Claude Sonnet 4.5 vs Gemini 3.5 Flash Lite
Gemini 3.5 Flash Lite leads Claude Sonnet 4.5 on coding, 49.0 to 39.5 on the Vibe Coding Index, and Gemini 3.5 Flash Lite costs 6.0x less per output token ($2.50 vs $15.00 per million). Updated October 22, 2026; 60 benchmarks have a result for both.
Claude Sonnet 4.5 or Gemini 3.5 Flash Lite: which to pick
Pick Gemini 3.5 Flash Lite for coding: it scores 49.0 on the Vibe Coding Index against 39.5 for Claude Sonnet 4.5.
Pick Claude Sonnet 4.5 for work measured by AA Coding Index or WeirdML, where it leads.
- Shared results
- 60
- Claude Sonnet 4.5 only
- 35
- Gemini 3.5 Flash Lite only
- 25
- 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
Gemini 3.5 Flash Lite
Gemini 3.5 Flash Lite scores 49.0 against 39.5.
3 benchmarks behind each score
Intelligence
AA Intelligence Index
Gemini 3.5 Flash Lite
Gemini 3.5 Flash Lite leads, 22.2 against 20.7.
Same board, both measured
Agentic work
AA Agentic Index
Claude Sonnet 4.5
Claude Sonnet 4.5 leads, 15.8 against 14.3.
Same board, both measured
Reasoning
GPQA Diamond
Gemini 3.5 Flash Lite
Gemini 3.5 Flash Lite leads, 83.8% 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
Claude Sonnet 4.5
Claude Sonnet 4.5 leads, 87.4% against 85.8%.
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
Gemini 3.5 Flash Lite
Gemini 3.5 Flash Lite takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Gemini 3.5 Flash Lite
Claude Sonnet 4.5 $0.011, Gemini 3.5 Flash Lite $0.0015 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Gemini 3.5 Flash Lite
Claude Sonnet 4.5 $1.16, Gemini 3.5 Flash Lite $0.41.
Published attempt cost and pass rate
At a glance
- Coding index
- Claude Sonnet 4.5 39.5 from 3 benchmarks, Gemini 3.5 Flash Lite 49.0 from 3 benchmarks.
- Widest category
- Coding, 6.2 points apart on average over 9 shared benchmarks.
- Widest single gap
- Vibe Code Bench (Vals AI): Claude Sonnet 4.5 22.6% against Gemini 3.5 Flash Lite 37.2%, 14.5 points apart on a 0 to 100 scale.
- Output price
- Claude Sonnet 4.5 $15.00 against Gemini 3.5 Flash Lite $2.50 per million output tokens, 6.0x apart.
- Context window
- Claude Sonnet 4.5 takes 1M tokens, Gemini 3.5 Flash Lite 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 | Gemini 3.5 Flash Lite | Ties |
|---|---|---|---|---|
| Coding | 4 | 5 | ||
| Intelligence | 1 | 1 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 5 | 5 | ||
| Math | 5 | 1 | ||
| Knowledge | 8 | 3 | ||
| General | 12 | 9 | ||
| All shared boards | 36 | 24 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index45
| Benchmark | Claude Sonnet 4.5 | Gemini 3.5 Flash Lite | 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 |
| LMArena WebDev | 1394 | 1435 | Gemini 3.5 Flash Lite |
| AA Coding Index | 52.1 | 49.3 | Claude Sonnet 4.5 |
| LiveCodeBench (Vals AI) | 73.0% | 79.0% | Gemini 3.5 Flash Lite |
| SWE-bench Verified (Vals AI) | 70.0% | 75.0% | Gemini 3.5 Flash Lite |
| Vibe Code Bench (Vals AI) | 22.6% | 37.2% | Gemini 3.5 Flash Lite |
| Code migration (Vals AI) | Not measured | 6.2% | Only Gemini 3.5 Flash Lite measured |
