Claude Opus 4.5 vs GPT-5.2 Codex
Claude Opus 4.5 (2025) and GPT-5.2 Codex (2025) compare a standalone API model against a coding-specialized model. Claude Opus 4.5 ships a 200k-token context window, while GPT-5.2 Codex ships a 400k-token context window. On SWE-bench Verified, Claude Opus 4.5 leads by 8.1 pts. On pricing, GPT-5.2 Codex costs $1.75/1M input tokens versus $5/1M 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: Claude Opus 4.5 is standalone API model, while GPT-5.2 Codex is coding-specialized model. Choose based on workflow fit before reading any benchmark or price row as decisive.
Decision scorecard
Local evidence first| Signal | Claude Opus 4.5 | GPT-5.2 Codex |
|---|---|---|
| Product type | Standalone API model | Coding-specialized model |
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | custom coding agents, code generation, and tool loops |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 200k | 400k |
| Cheapest output | $25/1M tokens | $14/1M tokens |
| Provider routes | 6 tracked | 2 tracked |
| Shared benchmarks | SWE-bench Verified leader | 2 shared |
Decision tradeoffs
- Claude Opus 4.5 holds a shared-benchmark lead on SWE-bench Verified, ahead by 8.1 points.
- Claude Opus 4.5 has broader tracked provider coverage for fallback and route flexibility.
- Local decision data tags Claude Opus 4.5 for Coding, RAG, and Agents.
- GPT-5.2 Codex holds a shared-benchmark lead on SWE-bench Pro, ahead by 14.6 points.
- 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.
- Local decision data tags GPT-5.2 Codex for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Claude Opus 4.5
$10,250
Cheapest tracked route/tier: Microsoft Foundry
GPT-5.2 Codex
$4,900
Cheapest tracked route/tier: Vercel AI Gateway
Estimated monthly gap: $5,350. 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.
- GPT-5.2 Codex is $11/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
- Claude Opus 4.5 is $11/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-11-01 | 2025-12-18 |
| Context window | 200k | 400k |
| 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 | 2025-12 | 2025-08 |
Pricing and availability
| Pricing attribute | Claude Opus 4.5 | GPT-5.2 Codex |
|---|---|---|
| Input price | $5/1M tokens | $1.75/1M tokens |
| Output price | $25/1M tokens | $14/1M tokens |
| Providers |
Capabilities
| Capability | Claude Opus 4.5 | GPT-5.2 Codex |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| JSON / Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Claude Opus 4.5 | GPT-5.2 Codex |
|---|---|---|
| SWE-bench Verified | 80.9 | 72.8 |
| SWE-bench Pro | 41.8 | 56.4 |
Continue comparing
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Last reviewed: 2026-07-26. Data sourced from public model cards and provider documentation.