Claude Sonnet 4.5 vs Codex Mini
Compare Anthropic and OpenAI AI models
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
Claude Sonnet 4.5
Codex Mini
Cost Differences
Codex Mini costs less than Claude Sonnet 4.5
Feature Comparison
| Feature | Claude Sonnet 4.5 | Codex Mini |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input Price | $3.00/1M tokens | $1.50/1M tokens |
| Output Price | $15.00/1M tokens | $6.00/1M tokens |
| Context Window | 200,000 tokens | 200,000 tokens |
| Max Output | 64,000 tokens | 32,768 tokens |
| Category | balanced | efficient |
| Capabilities | textvisioncode | textcodereasoning |
| Release Date | 9/29/2025 | 2/2/2026 |
Claude Sonnet 4.5 vs Codex Mini: Which Should You Choose?
Choosing between Claude Sonnet 4.5 and Codex Mini depends on your priorities: cost efficiency, context length, or raw capability. Codex Mini is the more affordable option at $1.50/1M input tokens — 50% cheaper than Claude Sonnet 4.5.
These models come from different providers — Anthropic and OpenAI — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with Anthropic, switching to OpenAIinvolves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
These models target different tiers: Claude Sonnet 4.5 is a balanced model while Codex Mini is efficient. This means they're optimized for different workloads. Codex Mini targets more demanding workloads, while Claude Sonnet 4.5 provides a cost-effective option for everyday tasks.
Output costs matter too. Claude Sonnet 4.5 charges $15.00/1M output tokens vs $6.00 for Codex Mini. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Codex Mini has the edge here at $6.00/1M output tokens.
Multimodal capabilities: Claude Sonnet 4.5 supports vision (image inputs) while Codex Mini is text-only. If your application needs image understanding, this narrows your choice.
Best Use Cases
Choose Claude Sonnet 4.5 when:
- • You need longer outputs (up to 64,000 tokens)
- • You're already using Anthropic's API ecosystem
Choose Codex Mini when:
- • Budget is a primary concern
- • You're already using OpenAI's API ecosystem
- • You're running high-volume, latency-sensitive workloads
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
Claude Sonnet 4.5 (Anthropic)
Codex Mini (OpenAI)
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