Model comparison
Claude Sonnet 4.5 vs Gemini 3 Flash
Head-to-head evidence from 5 shared benchmark results across 3 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude Sonnet 4.5 #96 (Estimated); Gemini 3 Flash #49 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Sonnet 4.5 and Gemini 3 Flash share 5 comparable benchmark results. 1 of 8 categories are comparable. 7 results are unique to Claude Sonnet 4.5; 14 to Gemini 3 Flash.
Updated July 22, 2026- Shared results
- 5
- Claude Sonnet 4.5 only
- 7
- Gemini 3 Flash only
- 14
- Comparable categories
- 1 / 8
Pick Gemini 3 Flash if you want the stronger benchmark profile. Claude Sonnet 4.5 only becomes the better choice if its workflow or ecosystem matters more than the raw scoreboard.
Confidence note. This is a partial-evidence comparison with 5 shared benchmark results across 3 evidence categories; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
Gemini 3 Flash is clearly ahead on the BenchAlign aggregate, 60.49 to 53.61. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Gemini 3 Flash's sharpest advantage is in mathematics, where it averages 27.8 against 11.2. The single biggest benchmark swing on the page is FrontierMath v2 (Tiers 1-3), 13.495% to 35.640%.
Claude Sonnet 4.5 is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $0.50 input / $3.00 output per 1M tokens for Gemini 3 Flash. That is roughly 5.0x on output cost alone. Gemini 3 Flash gives you the larger context window at 1M, compared with 200K for Claude Sonnet 4.5.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | Claude Sonnet 4.5 | Δ | Gemini 3 Flash |
|---|---|---|---|
| Math | Claude Sonnet 4.511.2 | Margin→ 16.6 | Gemini 3 Flash27.8 |
| Agentic | Claude Sonnet 4.555.4 | MarginNo overlap | Gemini 3 FlashNot measured |
| Coding | Claude Sonnet 4.577.2 | MarginNo overlap | Gemini 3 FlashNot measured |
| Reasoning | Claude Sonnet 4.513.6 | MarginNo overlap | Gemini 3 FlashNot measured |
| Knowledge | Claude Sonnet 4.583.4 | MarginNo overlap | Gemini 3 FlashNot measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
FrontierMath v2 (Tiers 1-3)
MathA 13.495%B 35.640%Winner: Gemini 3 FlashΔ 22.1FrontierMath v2 (Tiers 1-3): Claude Sonnet 4.5 scored 13.495%; Gemini 3 Flash scored 35.640%. Gemini 3 Flash wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Sonnet 4.5 | Gemini 3 Flash | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Sonnet 4.5$3 input / $15 output | Gemini 3 Flash$0.5 input / $3 output | Gemini 3 Flash has the lower combined listed price. |
| Generation speedtokens per second | Claude Sonnet 4.5Not available | Gemini 3 Flash159 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Sonnet 4.5Not available | Gemini 3 Flash1.19 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Sonnet 4.5200K | Gemini 3 Flash1M | Gemini 3 Flash lists the larger context window. |
Benchmark Deep Dive
Agentic7 benchmarks
| Benchmark | Claude Sonnet 4.5 | Gemini 3 Flash | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 50% | — | Not comparable |
| OSWorld-VerifiedSource | 61.4% | — | Not comparable |
| VITA-BenchSource | 17.0% | — | Not comparable |
| Gert LabsSource | 48.51% | 56.63% | Gemini 3 Flash leads |
| JobBenchSource | 27.7% | 11.4% | Claude Sonnet 4.5 leads |
| Claw-EvalSource | — | 49.2% | Not comparable |
| τ²-bench resultsSource | — | 43.3% | Not comparable |
Coding3 benchmarks
Reasoning3 benchmarks
Knowledge7 benchmarks
| Benchmark | Claude Sonnet 4.5 | Gemini 3 Flash | Result |
|---|---|---|---|
| GPQASource | 83.4% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | — | 27.4% | Not comparable |
| AA-GPQA DiamondSource | — | 81.2% | Not comparable |
| AA-HLESource | — | 14.1% | Not comparable |
| AA-Omniscience IndexSource | — | -3.6% | Not comparable |
| AA-Omniscience AccuracySource | — | 45.5% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 90.2% | Not comparable |
MathGemini 3 Flash wins3 benchmarks
Multimodal2 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude Sonnet 4.5 | Gemini 3 Flash | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 55.1% | Not comparable |
Frequently Asked Questions (2)
Which is better, Claude Sonnet 4.5 or Gemini 3 Flash?
Gemini 3 Flash is ahead on BenchLM's BenchAlign leaderboard, 60.49 to 53.61. The biggest single separator in this matchup is FrontierMath v2 (Tiers 1-3), where the scores are 13.495% and 35.640%.
Which is better for math, Claude Sonnet 4.5 or Gemini 3 Flash?
Gemini 3 Flash has the edge for math in this comparison, averaging 27.8 versus 11.2. Inside this category, FrontierMath v2 (Tiers 1-3) is the benchmark that creates the most daylight between them.
Related Comparisons
Choose a model with this week’s evidence
Join 2,000+ readers for ranking moves, pricing changes, and the claims that still need proof.
One email each week. Unsubscribe anytime.