Mistral: Mistral Small 4 vs OpenAI: GPT-5.3-Codex
Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-11-07.
| Mistral: Mistral Small 4 | OpenAI: GPT-5.3-Codex | |
|---|---|---|
| Vendor | mistralai | openai |
| Quality Score | 100 | 100 |
| Benchmark Score | 6.1 | 73.4 |
| Input Price | $0.15/M | $1.75/M |
| Output Price | $0.60/M | $14.00/M |
| Context Window | 262,144 | 400,000 |
| Max Output | 209,715 | 128,000 |
| Tool Calling | ✓ | ✓ |
| Structured Output | ✓ | ✓ |
| Reasoning Mode | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio | - | - |
| Benchmark Scores | ||
| ai_index | 7.7 | 73.0 |
The verdict
For a sample job of 1 million input tokens and 250,000 output tokens, Mistral Small 4 costs $0.30 and GPT-5.3-Codex costs $5.25, so Mistral Small 4 is about 17.5 times cheaper for the same work.
GPT-5.3-Codex reads up to 400,000 tokens at once, roughly 600 pages of text, against about 393 pages for Mistral Small 4.
On our blended benchmark score GPT-5.3-Codex leads 73.4 to 6.1.
Across the 20 tasks where they differ, Mistral Small 4 scores higher on 4 (Code Completion, JSON Extraction, Bulk Data Labeling and others), GPT-5.3-Codex on 16 (SQL Generation, Code Review, Code Refactoring and others).
Mistral Small 4 was released in March 2026 and GPT-5.3-Codex in February 2026.
Pick Mistral Small 4 if you need lower cost; pick GPT-5.3-Codex if you need long documents, benchmark performance or the stronger all-round task scores.
Costs use current list prices per million tokens; page counts assume about 0.75 words per token and 500 words per page.
Who wins by task?
| Task | Mistral: Mistral Small 4 | OpenAI: GPT-5.3-Codex |
|---|---|---|
| SQL Generation | 132 | 141 |
| Code Review | 127 | 145 |
| Code Completion | 129 | 118 |
| Code Refactoring | 129 | 147 |
| Bug Fixing | 131 | 149 |
| Unit Test Generation | 122 | 132 |
| Code Documentation | 127 | 135 |
| Regex Writing | 120 | 124 |
| CI/CD Pipelines | 118 | 128 |
| Frontend Component Design | 122 | 130 |
| Data Analysis | 125 | 134 |
| CSV / Spreadsheet Cleanup | 128 | 135 |
| ETL Scripting | 123 | 138 |
| JSON Extraction | 131 | 120 |
| Bulk Data Labeling | 129 | 117 |
| OCR / Document Parsing | 128 | 134 |
| Table Extraction from PDFs | 128 | 134 |
| Long-Document Summarization | 130 | 148 |
| Short-Form Summarization | 124 | 116 |
| Blog Post Writing | 120 | 129 |
Scores reflect capability match + benchmark data + pricing for each task. Methodology →