Codex 1 vs Mistral Small 4
Codex 1 (2025) and Mistral Small 4 (2026) compare a coding-specialized model against a standalone API model. Codex 1 ships a 192k-token context window, while Mistral Small 4 ships a 256k-token context window. This page treats the result as workflow and deployment fit, not a universal model winner.
Treat this as a product-type comparison: Codex 1 is coding-specialized model, while Mistral Small 4 is standalone API model. Choose based on workflow fit before reading any benchmark or price row as decisive.
Decision scorecard
Local evidence first| Signal | Codex 1 | Mistral Small 4 |
|---|---|---|
| Product type | Coding-specialized model | Standalone API model |
| Best for | custom coding agents and code generation | multimodal apps, tool-calling agents, and provider-routed production |
| Decision fit | Coding, Agents, and Long context | RAG, Agents, and Long context |
| Context window | 192k | 256k |
| Cheapest output | - | $0.60/1M tokens |
| Provider routes | 0 tracked | 3 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- Codex 1 uniquely exposes Reasoning and Code execution in local model data.
- Local decision data tags Codex 1 for Coding, Agents, and Long context.
- Mistral Small 4 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Mistral Small 4 has broader tracked provider coverage for fallback and procurement flexibility.
- Mistral Small 4 uniquely exposes Vision, Multimodal, and Function calling in local model data.
- Local decision data tags Mistral Small 4 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.
Codex 1
Unavailable
No complete token price in local provider data
Mistral Small 4
$270
Cheapest tracked route/tier: OpenRouter
Cost delta unavailable until both models have sourced input and output token prices.
Switch friction
- No overlapping tracked provider route is sourced for Codex 1 and Mistral Small 4; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Reasoning and Code execution before moving production traffic.
- Mistral Small 4 adds Vision, Multimodal, and Function calling in local capability data.
- No overlapping tracked provider route is sourced for Mistral Small 4 and Codex 1; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Vision, Multimodal, and Function calling before moving production traffic.
- Codex 1 adds Reasoning and Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-05-16 | 2026-03-16 |
| Context window | 192k | 256k |
| Parameters | — | 119B (6.5B active) |
| Architecture | decoder only | moe |
| License | Proprietary | Apache 2.0(OSI) |
| Openness | Proprietary | Open source |
| Commercial use | Commercial use with conditions | Commercial use allowed |
| Knowledge cutoff | - | 2025-06 |
Pricing and availability
| Pricing attribute | Codex 1 | Mistral Small 4 |
|---|---|---|
| Input price | - | $0.15/1M tokens |
| Output price | - | $0.60/1M tokens |
| Providers | - |
Capabilities
| Capability | Codex 1 | Mistral Small 4 |
|---|---|---|
| Vision | No | Yes |
| Multimodal | No | Yes |
| Reasoning | Yes | No |
| Function calling | No | Yes |
| Tool use | No | Yes |
| Structured outputs | No | No |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on vision: Mistral Small 4, multimodal input: Mistral Small 4, reasoning mode: Codex 1, function calling: Mistral Small 4, tool use: Mistral Small 4, and code execution: Codex 1. Both models share the core language-model surface, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
Pricing coverage is uneven: Codex 1 has no token price sourced yet and Mistral Small 4 has $0.15/1M input tokens. Provider availability is 0 tracked routes versus 3. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose Codex 1 when coding workflow support are central to the workload. Choose Mistral Small 4 when long-context analysis, larger context windows, and broader provider choice are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency.
FAQ
Which has a larger context window, Codex 1 or Mistral Small 4?
Mistral Small 4 supports 256k tokens, while Codex 1 supports 192k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Is Codex 1 or Mistral Small 4 open source?
Codex 1 is listed under Proprietary. Mistral Small 4 is listed under Apache 2.0. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, Codex 1 or Mistral Small 4?
Mistral Small 4 has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for multimodal input, Codex 1 or Mistral Small 4?
Mistral Small 4 has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for reasoning mode, Codex 1 or Mistral Small 4?
Codex 1 has the clearer documented reasoning mode signal in this comparison. If reasoning mode is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run Codex 1 and Mistral Small 4?
Codex 1 is available on the tracked providers still being sourced. Mistral Small 4 is available on OpenRouter, NVIDIA NIM, and Mistral AI Studio. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-05-14. Data sourced from public model cards and provider documentation.