Gemini 3.5 Flash vs o3-pro
At a Glance
| Compare |  Gemini 3.5 FlashGoogle DeepMind |  o3-proOpenAI |
|---|---|---|
| Intelligence, Cost, and Efficiency | ||
| IntelligenceHigher is better · MM Intelligence v2.5 | #15 of 4672.1 score · 3/3 sources · complete | UnrankedNot in the 46-model eligible cohort |
| CostLower is better · Published-token output estimate | #25 of 44$0.140 per LiveBench case | UnrankedNot in the 44-model eligible cohort |
| EfficiencyHigher is better · MM Efficiency v1.5 | #15 of 3856.8 score · 3/3 sources · complete | UnrankedNot in the 38-model eligible cohort |
| Pricing and Limits | ||
| Input priceFrom · USD / 1M tokens | $1.50Google AI ↗ · Aug 29, 2026 | $20.00Openai ↗ · Sep 3, 2026 |
| Output priceFrom · USD / 1M tokens | $9.00Google AI ↗ · Aug 29, 2026 | $80.00Openai ↗ · Sep 3, 2026 |
| Context windowMaximum documented tokens | 1,049K | 200K |
| Model facts checked | Aug 29, 2026View model evidence → | Sep 3, 2026View model evidence → |
Token prices are the lowest available sourced USD rates; input and output may use different providers. Cost ranking estimates output spend on LiveBench, not a full request bill. Ranking methodology →
Available Benchmarks
Side-by-Side Facts
| Field | Gemini 3.5 Flash | o3-pro |
|---|---|---|
| Developer | Google DeepMind | OpenAI |
| Family | Gemini 3 | O3 |
| Model | Gemini 3.5 Flash | o3-pro |
| Version | Gemini 3.5 Flash | o3-pro |
| Lifecycle | active | active |
| Released | Unknown | 2025-06-10 |
| Knowledge cutoff | Unknown | 2024-06-01 |
| Input modalities | Text, Image, Video, Audio, Document | Text, Image |
| Output modalities | Text | Text |
| Context window | 1,049K | 200K |
| Total parameters | Unknown | Unknown |
| Active parameters | Unknown | Unknown |
| License | Unknown | Unknown |
| Open weights | No | No |
| API available | Yes | Yes |
| Self-hostable | No | No |
| Provider access | Google AI (Standard), Google Gemini (Standard) | Openai (Standard), Openrouter (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, generation, reasoning, structured_outputs, tools |
Gemini 3.5 Flash Capabilities
o3-pro Capabilities
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Primary Evidence
Sources and Freshness
Questions
Gemini 3.5 Flash vs o3-pro FAQs
Is Gemini 3.5 Flash or o3-pro better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Gemini 3.5 Flash and o3-pro, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Gemini 3.5 Flash or o3-pro?+
Gemini 3.5 Flash is $1.50 and o3-pro is $20.00 per million tokens, so Gemini 3.5 Flash is cheaper on this metric. Gemini 3.5 Flash is $9.00 and o3-pro is $80.00 per million tokens, so Gemini 3.5 Flash is cheaper on this metric.
Which has a larger context window, Gemini 3.5 Flash or o3-pro?+
Gemini 3.5 Flash has the larger sourced context window. Gemini 3.5 Flash supports 1,049K and o3-pro supports 200K.
Which performs better in benchmarks, Gemini 3.5 Flash or o3-pro?+
There is no overall benchmark winner: At least two independently verified, protocol-matched benchmarks are required for an overall winner.
Can Gemini 3.5 Flash or o3-pro be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Gemini 3.5 Flash is not marked open weight; o3-pro is not marked open weight.
Can Gemini 3.5 Flash and o3-pro understand images?+
Gemini 3.5 Flash is documented with image input; o3-pro is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Gemini 3.5 Flash or o3-pro?+
o3-pro has the larger sourced maximum output: Gemini 3.5 Flash supports 66K and o3-pro supports 100K output tokens.
Do Gemini 3.5 Flash and o3-pro support reasoning and tool use?+
Gemini 3.5 Flash: reasoning, tool calling, and image input. o3-pro: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Gemini 3.5 Flash or o3-pro?+
Gemini 3.5 Flash has 2 sourced provider routes; o3-pro has 2, a tie.
Which offers better value, Gemini 3.5 Flash or o3-pro?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.