Gemini 3 Flash vs GPT-5.3 Codex
Compare Google and OpenAI AI models
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
Gemini 3 Flash
GPT-5.3 Codex
Cost Differences
GPT-5.3 Codex costs more than Gemini 3 Flash
Feature Comparison
| Feature | Gemini 3 Flash | GPT-5.3 Codex |
|---|---|---|
| Provider | OpenAI | |
| Input Price | $0.50/1M tokens | $1.75/1M tokens |
| Output Price | $3.00/1M tokens | $14.00/1M tokens |
| Context Window | 1,000,000 tokens | 256,000 tokens |
| Max Output | 65,536 tokens | 32,768 tokens |
| Category | efficient | coding |
| Capabilities | textvisionaudiocode | textcode |
| Release Date | 12/17/2025 | 3/1/2026 |
Gemini 3 Flash vs GPT-5.3 Codex: Which Should You Choose?
Choosing between Gemini 3 Flash and GPT-5.3 Codex depends on your priorities: cost efficiency, context length, or raw capability. Gemini 3 Flash is the more affordable option at $0.50/1M input tokens — 71% cheaper than GPT-5.3 Codex. Meanwhile, Gemini 3 Flash offers a significantly larger context window at 1,000,000 tokens vs 256,000 for GPT-5.3 Codex.
These models come from different providers — Google and OpenAI — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with Google, switching to OpenAIinvolves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
These models target different tiers: Gemini 3 Flash is a efficient model while GPT-5.3 Codex is coding. This means they're optimized for different workloads. GPT-5.3 Codex targets more demanding workloads, while Gemini 3 Flash provides a cost-effective option for everyday tasks.
Output costs matter too. Gemini 3 Flash charges $3.00/1M output tokens vs $14.00 for GPT-5.3 Codex. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Gemini 3 Flash has the edge here at $3.00/1M output tokens.
Multimodal capabilities: Gemini 3 Flash supports vision (image inputs) while GPT-5.3 Codex is text-only. If your application needs image understanding, this narrows your choice.
Best Use Cases
Choose Gemini 3 Flash when:
- • Budget is a primary concern
- • You need a larger context window (1,000,000 tokens)
- • You need more capabilities (vision, audio)
- • You need longer outputs (up to 65,536 tokens)
- • You're already using Google's API ecosystem
- • You're running high-volume, latency-sensitive workloads
Choose GPT-5.3 Codex when:
- • You're already using OpenAI's API ecosystem
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
Gemini 3 Flash (Google)
GPT-5.3 Codex (OpenAI)
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