Claude Sonnet 4.5
VS
Gemini 3.5 Flash
Claude Sonnet 4.5 vs Gemini 3.5 Flash: which wins at real work?
22 task areas · same graded test runs · rank comparison only, so 0–100 and Elo collections never mix raw scores.
Gemini 3.5 Flash wins 13 of 22 task areas we tested; Claude Sonnet 4.5 takes 9. Gemini 3.5 Flash costs 1.7× less per token ($10.5 vs $18 per 1M).
Gemini 3.5 Flash costs 1.7× less per token ($10.5 vs $18 per 1M).
Task by task
| Task area | Claude Sonnet 4.5 | Gemini 3.5 Flash | Winner |
|---|---|---|---|
| Chef / Home Cooking |
#80
/ 126
Usable
|
#24
/ 126
Usable
|
Gemini 3.5 Flash |
| Structured Output |
#80
/ 113
Strong
|
#35
/ 113
Excellent
|
Gemini 3.5 Flash |
| AI Strategy |
#67
/ 126
Strong
|
#23
/ 126
Strong
|
Gemini 3.5 Flash |
| Training & Education |
#51
/ 110
Excellent
|
#7
/ 110
Excellent
|
Gemini 3.5 Flash |
| Creative & Comedy | #66 / 110 | #27 / 110 | Gemini 3.5 Flash |
| Product & Project Management |
#71
/ 110
Strong
|
#33
/ 110
Strong
|
Gemini 3.5 Flash |
| Coding |
#62
/ 115
Strong
|
#28
/ 115
Strong
|
Gemini 3.5 Flash |
| Customer Support |
#43
/ 113
Strong
|
#12
/ 113
Strong
|
Gemini 3.5 Flash |
| Content & Brand |
#74
/ 124
Usable
|
#46
/ 124
Strong
|
Gemini 3.5 Flash |
| Presentations & Decks |
#43
/ 110
Excellent
|
#17
/ 110
Excellent
|
Gemini 3.5 Flash |
| Research & Competitive Analysis |
#39
/ 110
Strong
|
#65
/ 110
Usable
|
Claude Sonnet 4.5 |
| Frontend & Landing Pages |
#29
/ 109
Needs editing
|
#4
/ 109
Usable
|
Gemini 3.5 Flash |
| RAG, Safety & Grounding |
#39
/ 113
Excellent
|
#15
/ 113
Excellent
|
Gemini 3.5 Flash |
| Sales |
#10
/ 110
Strong
|
#33
/ 110
Strong
|
Claude Sonnet 4.5 |
| Knowledge & Docs |
#28
/ 110
Strong
|
#44
/ 110
Strong
|
Claude Sonnet 4.5 |
| Summarization & Meeting Notes |
#2
/ 110
Excellent
|
#17
/ 110
Excellent
|
Claude Sonnet 4.5 |
| Investor & Pitch |
#42
/ 66
Usable
|
#56
/ 66
Usable
|
Claude Sonnet 4.5 |
| Executive Assistant |
#31
/ 112
Strong
|
#19
/ 112
Strong
|
Gemini 3.5 Flash |
| Landing Pages |
#30
/ 72
Strong
|
#40
/ 72
Strong
|
Claude Sonnet 4.5 |
| Translation & Localization |
#25
/ 110
Excellent
|
#30
/ 110
Excellent
|
Claude Sonnet 4.5 |
| Legal & HR |
#69
/ 110
Strong
|
#73
/ 110
Strong
|
Claude Sonnet 4.5 |
| Data & Analytics |
#33
/ 110
Excellent
|
#34
/ 110
Excellent
|
Claude Sonnet 4.5 |
Rank = position among every model config we tested in that task area (lower is better). Sorted by biggest gap first.
Frequently asked
Is Claude Sonnet 4.5 better than Gemini 3.5 Flash?
Across 22 task areas we benchmarked, Gemini 3.5 Flash ranks higher in 13 and Claude Sonnet 4.5 in 9.
Which is cheaper, Claude Sonnet 4.5 or Gemini 3.5 Flash?
Gemini 3.5 Flash costs 1.7× less per token ($10.5 vs $18 per 1M).
What is Claude Sonnet 4.5 better at?
Claude Sonnet 4.5 out-ranks Gemini 3.5 Flash at Research & Competitive Analysis, Sales, Knowledge & Docs.
What is Gemini 3.5 Flash better at?
Gemini 3.5 Flash out-ranks Claude Sonnet 4.5 at Chef / Home Cooking, Structured Output, AI Strategy.
More comparisons
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Prompt × model results
12 test cases · 3 evals