Model comparison
Gemini 1.5 Pro 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: Gemini 1.5 Pro #185 (Supported); Gemini 3 Flash #49 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Gemini 1.5 Pro and Gemini 3 Flash share 5 comparable benchmark results. 0 of 8 categories are comparable. 1 result is unique to Gemini 1.5 Pro; 14 to Gemini 3 Flash.
Updated July 20, 2026- Shared results
- 5
- Gemini 1.5 Pro only
- 1
- Gemini 3 Flash only
- 14
- Comparable categories
- 0 / 8
Benchmark data for Gemini 1.5 Pro and Gemini 3 Flash is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 5 shared benchmark results across 3 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
Gemini 1.5 Pro is priced at $1.25 input / $5.00 output per 1M tokens, versus $0.50 input / $3.00 output per 1M tokens for Gemini 3 Flash. Gemini 1.5 Pro has the larger context window at 2M, compared with 1M for Gemini 3 Flash.
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 | Gemini 1.5 Pro | Δ | Gemini 3 Flash |
|---|---|---|---|
| Math | Gemini 1.5 ProNot measured | MarginNo overlap | Gemini 3 Flash27.8 |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Gemini 1.5 Pro | Gemini 3 Flash | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Gemini 1.5 Pro$1.25 input / $5 output | Gemini 3 Flash$0.5 input / $3 output | Gemini 3 Flash has the lower combined listed price. |
| Generation speedtokens per second | Gemini 1.5 ProNot available | Gemini 3 Flash159 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Gemini 1.5 ProNot available | Gemini 3 Flash1.19 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Gemini 1.5 Pro2M | Gemini 3 Flash1M | Gemini 1.5 Pro lists the larger context window. |
Benchmark Deep Dive
Agentic4 benchmarks
Coding3 benchmarks
Reasoning2 benchmarks
Knowledge6 benchmarks
| Benchmark | Gemini 1.5 Pro | Gemini 3 Flash | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 10.0% | 27.4% | Gemini 3 Flash leads |
| AA-GPQA DiamondSource | 58.9% | 81.2% | Gemini 3 Flash leads |
| AA-HLESource | 4.9% | 14.1% | Gemini 3 Flash leads |
| AA-Omniscience IndexSource | — | -3.6% | Not comparable |
| AA-Omniscience AccuracySource | — | 45.5% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 90.2% | Not comparable |
Math2 benchmarks
Multimodal2 benchmarks
Inst. Following1 benchmarks
| Benchmark | Gemini 1.5 Pro | Gemini 3 Flash | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 55.1% | Not comparable |
Frequently Asked Questions (3)
Can I compare Gemini 1.5 Pro and Gemini 3 Flash on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
What data is available for Gemini 1.5 Pro and Gemini 3 Flash today?
Gemini 1.5 Pro: $1.25 input / $5.00 output per 1M tokens Gemini 3 Flash: $0.50 input / $3.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
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