet 5.5 |
| Design Arena: agents building Android apps | Not measured | 1049 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building Godot games | Not measured | 1236 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building games | Not measured | 1113 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: HTML slides | Not measured | 1103 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: PowerPoint slides | Not measured | 1041 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: spreadsheets | 1260 | Not measured | Only Claude Sonnet 5.5 measured |
| LiveBench research | 83.6% | Not measured | Only Claude Sonnet 5.5 measured |
| LiveBench browser | 84.0% | Not measured | Only Claude Sonnet 5.5 measured |
| LiveBench long agentic | 78.8% | Not measured | Only Claude Sonnet 5.5 measured |
| SREBench (Vals AI) | 30.1% | 0.0% | Claude Sonnet 5.5 |
| Finance Agent (Vals AI) | 58.1% | 43.0% | Claude Sonnet 5.5 |
| Tax Agent Bench (Vals AI) | 42.0% | 9.3% | Claude Sonnet 5.5 |
| Legal Research Bench (Vals AI) | 48.1% | 20.7% | Claude Sonnet 5.5 |
| Harvey's Legal Agent Benchmark (Vals AI) | 10.4% | Not measured | Only Claude Sonnet 5.5 measured |
| Excel Modeling Benchmark (Vals AI) | 75.7% | 52.6% | Claude Sonnet 5.5 |
| BioMysteryBench (Vals AI) | 81.1% | 60.0% | Claude Sonnet 5.5 |
| Terminal-Bench-Science (Vals AI) | 47.1% | 1.4% | Claude Sonnet 5.5 |
| Vals Science Index | 59.1% | 27.4% | Claude Sonnet 5.5 |
| τ²-Bench Telecom | Not measured | 95.6% | Only Gemini 3.1 Pro Preview measured |
| APEX-Agents | 75.5% | 35.1% | Claude Sonnet 5.5 |
| METR time horizons | Not measured | 77.0% | Only Gemini 3.1 Pro Preview measured |
| BALROG | Not measured | 57.0% | Only Gemini 3.1 Pro Preview measured |
| DeepResearch Bench | Not measured | 47.8% | Only Gemini 3.1 Pro Preview measured |
| PostTrainBench | Not measured | 22.0% | Only Gemini 3.1 Pro Preview measured |
| SpireClimb | 1.3% | Not measured | Only Claude Sonnet 5.5 measured |
| Vending-Bench 2 | $11,165 | $911 | Claude Sonnet 5.5 |
| Neither model has a result on the other 11 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index100
| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 95.5% | Only Gemini 3.1 Pro Preview measured |
| LiveBench reasoning | 91.6% | Not measured | Only Claude Sonnet 5.5 measured |
| MysteryMechanism (Vals AI) | 49.1% | 20.7% | Claude Sonnet 5.5 |
| MMMU Pro (Vals AI) | Not measured | 88.2% | Only Gemini 3.1 Pro Preview measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 94.1% | Only Gemini 3.1 Pro Preview measured |
| Humanity's Last Exam (Artificial Analysis run) | 55.0% | 47.0% | Claude Sonnet 5.5 |
| GPQA Diamond (Epoch AI run) | 95.6% | 94.4% | Claude Sonnet 5.5 |
| ARC-AGI | Not measured | 98.0% | Only Gemini 3.1 Pro Preview measured |
| ARC-AGI-2 | Not measured | 77.1% | Only Gemini 3.1 Pro Preview measured |
| SimpleBench | Not measured | 79.6% | Only Gemini 3.1 Pro Preview measured |
| Chess puzzles | 59.0% | 51.0% | Claude Sonnet 5.5 |
| Mystery game puzzles | 65.0% | 34.0% | Claude Sonnet 5.5 |
| EBR-bench | Not measured | 14.3% | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: hard prompts | 1494 | 1485 | Claude Sonnet 5.5 |
| LMArena Text: expert | 1531 | 1483 | Claude Sonnet 5.5 |
| LMArena Text: hard prompts in English | 1502 | 1480 | Claude Sonnet 5.5 |
| LMArena Vision: diagrams | 1329 | 1311 | Claude Sonnet 5.5 |
| LMArena Vision: homework | 1331 | 1316 | Claude Sonnet 5.5 |
| Neither model has a result on the other 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| AIME | Not measured | 98.1% | Only Gemini 3.1 Pro Preview measured |
| OTIS Mock AIME | 100.0% | 95.6% | Claude Sonnet 5.5 |
