Model comparison
Gemini 2.5 Pro vs Gemini 3.5 Flash-Lite
Head-to-head evidence from 14 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Gemini 2.5 Pro #70 (Supported); Gemini 3.5 Flash-Lite unranked (Not scored). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Gemini 2.5 Pro and Gemini 3.5 Flash-Lite share 14 comparable benchmark results. 1 of 8 categories are comparable. 10 results are unique to Gemini 2.5 Pro; 7 to Gemini 3.5 Flash-Lite.
Updated July 21, 2026- Shared results
- 14
- Gemini 2.5 Pro only
- 10
- Gemini 3.5 Flash-Lite only
- 7
- Comparable categories
- 1 / 8
Treat this as a split decision. Gemini 2.5 Pro makes more sense if coding is the priority or you would rather avoid the extra latency and token burn of a reasoning model; Gemini 3.5 Flash-Lite is the better fit if you want the cheaper token bill or you want the stronger reasoning-first profile.
Confidence note. This is a partial-evidence comparison with 14 shared benchmark results across 5 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 2.5 Pro and Gemini 3.5 Flash-Lite finish on the same BenchAlign overall score, so this is less about a single winner and more about where the edge shows up. The BenchAlign headline says tie; the benchmark table is where the real choice happens.
Gemini 2.5 Pro is also the more expensive model on tokens at $1.25 input / $10.00 output per 1M tokens, versus $0.30 input / $2.50 output per 1M tokens for Gemini 3.5 Flash-Lite. That is roughly 4.0x on output cost alone. Gemini 3.5 Flash-Lite is the reasoning model in the pair, while Gemini 2.5 Pro is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use.
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 2.5 Pro | Δ | Gemini 3.5 Flash-Lite |
|---|---|---|---|
| Coding | Gemini 2.5 Pro63.8 | Margin← 9.6 | Gemini 3.5 Flash-Lite54.2 |
| Agentic | Gemini 2.5 ProNot measured | MarginNo overlap | Gemini 3.5 Flash-Lite63.4 |
| Reasoning | Gemini 2.5 ProNot measured | MarginNo overlap | Gemini 3.5 Flash-Lite72.2 |
| Knowledge | Gemini 2.5 Pro27.4 | MarginNo overlap | Gemini 3.5 Flash-LiteNot measured |
| Math | Gemini 2.5 Pro11.6 | MarginNo overlap | Gemini 3.5 Flash-LiteNot measured |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Gemini 2.5 Pro | Gemini 3.5 Flash-Lite | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Gemini 2.5 Pro$1.25 input / $10 output | Gemini 3.5 Flash-Lite$0.3 input / $2.5 output | Gemini 3.5 Flash-Lite has the lower combined listed price. |
| Generation speedtokens per second | Gemini 2.5 Pro117 tok/s | Gemini 3.5 Flash-LiteNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Gemini 2.5 Pro21.19 s | Gemini 3.5 Flash-LiteNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Gemini 2.5 Pro1M | Gemini 3.5 Flash-Lite1M | Listed context windows are equal. |
Benchmark Deep Dive
Agentic9 benchmarks
| Benchmark | Gemini 2.5 Pro | Gemini 3.5 Flash-Lite | Result |
|---|---|---|---|
| AA Agentic IndexSource | 7.1% | 26.8% | Gemini 3.5 Flash-Lite leads |
| τ²-bench resultsSource | 54.1% | — | Not comparable |
| Gert LabsSource | 42.01% | — | Not comparable |
| GDPval-AASource | 8.3% | 32.0% | Gemini 3.5 Flash-Lite leads |
| GDPval-AASource | 665 | 1140 | Gemini 3.5 Flash-Lite leads |
| Terminal-Bench 2.0Source | — | 54% | Not comparable |
| OSWorld-VerifiedSource | — | 74% | Not comparable |
| AA BriefcaseSource | — | 634 | Not comparable |
| AA Tau3 BankingSource | — | 16.5% | Not comparable |
CodingGemini 2.5 Pro wins6 benchmarks
| Benchmark | Gemini 2.5 Pro | Gemini 3.5 Flash-Lite | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 63.8% | — | Not comparable |
| Vibe Code BenchSource | 0.40% | — | Not comparable |
| AA Coding IndexSource | 33.3% | 49.3% | Gemini 3.5 Flash-Lite leads |
| AA-SciCodeSource | 42.8% | 40.9% | Gemini 2.5 Pro leads |
| Terminal-Bench 2.0Source | — | 54.0% | Not comparable |
| SWE-bench ProSource | — | 54.2% | Not comparable |
Reasoning3 benchmarks
Knowledge8 benchmarks
| Benchmark | Gemini 2.5 Pro | Gemini 3.5 Flash-Lite | Result |
|---|---|---|---|
| GPQASource | 83% | — | Not comparable |
| HLESource | 18.8% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | 25.8% | 36.5% | Gemini 3.5 Flash-Lite leads |
| AA-GPQA DiamondSource | 84.4% | 83.8% | Gemini 2.5 Pro leads |
| AA-HLESource | 21.1% | 17.5% | Gemini 2.5 Pro leads |
| AA-Omniscience IndexSource | -14.3% | 6.9% | Gemini 3.5 Flash-Lite leads |
| AA-Omniscience AccuracySource | 39.0% | 30.3% | Gemini 2.5 Pro leads |
| AA-Omniscience Hallucination RateSource | 87.4% | 33.5% | Gemini 3.5 Flash-Lite leads |
Math2 benchmarks
Multimodal2 benchmarks
Inst. Following1 benchmarks
| Benchmark | Gemini 2.5 Pro | Gemini 3.5 Flash-Lite | Result |
|---|---|---|---|
| AA-IFBenchSource | 48.7% | — | Not comparable |
Frequently Asked Questions (2)
Which is better, Gemini 2.5 Pro or Gemini 3.5 Flash-Lite?
Gemini 2.5 Pro and Gemini 3.5 Flash-Lite are tied on the BenchAlign overall score, so the right pick depends on which category matters most for your use case.
Which is better for coding, Gemini 2.5 Pro or Gemini 3.5 Flash-Lite?
Gemini 2.5 Pro has the edge for coding in this comparison, averaging 63.8 versus 54.2. Inside this category, AA Coding Index is the benchmark that creates the most daylight between them.
Related Comparisons
Explore More
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.