Claude Sonnet 5.5 vs Gemini 2.5 Pro
Claude Sonnet 5.5 leads Gemini 2.5 Pro on coding, 87.3 to 19.1 on the Vibe Coding Index, at about the same output price ($10.00 vs $10.00 per million). Updated October 22, 2026; 55 benchmarks have a result for both.
Claude Sonnet 5.5 or Gemini 2.5 Pro: which to pick
Pick Claude Sonnet 5.5 for coding: it scores 87.3 on the Vibe Coding Index against 19.1 for Gemini 2.5 Pro.
Pick Gemini 2.5 Pro for a larger context window (1.05M against 1M tokens) and work measured by LMArena Text: medicine and healthcare or LMArena Text: Spanish, where it leads.
- Shared results
- 55
- Claude Sonnet 5.5 only
- 41
- Gemini 2.5 Pro only
- 35
- 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 19.1.
5 and 3 benchmarks behind the scores
Intelligence
AA Intelligence Index
Claude Sonnet 5.5
Claude Sonnet 5.5 leads, 56.0 against 16.1.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Gemini 2.5 Pro has a AA Agentic Index result, 1.6.
Directional only
Web design
Design Arena: websites
Claude Sonnet 5.5
Claude Sonnet 5.5 leads, 1326 against 1167.
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 2.5 Pro
Gemini 2.5 Pro takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Gemini 2.5 Pro
Claude Sonnet 5.5 $0.0070, Gemini 2.5 Pro $0.0063 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Gemini 2.5 Pro has the number, $0.64.
Directional only
At a glance
- Coding index
- Claude Sonnet 5.5 87.3 from 5 benchmarks, Gemini 2.5 Pro 19.1 from 3 benchmarks.
- Widest category
- Agentic work, 66.2 points apart on average over 1 shared benchmark.
- Widest single gap
- Vibe Code Bench (Vals AI): Claude Sonnet 5.5 92.4% against Gemini 2.5 Pro 0.4%, 92.0 points apart on a 0 to 100 scale.
- Output price
- Both cost $10.00 per million output tokens.
- Context window
- Claude Sonnet 5.5 takes 1M tokens, Gemini 2.5 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 | Claude Sonnet 5.5 | Bars | Gemini 2.5 Pro | Ties |
|---|---|---|---|---|
| Coding | 7 | 0 | ||
| Intelligence | 2 | 0 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 7 | 0 | ||
| Math | 5 | 0 | ||
| Knowledge | 4 | 1 | ||
| Web design | 6 | 0 | ||
| General | 19 | 3 | ||
| All shared boards | 51 | 4 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index70
| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Pro | Leader |
|---|---|---|---|
| SWE-bench Verified | Not measured | 53.6% | Only Gemini 2.5 Pro measured |
| LiveBench coding | 94.7% | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena WebDev | 1768 | 1226 | Claude Sonnet 5.5 |
| AA Coding Index | Not measured | 33.3 | Only Gemini 2.5 Pro measured |
| SWE-bench Verified (Vals AI) | Not measured | 54.4% | Only Gemini 2.5 Pro measured |
| Terminal-Bench 4 (Vals AI) | 64.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Vibe Code Bench (Vals AI) | 92.4% | 0.4% | Claude Sonnet 5.5 |
| Code migration (Vals AI) | 69.8% | Not measured | Only Claude Sonnet 5.5 measured |
| ProgramBench (Vals AI) | 6.5% | Not measured | Only Claude Sonnet 5.5 measured |
| IOI (Vals AI) | 83.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Terminal-Bench 2.1 (Vals AI) | 83.2% | Not measured | Only Claude Sonnet 5.5 measured |
| SWE-bench Multimodal (Vals AI) | 58.3% | Not measured | Only Claude Sonnet 5.5 measured |
| CyberBench (Vals AI) | 59.6% | Not measured | Only Claude Sonnet 5.5 measured |
| LiveCodeBench (Artificial Analysis run) | Not measured | 80.1% | Only Gemini 2.5 Pro measured |