| ProgramBench (Vals AI) | Not measured | 0.0% | Only Gemini 3.5 Flash Lite measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 50.2% | Only Gemini 3.5 Flash Lite measured |
| CyberBench (Vals AI) | Not measured | 59.1% | Only Gemini 3.5 Flash Lite measured |
| SciCode | Not measured | 41.3% | Only Gemini 3.5 Flash Lite 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% | 39.0% | Claude Sonnet 4.5 |
| Cybench | 60.0% | Not measured | Only Claude Sonnet 4.5 measured |
| ALE-Bench | Not measured | 765.3 | Only Gemini 3.5 Flash Lite measured |
| LMArena Text: coding | 1488 | 1453 | Claude Sonnet 4.5 |
| LMArena Text: software and IT | 1473 | 1451 | Claude Sonnet 4.5 |
| LMArena WebDev: React | 1386 | 1408 | Gemini 3.5 Flash Lite |
| LMArena WebDev: HTML | 1399 | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena WebDev: from an image | Not measured | 1448 | Only Gemini 3.5 Flash Lite measured |
| SciCode | Not measured | 6.2% | Only Gemini 3.5 Flash Lite measured |
| Neither model has a result on the other 16 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index11
| Benchmark | Claude Sonnet 4.5 | Gemini 3.5 Flash Lite | Leader |
|---|---|---|---|
| AA Intelligence Index | 20.7 | 22.2 | Gemini 3.5 Flash Lite |
| Epoch Capabilities Index | 146.7 | 144.9 | Claude Sonnet 4.5 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Sonnet 4.5 | Gemini 3.5 Flash Lite | Leader |
|---|---|---|---|
| AA Agentic Index | 15.8 | 14.3 | Claude Sonnet 4.5 |
| 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 |
| Finance Agent (Vals AI) | Not measured | 47.4% | Only Gemini 3.5 Flash Lite measured |
| Tax Agent Bench (Vals AI) | Not measured | 7.2% | Only Gemini 3.5 Flash Lite measured |
| Legal Research Bench (Vals AI) | Not measured | 13.9% | Only Gemini 3.5 Flash Lite measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 43.2% | Only Gemini 3.5 Flash Lite measured |
| APEX-Agents | Not measured | 29.3% | Only Gemini 3.5 Flash Lite 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 |
| 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 25 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index55
| Benchmark | Claude Sonnet 4.5 | Gemini 3.5 Flash Lite | Leader |
|---|---|---|---|
| GPQA Diamond | 81.6% | 83.8% | Gemini 3.5 Flash Lite |
| MMMU Pro (Vals AI) | 79.3% | 83.6% | Gemini 3.5 Flash Lite |
| GPQA Diamond (Artificial Analysis run) | Not measured | 83.8% | Only Gemini 3.5 Flash Lite measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 18.8% | Only Gemini 3.5 Flash Lite measured |
| GPQA Diamond (Epoch AI run) | 82.3% | 83.3% | Gemini 3.5 Flash Lite |
| ARC-AGI | 63.7% | 53.5% | Claude Sonnet 4.5 |
| ARC-AGI-2 | 13.6% | 10.3% | Claude Sonnet 4.5 |
| SimpleBench | 54.3% | Not measured | Only Claude Sonnet 4.5 measured |
| Chess puzzles | 10.0% | 21.0% | Gemini 3.5 Flash Lite |
| Mystery game puzzles | 17.0% | 19.0% | Gemini 3.5 Flash Lite |
| EBR-bench | 2.4% | Not measured | Only Claude Sonnet 4.5 measured |
| VPCT | 39.8% | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena Text: hard prompts | 1462 | 1441 | Claude Sonnet 4.5 |
| LMArena Text: expert | 1483 | 1434 | Claude Sonnet 4.5 |
