GPT-5.3 Codex vs o3 Deep Research
Compare OpenAI and OpenAI AI models
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
GPT-5.3 Codex
o3 Deep Research
Cost Differences
o3 Deep Research costs more than GPT-5.3 Codex
Feature Comparison
| Feature | GPT-5.3 Codex | o3 Deep Research |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Input Price | $1.75/1M tokens | $10.00/1M tokens |
| Output Price | $14.00/1M tokens | $40.00/1M tokens |
| Context Window | 256,000 tokens | 200,000 tokens |
| Max Output | 32,768 tokens | 32,768 tokens |
| Category | coding | reasoning |
| Capabilities | textcode | textreasoningvisioncode |
| Release Date | 3/1/2026 | 6/26/2025 |
GPT-5.3 Codex vs o3 Deep Research: Which Should You Choose?
Choosing between GPT-5.3 Codex and o3 Deep Research depends on your priorities: cost efficiency, context length, or raw capability. GPT-5.3 Codex is the more affordable option at $1.75/1M input tokens — 83% cheaper than o3 Deep Research. Meanwhile, GPT-5.3 Codex offers a significantly larger context window at 256,000 tokens vs 200,000 for o3 Deep Research.
These models target different tiers: GPT-5.3 Codex is a coding model while o3 Deep Research is reasoning. This means they're optimized for different workloads. o3 Deep Research targets more demanding workloads, while GPT-5.3 Codex provides a cost-effective option for everyday tasks.
Output costs matter too. GPT-5.3 Codex charges $14.00/1M output tokens vs $40.00 for o3 Deep Research. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. GPT-5.3 Codex has the edge here at $14.00/1M output tokens.
Multimodal capabilities: o3 Deep Research 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 GPT-5.3 Codex when:
- • Budget is a primary concern
- • You need a larger context window (256,000 tokens)
- • You're already using OpenAI's API ecosystem
Choose o3 Deep Research when:
- • You need more capabilities (reasoning, vision)
- • You're already using OpenAI's API ecosystem
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
GPT-5.3 Codex (OpenAI)
o3 Deep Research (OpenAI)
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