| SciCode | 61.0% | 46.3% | Claude Sonnet 5.5 |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 26.5% | Only Gemini 2.5 Pro measured |
| Terminal-Bench | Not measured | 32.6% | Only Gemini 2.5 Pro 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 | 3.9% | Only Gemini 2.5 Pro measured |
| WeirdML | Not measured | 54.0% | Only Gemini 2.5 Pro measured |
| ALE-Bench | 1819.1 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: coding | 1513 | 1452 | Claude Sonnet 5.5 |
| LMArena Text: software and IT | 1504 | 1459 | Claude Sonnet 5.5 |
| LMArena WebDev: React | 1817 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena WebDev: HTML | 1741 | 1235 | Claude Sonnet 5.5 |
| LMArena WebDev: from an image | 1737 | 1285 | Claude Sonnet 5.5 |
| SciCode | 13.8% | Not measured | Only Claude Sonnet 5.5 measured |
| Neither model has a result on the other 11 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Pro | Leader |
|---|---|---|---|
| AA Intelligence Index | 56.0 | 16.1 | Claude Sonnet 5.5 |
| Epoch Capabilities Index | 166.2 | 145.1 | Claude Sonnet 5.5 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Pro | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 1.6 | Only Gemini 2.5 Pro measured |
| Design Arena: agents building web apps | 1305 | Not measured | Only Claude Sonnet 5.5 measured |
| Design Arena: agents building mobile apps | 1260 | Not measured | Only Claude Sonnet 5.5 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% | Not measured | Only Claude Sonnet 5.5 measured |
| Finance Agent (Vals AI) | 58.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Tax Agent Bench (Vals AI) | 42.0% | Not measured | Only Claude Sonnet 5.5 measured |
| Legal Research Bench (Vals AI) | 48.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Harvey's Legal Agent Benchmark (Vals AI) | 10.4% | Not measured | Only Claude Sonnet 5.5 measured |
| Excel Modeling Benchmark (Vals AI) | 75.7% | Not measured | Only Claude Sonnet 5.5 measured |
| BioMysteryBench (Vals AI) | 81.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Terminal-Bench-Science (Vals AI) | 47.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Vals Science Index | 59.1% | Not measured | Only Claude Sonnet 5.5 measured |
| τ²-Bench Telecom | Not measured | 54.1% | Only Gemini 2.5 Pro measured |
| APEX-Agents | 75.5% | Not measured | Only Claude Sonnet 5.5 measured |
| GDPval | Not measured | 23.3% | Only Gemini 2.5 Pro measured |
| DeepResearch Bench | Not measured | 41.5% | Only Gemini 2.5 Pro measured |
| SpireClimb | 1.3% | Not measured | Only Claude Sonnet 5.5 measured |
| Vending-Bench 2 | $11,165 | $574 | Claude Sonnet 5.5 |
| BrowseComp-Plus | Not measured | 29.5% | Only Gemini 2.5 Pro measured |
| Neither model has a result on the other 18 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index70
| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Pro | Leader |
|---|---|---|---|
| LiveBench reasoning | 91.6% | Not measured | Only Claude Sonnet 5.5 measured |
| MysteryMechanism (Vals AI) | 49.1% | Not measured | Only Claude Sonnet 5.5 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 84.4% | Only Gemini 2.5 Pro measured |
| Humanity's Last Exam (Artificial Analysis run) | 55.0% | 22.5% | Claude Sonnet 5.5 |
| GPQA Diamond (Epoch AI run) | 95.6% | 85.3% | Claude Sonnet 5.5 |
| ARC-AGI | Not measured | 41.0% | Only Gemini 2.5 Pro measured |
| ARC-AGI-2 | Not measured | 4.9% | Only Gemini 2.5 Pro measured |
| Chess puzzles | 59.0% | Not measured | Only Claude Sonnet 5.5 measured |