| LMArena Text: hard prompts in English | 1471 | 1440 | Claude Sonnet 4.5 |
| LMArena Vision: diagrams | Not measured | 1284 | Only Gemini 3.5 Flash Lite measured |
| LMArena Vision: homework | Not measured | 1291 | Only Gemini 3.5 Flash Lite measured |
| Kagi LLM Benchmark | 57.9% | Not measured | Only Claude Sonnet 4.5 measured |
| Neither model has a result on the other 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index51
| Benchmark | Claude Sonnet 4.5 | Gemini 3.5 Flash Lite | 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% | 71.1% | Claude Sonnet 4.5 |
| FrontierMath, tiers 1 to 3 | 23.9% | 26.0% | Gemini 3.5 Flash Lite |
| FrontierMath, tier 4 | 2.4% | 0.0% | Claude Sonnet 4.5 |
| ProofBench | 19.0% | 13.0% | Claude Sonnet 4.5 |
| MATH level 5 | 97.7% | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena Text: math | 1449 | 1434 | Claude Sonnet 4.5 |
| LMArena Text: mathematical work | 1462 | 1433 | Claude Sonnet 4.5 |
| Neither model has a result on the other 4 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index83
| Benchmark | Claude Sonnet 4.5 | Gemini 3.5 Flash Lite | Leader |
|---|---|---|---|
| MMLU Pro | 87.4% | 85.8% | Claude Sonnet 4.5 |
| LegalBench (Vals AI) | 84.1% | 84.1% | Claude Sonnet 4.5 |
| CaseLaw (Vals AI) | 62.2% | Not measured | Only Claude Sonnet 4.5 measured |
| CorpFin (Vals AI) | 62.0% | 60.7% | Claude Sonnet 4.5 |
| TaxEval (Vals AI) | 73.3% | 72.6% | Claude Sonnet 4.5 |
| MortgageTax (Vals AI) | 64.0% | 68.7% | Gemini 3.5 Flash Lite |
| MedQA (Vals AI) | 94.7% | Not measured | Only Claude Sonnet 4.5 measured |
| MedCode (Vals AI) | 44.1% | 43.5% | Claude Sonnet 4.5 |
| SimpleQA Verified | 30.7% | Not measured | Only Claude Sonnet 4.5 measured |
| LMArena Text: science | 1448 | 1451 | Gemini 3.5 Flash Lite |
| LMArena Text: medicine and healthcare | 1444 | 1438 | Claude Sonnet 4.5 |
| LMArena Text: legal and government | 1451 | 1431 | Claude Sonnet 4.5 |
| LMArena Text: business and finance | 1440 | 1423 | Claude Sonnet 4.5 |
| FACTS Benchmark Suite | 40.6% | 53.5% | Gemini 3.5 Flash Lite |
| Neither model has a result on the other 4 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Claude Sonnet 4.5 | Gemini 3.5 Flash Lite | 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 index129
| Benchmark | Claude Sonnet 4.5 | Gemini 3.5 Flash Lite | Leader |
|---|---|---|---|
| Public Benefits Bench (Vals AI) | Not measured | 51.8% | Only Gemini 3.5 Flash Lite measured |
| SAGE (Vals AI) | 36.1% | 47.3% | Gemini 3.5 Flash Lite |
| MedScribe (Vals AI) | 84.5% | 70.9% | Claude Sonnet 4.5 |
| Long context reasoning (AA-LCR) | Not measured | 76.0% | Only Gemini 3.5 Flash Lite measured |
| DTBench | 83.2% | 83.5% | Gemini 3.5 Flash Lite |
| LMCA | 38.8% | 37.6% | Claude Sonnet 4.5 |
| LMArena Text | 1438 | 1435 | Claude Sonnet 4.5 |
| LMArena Text: instruction following | 1459 | 1419 | Claude Sonnet 4.5 |
| LMArena Text: creative writing | 1442 | 1421 | Claude Sonnet 4.5 |
| LMArena Vision | Not measured | 1269 | Only Gemini 3.5 Flash Lite measured |
| LMArena Text: English | 1450 | 1438 | Claude Sonnet 4.5 |
| LMArena Text: non-English | 1425 | 1427 | Gemini 3.5 Flash Lite |
