Claude Sonnet 5 vs Gemini 3 Flash Preview: 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.
Claude Sonnet 5 wins 14 of 22 task areas we tested; Gemini 3 Flash Preview takes 8. Gemini 3 Flash Preview costs 3.4× less per token ($3.5 vs $12 per 1M).
Gemini 3 Flash Preview costs 3.4× less per token ($3.5 vs $12 per 1M).
Task by task
| Task area | Claude Sonnet 5 | Gemini 3 Flash Preview | Winner |
|---|---|---|---|
| RAG, Safety & Grounding |
#86
/ 113
Excellent
|
#13
/ 113
Excellent
|
Gemini 3 Flash Preview |
| Frontend & Landing Pages |
#57
/ 109
Needs editing
|
#1
/ 109
Usable
|
Gemini 3 Flash Preview |
| Research & Competitive Analysis |
#15
/ 110
Excellent
|
#71
/ 110
Usable
|
Claude Sonnet 5 |
| Training & Education |
#52
/ 110
Excellent
|
#11
/ 110
Excellent
|
Gemini 3 Flash Preview |
| AI Strategy |
#2
/ 126
Strong
|
#38
/ 126
Strong
|
Claude Sonnet 5 |
| Structured Output |
#69
/ 113
Strong
|
#34
/ 113
Excellent
|
Gemini 3 Flash Preview |
| Data & Analytics |
#16
/ 110
Excellent
|
#47
/ 110
Excellent
|
Claude Sonnet 5 |
| Knowledge & Docs |
#18
/ 110
Strong
|
#49
/ 110
Usable
|
Claude Sonnet 5 |
| Presentations & Decks |
#22
/ 110
Excellent
|
#52
/ 110
Excellent
|
Claude Sonnet 5 |
| Content & Brand |
#67
/ 124
Strong
|
#39
/ 124
Strong
|
Gemini 3 Flash Preview |
| Creative & Comedy | #79 / 110 | #51 / 110 | Gemini 3 Flash Preview |
| Translation & Localization |
#41
/ 110
Excellent
|
#67
/ 110
Excellent
|
Claude Sonnet 5 |
| Customer Support |
#57
/ 113
Strong
|
#34
/ 113
Strong
|
Gemini 3 Flash Preview |
| Landing Pages |
#12
/ 72
Strong
|
#35
/ 72
Strong
|
Claude Sonnet 5 |
| Executive Assistant |
#72
/ 112
Strong
|
#92
/ 112
Usable
|
Claude Sonnet 5 |
| Sales |
#16
/ 110
Strong
|
#35
/ 110
Usable
|
Claude Sonnet 5 |
| Coding |
#6
/ 115
Excellent
|
#22
/ 115
Strong
|
Claude Sonnet 5 |
| Chef / Home Cooking |
#28
/ 126
Usable
|
#39
/ 126
Usable
|
Claude Sonnet 5 |
| Legal & HR |
#57
/ 110
Excellent
|
#47
/ 110
Excellent
|
Gemini 3 Flash Preview |
| Investor & Pitch |
#39
/ 66
Usable
|
#47
/ 66
Usable
|
Claude Sonnet 5 |
| Product & Project Management |
#61
/ 110
Strong
|
#69
/ 110
Strong
|
Claude Sonnet 5 |
| Summarization & Meeting Notes |
#58
/ 110
Excellent
|
#61
/ 110
Excellent
|
Claude Sonnet 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 5 better than Gemini 3 Flash Preview?
Across 22 task areas we benchmarked, Claude Sonnet 5 ranks higher in 14 and Gemini 3 Flash Preview in 8.
Which is cheaper, Claude Sonnet 5 or Gemini 3 Flash Preview?
Gemini 3 Flash Preview costs 3.4× less per token ($3.5 vs $12 per 1M).
What is Claude Sonnet 5 better at?
Claude Sonnet 5 out-ranks Gemini 3 Flash Preview at Research & Competitive Analysis, AI Strategy, Data & Analytics.
What is Gemini 3 Flash Preview better at?
Gemini 3 Flash Preview out-ranks Claude Sonnet 5 at RAG, Safety & Grounding, Frontend & Landing Pages, Training & Education.
More comparisons
This page is Spring Prompt, running in public
We just did this for every model. Do it for your prompt.
The rankings above come from running real tasks through real models and scoring every output. Spring Prompt is that same engine — pointed at your prompt, your test cases, and your definition of good.
- Generate test cases from your prompt — no eval set required to start.
- Compare models side by side with quality, cost and latency in one matrix.
- Optimise the winner until the scores say it's ready to ship.
Prompt × model results
12 test cases · 3 evals