| Mystery game puzzles | 65.0% | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: hard prompts | 1494 | 1455 | Claude Sonnet 5.5 |
| LMArena Text: expert | 1531 | 1452 | Claude Sonnet 5.5 |
| LMArena Text: hard prompts in English | 1502 | 1453 | Claude Sonnet 5.5 |
| LMArena Vision: diagrams | 1329 | 1274 | Claude Sonnet 5.5 |
| LMArena Vision: homework | 1331 | 1281 | Claude Sonnet 5.5 |
| Kagi LLM Benchmark | Not measured | 70.3% | Only Gemini 2.5 Pro measured |
| Neither model has a result on the other 7 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Pro | Leader |
|---|---|---|---|
| AA Math Index | Not measured | 87.7 | Only Gemini 2.5 Pro measured |
| AIME 2025 (Artificial Analysis run) | Not measured | 87.7% | Only Gemini 2.5 Pro measured |
| OTIS Mock AIME | 100.0% | 84.7% | Claude Sonnet 5.5 |
| FrontierMath, tiers 1 to 3 | 88.8% | 24.6% | Claude Sonnet 5.5 |
| FrontierMath, tier 4 | 80.5% | 0.0% | Claude Sonnet 5.5 |
| ProofBench | 100.0% | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: math | 1497 | 1450 | Claude Sonnet 5.5 |
| LMArena Text: mathematical work | 1510 | 1454 | Claude Sonnet 5.5 |
| Neither model has a result on the other 5 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index41
| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Pro | Leader |
|---|---|---|---|
| CaseLaw (Vals AI) | Not measured | 63.9% | Only Gemini 2.5 Pro measured |
| CorpFin (Vals AI) | Not measured | 60.8% | Only Gemini 2.5 Pro measured |
| MortgageTax (Vals AI) | Not measured | 68.9% | Only Gemini 2.5 Pro measured |
| MedCode (Vals AI) | 52.9% | 50.6% | Claude Sonnet 5.5 |
| MMLU Pro (Artificial Analysis run) | Not measured | 86.2% | Only Gemini 2.5 Pro measured |
| SimpleQA Verified | 46.5% | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: science | 1483 | 1480 | Claude Sonnet 5.5 |
| LMArena Text: medicine and healthcare | 1464 | 1476 | Gemini 2.5 Pro |
| LMArena Text: legal and government | 1483 | 1480 | Claude Sonnet 5.5 |
| LMArena Text: business and finance | 1468 | 1439 | Claude Sonnet 5.5 |
| FACTS Benchmark Suite | Not measured | 61.5% | Only Gemini 2.5 Pro measured |
| Neither model has a result on the other 7 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Pro | Leader |
|---|---|---|---|
| Design Arena: websites | 1326 | 1167 | Claude Sonnet 5.5 |
| Design Arena: UI components | 1368 | 1137 | Claude Sonnet 5.5 |
| Design Arena: game dev | 1471 | 1111 | Claude Sonnet 5.5 |
| Design Arena: data viz | 1392 | 1222 | Claude Sonnet 5.5 |
| Design Arena: 3D | 1445 | 1080 | Claude Sonnet 5.5 |
| Design Arena: all code categories | 1364 | 1152 | Claude Sonnet 5.5 |
| LiveBench design | 85.0% | Not measured | Only Claude Sonnet 5.5 measured |
| Neither model has a result on the other 2 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index193
| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 Pro | 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% | Not measured | Only Claude Sonnet 5.5 measured |
| SAGE (Vals AI) | 51.8% | 41.9% | Claude Sonnet 5.5 |
| MedScribe (Vals AI) | 91.1% | 73.5% | Claude Sonnet 5.5 |
| IFBench | Not measured | 48.7% | Only Gemini 2.5 Pro measured |
| Long context reasoning (AA-LCR) | 82.7% | 69.0% | Claude Sonnet 5.5 |
| DTBench | 97.3% | 82.4% | Claude Sonnet 5.5 |
| LMCA | 68.3% | 34.8% | Claude Sonnet 5.5 |
| Creative writing (Lech Mazur) | Not measured | 83.8% | Only Gemini 2.5 Pro measured |
| Furniture assembly | 75.0% | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text | 1473 | 1458 | Claude Sonnet 5.5 |