| LMArena Text: Chinese | 1460 | 1468 | Gemini 3.5 Flash Lite |
| LMArena Text: German | 1427 | 1454 | Gemini 3.5 Flash Lite |
| LMArena Text: Japanese | 1390 | 1426 | Gemini 3.5 Flash Lite |
| LMArena Text: Korean | 1402 | 1407 | Gemini 3.5 Flash Lite |
| LMArena Text: French | 1459 | 1451 | Claude Sonnet 4.5 |
| LMArena Text: Spanish | 1458 | 1441 | Claude Sonnet 4.5 |
| LMArena Text: Russian | 1437 | 1443 | Gemini 3.5 Flash Lite |
| LMArena Text: Polish | 1423 | 1437 | Gemini 3.5 Flash Lite |
| LMArena Text: multi-turn | 1465 | 1445 | Claude Sonnet 4.5 |
| LMArena Text: longer queries | 1475 | 1435 | Claude Sonnet 4.5 |
| LMArena Text: writing and language | 1442 | 1428 | Claude Sonnet 4.5 |
| LMArena Text: entertainment and media | 1428 | 1414 | Claude Sonnet 4.5 |
| LMArena Vision: English | Not measured | 1269 | Only Gemini 3.5 Flash Lite measured |
| LMArena Vision: Chinese | Not measured | 1311 | Only Gemini 3.5 Flash Lite measured |
| LMArena Vision: reading text | Not measured | 1280 | Only Gemini 3.5 Flash Lite measured |
| LMArena Vision: humor | Not measured | 1287 | Only Gemini 3.5 Flash Lite measured |
| LMArena Vision: creative writing | Not measured | 1260 | Only Gemini 3.5 Flash Lite measured |
| LMArena Document | 1450 | Not measured | Only Claude Sonnet 4.5 measured |
| Neither model has a result on the other 16 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Sonnet 4.5 | Gemini 3.5 Flash Lite | 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 3.5 Flash Lite costs less
Repository review
50K input + 3K output tokens
Gemini 3.5 Flash Lite costs less
Agent loop
200K input + 10K output tokens
Gemini 3.5 Flash Lite 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 | Google Gemini 3.5 Flash Lite |
|---|---|---|
| Maker | Anthropic | |
| Weights | No public weights listed | No public weights listed |
| Released | September 29, 2025 | July 21, 2026 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $3.00 | $0.30 |
| Output $/Mtok | $15.00 | $2.50 |
| Coding index | 39.5 | 49.0 |
| Independent measurements behind it | 3 | 3 |
| Cost per solved task | $1.16 | $0.41 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Sonnet 4.5 better than Gemini 3.5 Flash Lite for coding?
Pick Gemini 3.5 Flash Lite for coding: it scores 49.0 on the Vibe Coding Index against 39.5 for Claude Sonnet 4.5. Pick Claude Sonnet 4.5 for work measured by AA Coding Index or WeirdML, where it leads.
Which is cheaper, Claude Sonnet 4.5 or Gemini 3.5 Flash Lite?
Claude Sonnet 4.5 costs $3.00 per million input tokens and $15.00 per million output tokens; Gemini 3.5 Flash Lite costs $0.30 and $2.50. Per solved SWE-bench Verified task, Claude Sonnet 4.5 costs $1.16 and Gemini 3.5 Flash Lite $0.41.
Which has the bigger context window, Claude Sonnet 4.5 or Gemini 3.5 Flash Lite?
Gemini 3.5 Flash Lite, with 1.05M tokens against 1M.
How many benchmarks is the Claude Sonnet 4.5 vs Gemini 3.5 Flash Lite comparison based on?
60 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 Gemini 3.5 Flash Lite's on 3. Where only one model has a result, the page says so instead of naming a winner.