GPT-5.3-Codex vs Grok 3 Mini
GPT-5.3-Codex (2026) and Grok 3 Mini (2025) compare a coding-specialized model against a standalone API model. GPT-5.3-Codex ships a 400k-token context window, while Grok 3 Mini ships a 131k-token context window. On pricing, Grok 3 Mini costs $0.25/1M input tokens versus $1.75/1M 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-5.3-Codex is coding-specialized model, while Grok 3 Mini 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-5.3-Codex | Grok 3 Mini |
|---|---|---|
| Product type | Coding-specialized model | Standalone API model |
| Best for | custom coding agents, code generation, and tool loops | multimodal apps and provider-routed production |
| Decision fit | Coding, RAG, and Agents | RAG, Long context, and Vision |
| Context window | 400k | 131k |
| Cheapest output | $14/1M tokens | $1.27/1M tokens |
| Provider routes | 3 tracked | 2 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- GPT-5.3-Codex has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GPT-5.3-Codex has broader tracked provider coverage for fallback and route flexibility.
- GPT-5.3-Codex uniquely exposes Reasoning, JSON / Tool use, and Code execution in local model data.
- Local decision data tags GPT-5.3-Codex for Coding, RAG, and Agents.
- Grok 3 Mini has the lower cheapest tracked output price at $1.27/1M tokens.
- Grok 3 Mini uniquely exposes Multimodal in local model data.
- Local decision data tags Grok 3 Mini for RAG, Long context, and Vision.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
GPT-5.3-Codex
$4,900
Cheapest tracked route/tier: OpenRouter
Grok 3 Mini
$518
Cheapest tracked route/tier: Microsoft Foundry
Estimated monthly gap: $4,383. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Grok 3 Mini is $12.73/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Reasoning, JSON / Tool use, and Code execution before moving production traffic.
- Grok 3 Mini adds Multimodal in local capability data.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- GPT-5.3-Codex is $12.73/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Multimodal before moving production traffic.
- GPT-5.3-Codex adds Reasoning, JSON / Tool use, and Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-02-05 | 2025-02-17 |
| Context window | 400k | 131k |
| Parameters | — | — |
| Architecture | 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 | 2024-11 |
Pricing and availability
| Pricing attribute | GPT-5.3-Codex | Grok 3 Mini |
|---|---|---|
| Input price | $1.75/1M tokens | $0.25/1M tokens |
| Output price | $14/1M tokens | $1.27/1M tokens |
| Providers |
Capabilities
| Capability | GPT-5.3-Codex | Grok 3 Mini |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | No | Yes |
| Reasoning | Yes | No |
| JSON / Tool use | Yes | No |
| Structured outputs | Yes | Yes |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | Yes | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
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Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.