Model comparison
GPT-5.3 Codex vs Llama 13b
GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 24.4 on the Noometry Index.
Last verified . 1 shared benchmarks.
MetaSummary
- They share 1 benchmark with published results for both. GPT-5.3 Codex scores higher in 1 category and Llama 13b in 0 categories; one gap is clear of the uncertainty.
- The widest gap is in coding, where GPT-5.3 Codex leads 48.6 to 21.4.
- Llama 13b has downloadable open weights; the other is API-only.
Side by side
| GPT-5.3 Codex | Llama 13b | |
|---|---|---|
| Provider | OpenAI | Meta |
| Noometry Index | 45.8 | 24.4 |
| Released | 2026-02-05 | 2023-02-24 |
| Weights | Proprietary | Open |
| Context window | 400K | — |
| Max output | 128K | — |
| Input $ / M tokens | $1.75 | — |
| Output $ / M tokens | $14 | — |
| Results tracked | 8 | 21 |
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Category by category
Coding GPT-5.3 Codex leads
GPT-5.3 Codex: 48.6 (#56), Llama 13b: 21.4 (#337)
| Benchmark | GPT-5.3 Codex | Llama 13b |
|---|---|---|
| SWE-bench Verified | 74.8% | — |
| LMArena WebDev | 1409 | — |
| WeirdML | 79.3% | — |
| LMArena Coding | — | 683 |
| ALE-Bench | 1,655 | — |
Agentic & Tool Use Not comparable
GPT-5.3 Codex: 48.0 (#9), Llama 13b: —
| Benchmark | GPT-5.3 Codex | Llama 13b |
|---|---|---|
| Terminal-Bench | 78.4% | — |
| METR Time Horizons | 74.5% | — |
| Vending-Bench 2 | 5,940 | — |
Reasoning Not comparable
GPT-5.3 Codex: —, Llama 13b: 14.0 (#329)
| Benchmark | GPT-5.3 Codex | Llama 13b |
|---|---|---|
| Epoch Capabilities Index | 156.77 | 100.58 |
| LMArena Hard Prompts | — | 728 |
| BIG-Bench Hard | — | 37.9% |
| HellaSwag | — | 79.2% |
| LAMBADA | — | 75.2% |
| PIQA | — | 80.1% |
| WinoGrande | — | 73% |
Math Not comparable
GPT-5.3 Codex: —, Llama 13b: 26.7 (#256)
| Benchmark | GPT-5.3 Codex | Llama 13b |
|---|---|---|
| LMArena Math | — | 838 |
| GSM8K | — | 20.6% |
Knowledge Not comparable
GPT-5.3 Codex: —, Llama 13b: —
| Benchmark | GPT-5.3 Codex | Llama 13b |
|---|---|---|
| ARC (AI2) Challenge | — | 52.7% |
| BoolQ | — | 78.7% |
| MMLU | — | 47.7% |
| OpenBookQA | — | 56.4% |
| TriviaQA | — | 77.9% |
Multimodal Not comparable
GPT-5.3 Codex: —, Llama 13b: —
| Benchmark | GPT-5.3 Codex | Llama 13b |
|---|---|---|
| ScienceQA | — | 43.3% |
Multilingual Not comparable
GPT-5.3 Codex: —, Llama 13b: 16.6 (#297)
| Benchmark | GPT-5.3 Codex | Llama 13b |
|---|---|---|
| LMArena Non-English | — | 819 |
Instruction Following Not comparable
GPT-5.3 Codex: —, Llama 13b: 36.7 (#305)
| Benchmark | GPT-5.3 Codex | Llama 13b |
|---|---|---|
| LMArena Instruction Following | — | 781 |
Writing & Preference Not comparable
GPT-5.3 Codex: —, Llama 13b: 13.8 (#312)
| Benchmark | GPT-5.3 Codex | Llama 13b |
|---|---|---|
| LMArena Text | — | 834 |
| LMArena Creative Writing | — | 794 |
| LMArena Multi-Turn | — | 753 |
Frequently asked questions
Is GPT-5.3 Codex better than Llama 13b?
GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 24.4 on the Noometry Index.
Is GPT-5.3 Codex or Llama 13b better for coding?
GPT-5.3 Codex scores higher on coding benchmarks: 48.6 versus 21.4 in the Noometry coding category.
How many benchmarks do GPT-5.3 Codex and Llama 13b share?
1 benchmark has published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and Llama 13b has 21.