| LMArena Text: instruction following | 1492 | 1437 | Claude Sonnet 5.5 |
| LMArena Text: creative writing | 1467 | 1454 | Claude Sonnet 5.5 |
| LMArena Vision | 1287 | 1263 | Claude Sonnet 5.5 |
| LMArena Text: English | 1484 | 1458 | Claude Sonnet 5.5 |
| LMArena Text: non-English | 1456 | 1452 | Claude Sonnet 5.5 |
| LMArena Text: Chinese | 1535 | 1507 | Claude Sonnet 5.5 |
| LMArena Text: German | Not measured | 1487 | Only Gemini 2.5 Pro measured |
| LMArena Text: Japanese | Not measured | 1461 | Only Gemini 2.5 Pro measured |
| LMArena Text: Korean | Not measured | 1434 | Only Gemini 2.5 Pro measured |
| LMArena Text: French | 1499 | 1473 | Claude Sonnet 5.5 |
| LMArena Text: Spanish | 1451 | 1474 | Gemini 2.5 Pro |
| LMArena Text: Russian | 1454 | 1461 | Gemini 2.5 Pro |
| LMArena Text: Polish | Not measured | 1479 | Only Gemini 2.5 Pro measured |
| LMArena Text: multi-turn | 1465 | 1453 | Claude Sonnet 5.5 |
| LMArena Text: longer queries | 1495 | 1449 | Claude Sonnet 5.5 |
| LMArena Text: writing and language | 1474 | 1454 | Claude Sonnet 5.5 |
| LMArena Text: entertainment and media | 1461 | 1441 | Claude Sonnet 5.5 |
| LMArena Vision: English | 1289 | 1261 | Claude Sonnet 5.5 |
| LMArena Vision: Chinese | Not measured | 1300 | Only Gemini 2.5 Pro measured |
| LMArena Vision: reading text | 1297 | 1270 | Claude Sonnet 5.5 |
| LMArena Vision: humor | Not measured | 1262 | Only Gemini 2.5 Pro measured |
| LMArena Vision: captioning | Not measured | 1304 | Only Gemini 2.5 Pro measured |
| LMArena Vision: recognizing things | Not measured | 1283 | Only Gemini 2.5 Pro measured |
| LMArena Vision: creative writing | 1242 | 1265 | Gemini 2.5 Pro |
| LMArena Document | Not measured | 1421 | Only Gemini 2.5 Pro measured |
| Neither model has a result on the other 9 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Sonnet 5.5 | Gemini 2.5 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
Gemini 2.5 Pro costs less
Repository review
50K input + 3K output tokens
Gemini 2.5 Pro costs less
Agent loop
200K input + 10K output tokens
Gemini 2.5 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 | Anthropic Claude Sonnet 5.5 | Google Gemini 2.5 Pro |
|---|---|---|
| Maker | Anthropic | |
| Weights | No public weights listed | No public weights listed |
| Released | September 28, 2026 | June 17, 2025 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $2.00 | $1.25 |
| Output $/Mtok | $10.00 | $10.00 |
| Coding index | 87.3 | 19.1 |
| Independent measurements behind it | 5 | 3 |
| Cost per solved task | Not computable | $0.64 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Sonnet 5.5 better than Gemini 2.5 Pro for coding?
Pick Claude Sonnet 5.5 for coding: it scores 87.3 on the Vibe Coding Index against 19.1 for Gemini 2.5 Pro. Pick Gemini 2.5 Pro for a larger context window (1.05M against 1M tokens) and work measured by LMArena Text: medicine and healthcare or LMArena Text: Spanish, where it leads.
Which is cheaper, Claude Sonnet 5.5 or Gemini 2.5 Pro?
Claude Sonnet 5.5 costs $2.00 per million input tokens and $10.00 per million output tokens; Gemini 2.5 Pro costs $1.25 and $10.00. Cost per solved task is known for Gemini 2.5 Pro only.
Which has the bigger context window, Claude Sonnet 5.5 or Gemini 2.5 Pro?
Gemini 2.5 Pro, with 1.05M tokens against 1M.
How many benchmarks is the Claude Sonnet 5.5 vs Gemini 2.5 Pro comparison based on?
55 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 2.5 Pro's on 3. Where only one model has a result, the page says so instead of naming a winner.