Codex Mini vs Gemini 3 Flash
Codex Mini vs Gemini 3 Flash: Gemini 3 Flash is cheaper for input-heavy usage ($0.50/M vs $1.50/M input tokens), while Gemini 3 Flash is better for long-context tasks (1,000,000 tokens).
Direct answer: choose Gemini 3 Flash for lower token spend and choose Gemini 3 Flash when your workload needs longer context.
Compare input and output token pricing, context windows, and monthly cost estimates on one page so you can pick the cheaper model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
Codex Mini
Gemini 3 Flash
Cost Differences
Gemini 3 Flash costs less than Codex Mini
Quick Recommendation
Winner for direct API pricing: Gemini 3 Flash. At the default workload, Gemini 3 Flash saves about $7.50/month ($91.25/year) versus Codex Mini.
Feature Comparison
| Feature | Codex Mini | Gemini 3 Flash |
|---|---|---|
| Provider | OpenAI | |
| Input Price | $1.50/1M tokens | $0.50/1M tokens |
| Output Price | $6.00/1M tokens | $3.00/1M tokens |
| Context Window | 200,000 tokens | 1,000,000 tokens |
| Max Output | 32,768 tokens | 65,536 tokens |
| Category | efficient | efficient |
| Capabilities | textcodereasoning | textvisionaudiocode |
| Release Date | 2/2/2026 | 12/17/2025 |
Codex Mini vs Gemini 3 Flash: Which Should You Choose?
Choosing between Codex Mini and Gemini 3 Flash 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 — 67% cheaper than Codex Mini. Meanwhile, Gemini 3 Flash offers a significantly larger context window at 1,000,000 tokens vs 200,000 for Codex Mini.
These models come from different providers — OpenAI and Google — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with OpenAI, switching to Googleinvolves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
Both models are in the efficient category, making this a direct head-to-head comparison. At scale — say 10,000 requests per day — the cost difference adds up: Gemini 3 Flash would save you roughly $750.00/month compared to Codex Mini. For startups and indie developers, that difference can be significant.
Output costs matter too. Codex Mini charges $6.00/1M output tokens vs $3.00 for Gemini 3 Flash. 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 Codex Mini is text-only. If your application needs image understanding, this narrows your choice.
Best Use Cases
Choose Codex Mini when:
- • You're already using OpenAI's API ecosystem
- • You're running high-volume, latency-sensitive workloads
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
Pros and Caveats at a Glance
Codex Mini
- • Input pricing: $1.50/M tokens
- • Output pricing: $6.00/M tokens
- • Context window: 200,000 tokens
- • Max output: 32,768 tokens
Watch out for
- • Higher input cost than Gemini 3 Flash
- • Higher output cost than Gemini 3 Flash
- • Smaller context window than Gemini 3 Flash
Gemini 3 Flash
- • Input pricing: $0.50/M tokens
- • Output pricing: $3.00/M tokens
- • Context window: 1,000,000 tokens
- • Max output: 65,536 tokens
Watch out for
- • Trade-offs are minor in this matchup.
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
Codex Mini (OpenAI)
Gemini 3 Flash (Google)
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Which is cheaper, Codex Mini or Gemini 3 Flash?▼
What is the context window difference between Codex Mini and Gemini 3 Flash?▼
Which model is better for AI Chatbot?▼
Which model has better overall pricing for heavy usage?▼
Where can I compare OpenAI and Google API pricing beyond this model matchup?▼
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