GPT-5.2 Codex vs o3 Deep Research
GPT-5.2 Codex (2025) and o3 Deep Research (2025) compare a coding-specialized model against a standalone API model. GPT-5.2 Codex ships a 400k-token context window, while o3 Deep Research ships a 200k-token context window. On pricing, GPT-5.2 Codex costs $1.75/1M input tokens versus $10/1M for the alternative. This page treats the result as workflow and deployment fit, not a universal model winner.
Treat this as a product-type comparison: GPT-5.2 Codex is coding-specialized model, while o3 Deep Research is standalone API model. Choose based on workflow fit before reading any benchmark or price row as decisive.
Decision scorecard
Local evidence first| Signal | GPT-5.2 Codex | o3 Deep Research |
|---|---|---|
| Product type | Coding-specialized model | Standalone API model |
| Best for | custom coding agents, code generation, and tool loops | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | RAG, Agents, and Long context |
| Context window | 400k | 200k |
| Cheapest output | $14/1M tokens | $40/1M tokens |
| Provider routes | 2 tracked | 1 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- GPT-5.2 Codex has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GPT-5.2 Codex has the lower cheapest tracked output price at $14/1M tokens.
- GPT-5.2 Codex has broader tracked provider coverage for fallback and route flexibility.
- GPT-5.2 Codex uniquely exposes Code execution in local model data.
- Local decision data tags GPT-5.2 Codex for Coding, RAG, and Agents.
- Local decision data tags o3 Deep Research for RAG, Agents, and Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
GPT-5.2 Codex
$4,900
Cheapest tracked route/tier: Vercel AI Gateway
o3 Deep Research
$18,000
Cheapest tracked route/tier: Vercel AI Gateway
Estimated monthly gap: $13,100. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
- o3 Deep Research is $26/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Code execution before moving production traffic.
- Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
- GPT-5.2 Codex is $26/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- GPT-5.2 Codex adds Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-12-18 | 2025-10-10 |
| Context window | 400k | 200k |
| Parameters | — | — |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Weights | Not released | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | 2025-08 | 2024-06 |
Pricing and availability
| Pricing attribute | GPT-5.2 Codex | o3 Deep Research |
|---|---|---|
| Input price | $1.75/1M tokens | $10/1M tokens |
| Output price | $14/1M tokens | $40/1M tokens |
| Providers |
Capabilities
| Capability | GPT-5.2 Codex | o3 Deep Research |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| JSON / Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
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Last reviewed: 2026-06-30. Data sourced from public model cards and provider documentation.