Model comparison
Gemini 3.5 Flash-Lite vs GPT-5.5 Pro
Head-to-head evidence from 1 shared benchmark result across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Gemini 3.5 Flash-Lite unranked (Not scored); GPT-5.5 Pro #38 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Gemini 3.5 Flash-Lite and GPT-5.5 Pro share 1 comparable benchmark result. 1 of 8 categories are comparable. 20 results are unique to Gemini 3.5 Flash-Lite; 6 to GPT-5.5 Pro.
Updated July 21, 2026- Shared results
- 1
- Gemini 3.5 Flash-Lite only
- 20
- GPT-5.5 Pro only
- 6
- Comparable categories
- 1 / 8
Treat this as a split decision. Gemini 3.5 Flash-Lite makes more sense if you want the cheaper token bill; GPT-5.5 Pro is the better fit if agentic is the priority.
Confidence note. This is a partial-evidence comparison with 1 shared benchmark result across 1 evidence category; 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 3.5 Flash-Lite and GPT-5.5 Pro 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.
GPT-5.5 Pro is also the more expensive model on tokens at $30.00 input / $180.00 output per 1M tokens, versus $0.30 input / $2.50 output per 1M tokens for Gemini 3.5 Flash-Lite. That is roughly 72.0x on output cost alone.
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 3.5 Flash-Lite | Δ | GPT-5.5 Pro |
|---|---|---|---|
| Agentic | Gemini 3.5 Flash-Lite63.4 | Margin→ 26.7 | GPT-5.5 Pro90.1 |
| Coding | Gemini 3.5 Flash-Lite54.2 | MarginNo overlap | GPT-5.5 ProNot measured |
| Reasoning | Gemini 3.5 Flash-Lite72.2 | MarginNo overlap | GPT-5.5 ProNot measured |
| Knowledge | Gemini 3.5 Flash-LiteNot measured | MarginNo overlap | GPT-5.5 Pro57.2 |
| Math | Gemini 3.5 Flash-LiteNot measured | MarginNo overlap | GPT-5.5 Pro48.1 |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Gemini 3.5 Flash-Lite | GPT-5.5 Pro | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Gemini 3.5 Flash-Lite$0.3 input / $2.5 output | GPT-5.5 Pro$30 input / $180 output | Gemini 3.5 Flash-Lite has the lower combined listed price. |
| Generation speedtokens per second | Gemini 3.5 Flash-LiteNot available | GPT-5.5 ProNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Gemini 3.5 Flash-LiteNot available | GPT-5.5 ProNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Gemini 3.5 Flash-Lite1M | GPT-5.5 Pro1M | Listed context windows are equal. |
Benchmark Deep Dive
AgenticGPT-5.5 Pro wins8 benchmarks
| Benchmark | Gemini 3.5 Flash-Lite | GPT-5.5 Pro | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 54% | — | Not comparable |
| OSWorld-VerifiedSource | 74% | — | Not comparable |
| GDPval-AASource | 1140 | — | Not comparable |
| AA Agentic IndexSource | 26.8% | — | Not comparable |
| GDPval-AASource | 32.0% | — | Not comparable |
| AA BriefcaseSource | 634 | — | Not comparable |
| AA Tau3 BankingSource | 16.5% | — | Not comparable |
| BrowseCompSource | — | 90.1% | Not comparable |
Coding4 benchmarks
Reasoning3 benchmarks
Knowledge8 benchmarks
| Benchmark | Gemini 3.5 Flash-Lite | GPT-5.5 Pro | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 36.5% | — | Not comparable |
| AA-GPQA DiamondSource | 83.8% | — | Not comparable |
| AA-HLESource | 17.5% | — | Not comparable |
| AA-Omniscience IndexSource | 6.9% | — | Not comparable |
| AA-Omniscience AccuracySource | 30.3% | — | Not comparable |
| AA-Omniscience Hallucination RateSource | 33.5% | — | Not comparable |
| HLESource | — | 57.2% | Not comparable |
| HLE w/o toolsSource | — | 43.1% | Not comparable |
Math3 benchmarks
Multimodal1 benchmarks
| Benchmark | Gemini 3.5 Flash-Lite | GPT-5.5 Pro | Result |
|---|---|---|---|
| AA-MMMU-ProSource | 79.0% | — | Not comparable |
Frequently Asked Questions (2)
Which is better, Gemini 3.5 Flash-Lite or GPT-5.5 Pro?
Gemini 3.5 Flash-Lite and GPT-5.5 Pro 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 agentic tasks, Gemini 3.5 Flash-Lite or GPT-5.5 Pro?
GPT-5.5 Pro has the edge for agentic tasks in this comparison, averaging 90.1 versus 63.4. Gemini 3.5 Flash-Lite stays close enough that the answer can still flip depending on your workload.
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