| FrontierMath, tiers 1 to 3 | 88.8% | 59.6% | Claude Sonnet 5.5 |
| FrontierMath, tier 4 | 80.5% | 26.8% | Claude Sonnet 5.5 |
| ProofBench | 100.0% | 26.0% | Claude Sonnet 5.5 |
| LMArena Text: math | 1497 | 1486 | Claude Sonnet 5.5 |
| LMArena Text: mathematical work | 1510 | 1478 | Claude Sonnet 5.5 |
| Neither model has a result on the other 6 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index15
| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 91.0% | Only Gemini 3.1 Pro Preview measured |
| LegalBench (Vals AI) | Not measured | 87.4% | Only Gemini 3.1 Pro Preview measured |
| CaseLaw (Vals AI) | Not measured | 64.8% | Only Gemini 3.1 Pro Preview measured |
| CorpFin (Vals AI) | Not measured | 64.5% | Only Gemini 3.1 Pro Preview measured |
| TaxEval (Vals AI) | Not measured | 72.9% | Only Gemini 3.1 Pro Preview measured |
| MortgageTax (Vals AI) | Not measured | 69.4% | Only Gemini 3.1 Pro Preview measured |
| MedQA (Vals AI) | Not measured | 96.4% | Only Gemini 3.1 Pro Preview measured |
| MedCode (Vals AI) | 52.9% | 59.1% | Gemini 3.1 Pro Preview |
| SimpleQA Verified | 46.5% | 73.5% | Gemini 3.1 Pro Preview |
| LMArena Text: science | 1483 | 1497 | Gemini 3.1 Pro Preview |
| LMArena Text: medicine and healthcare | 1464 | 1486 | Gemini 3.1 Pro Preview |
| LMArena Text: legal and government | 1483 | 1487 | Gemini 3.1 Pro Preview |
| LMArena Text: business and finance | 1468 | 1459 | Claude Sonnet 5.5 |
| FACTS Benchmark Suite | Not measured | 67.4% | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 4 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| Design Arena: websites | 1326 | 1233 | Claude Sonnet 5.5 |
| Design Arena: UI components | 1368 | 1224 | Claude Sonnet 5.5 |
| Design Arena: game dev | 1471 | 1202 | Claude Sonnet 5.5 |
| Design Arena: data viz | 1392 | 1209 | Claude Sonnet 5.5 |
| Design Arena: 3D | 1445 | 1234 | Claude Sonnet 5.5 |
| Design Arena: all code categories | 1364 | 1231 | Claude Sonnet 5.5 |
| Design Arena: SVG | Not measured | 1285 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: ASCII art | Not measured | 1270 | Only Gemini 3.1 Pro Preview measured |
| LiveBench design | 85.0% | Not measured | Only Claude Sonnet 5.5 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index1311
| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| Vals Index | 70.8% | Not measured | Only Claude Sonnet 5.5 measured |
| LiveBench data analysis | 59.5% | Not measured | Only Claude Sonnet 5.5 measured |
| Public Benefits Bench (Vals AI) | 67.2% | 53.8% | Claude Sonnet 5.5 |
| SAGE (Vals AI) | 51.8% | 48.7% | Claude Sonnet 5.5 |
| MedScribe (Vals AI) | 91.1% | 76.1% | Claude Sonnet 5.5 |
| Vals Multimodal Index | Not measured | 56.1% | Only Gemini 3.1 Pro Preview measured |
| IFBench | Not measured | 77.1% | Only Gemini 3.1 Pro Preview measured |
| Long context reasoning (AA-LCR) | 82.7% | 82.0% | Claude Sonnet 5.5 |
| DTBench | 97.3% | 97.1% | Claude Sonnet 5.5 |
| LMCA | 68.3% | 53.8% | Claude Sonnet 5.5 |
| CL-bench | Not measured | 20.8% | Only Gemini 3.1 Pro Preview measured |
| Furniture assembly | 75.0% | 26.7% | Claude Sonnet 5.5 |
| ExploitBench | Not measured | 26.1% | Only Gemini 3.1 Pro Preview measured |
| CL-bench Life | Not measured | 16.9% | Only Gemini 3.1 Pro Preview measured |
| LMArena Text | 1473 | 1480 | Gemini 3.1 Pro Preview |
| LMArena Text: instruction following | 1492 | 1466 | Claude Sonnet 5.5 |
| LMArena Text: creative writing | 1467 | 1482 | Gemini 3.1 Pro Preview |
| LMArena Vision | 1287 | 1296 | Gemini 3.1 Pro Preview |
| LMArena Text: English | 1484 | 1478 | Claude Sonnet 5.5 |
| LMArena Text: non-English | 1456 | 1476 | Gemini 3.1 Pro Preview |
| LMArena Text: Chinese | 1535 | 1527 | Claude Sonnet 5.5 |
| LMArena Text: German | Not measured | 1490 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: Japanese | Not measured | 1491 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: Korean | Not measured | 1455 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: French | 1499 | 1487 | Claude Sonnet 5.5 |
| LMArena Text: Spanish | 1451 | 1481 | Gemini 3.1 Pro Preview |
| LMArena Text: Russian | 1454 | 1497 | Gemini 3.1 Pro Preview |
| LMArena Text: Polish | Not measured | 1498 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: multi-turn | 1465 | 1487 | Gemini 3.1 Pro Preview |
| LMArena Text: longer queries | 1495 | 1482 | Claude Sonnet 5.5 |
| LMArena Text: writing and language | 1474 | 1481 | Gemini 3.1 Pro Preview |
| LMArena Text: entertainment and media | 1461 | 1465 | Gemini 3.1 Pro Preview |
| LMArena Vision: English | 1289 | 1287 | Claude Sonnet 5.5 |
| LMArena Vision: Chinese | Not measured | 1364 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: reading text | 1297 | 1304 | Gemini 3.1 Pro Preview |
| LMArena Vision: humor | Not measured | 1322 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: captioning | Not measured | 1345 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: recognizing things | Not measured | 1330 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: creative writing | 1242 | 1324 | Gemini 3.1 Pro Preview |
| LMArena Document | Not measured | 1444 | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 6 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview | 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 5.5$0.0070Fits in one request
Gemini 3.1 Pro Preview$0.0080Fits in one request
Claude Sonnet 5.5 costs less
Repository review
50K input + 3K output tokens
Claude Sonnet 5.5$0.130Fits in one request
Gemini 3.1 Pro Preview$0.136Fits in one request
Claude Sonnet 5.5 costs less
Agent loop
200K input + 10K output tokens
Claude Sonnet 5.5$0.500Fits in one request
Gemini 3.1 Pro Preview$0.520Fits in one request
Claude Sonnet 5.5 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 5.5 | Google Gemini 3.1 Pro Preview |
|---|---|---|
| Maker | Anthropic | |
| Weights | No public weights listed | No public weights listed |
| Released | September 28, 2026 | February 19, 2026 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $2.00 | $2.00 |
| Output $/Mtok | $10.00 | $12.00 |
| Coding index | 87.3 | 32.3 |
| Independent measurements behind it | 5 | 4 |
| Cost per solved task | Not computable | $0.99 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Sonnet 5.5 better than Gemini 3.1 Pro Preview for coding?
Pick Claude Sonnet 5.5 for coding: it scores 87.3 on the Vibe Coding Index against 32.3 for Gemini 3.1 Pro Preview. Pick Gemini 3.1 Pro Preview for a larger context window (1.05M against 1M tokens) and work measured by SciCode or MedCode (Vals AI), where it leads.
Which is cheaper, Claude Sonnet 5.5 or Gemini 3.1 Pro Preview?
Claude Sonnet 5.5 costs $2.00 per million input tokens and $10.00 per million output tokens; Gemini 3.1 Pro Preview costs $2.00 and $12.00. Cost per solved task is known for Gemini 3.1 Pro Preview only.
Which has the bigger context window, Claude Sonnet 5.5 or Gemini 3.1 Pro Preview?
Gemini 3.1 Pro Preview, with 1.05M tokens against 1M.
How many benchmarks is the Claude Sonnet 5.5 vs Gemini 3.1 Pro Preview comparison based on?
80 benchmarks have a result for both models as of October 22, 2026. Claude Sonnet 5.5's coding index rests on 5 independent benchmarks and Gemini 3.1 Pro Preview's on 4. Where only one model has a result, the page says so instead of naming a winner.