AIpedia#99 GPT-5.3-Codex
Released: · SourceGPT-5.3-Codex is a model from OpenAI. Exact version: gpt-5.3-codex. See the source for capabilities and limitations.
- Use cases
- Coding, Image understanding, Reasoning, Text
- Accepts
- Text & code, Images
- Produces
- Text & code
- Context
- 400000 tokens
Access
Price USD
No verified data
Evaluator & score
Composite index · published model-group index · 20.09.2026 · Higher is better
Snapshot: 2026-09-20 · 90% CI [153.91, 159.73]
Official Epoch AI index; combines own, third-party and developer-reported results. It is not a safety audit or a media-generation score.
Conditions
Epoch Capabilities Index; official model-group estimates
Official ECI model scores, Epoch AI, CC BY 4.0. Composite of own, third-party and developer-reported results. 90% bootstrap interval. Not a per-effort score; export date is the model release date, not measurement date. Methodology: https://epoch.ai/eci#documentation
Independent run · high · 20.09.2026 · Higher is better
Snapshot: 2026-09-20
Conditions
SWE-bench Verified; Epoch AI own run; best score across scorers
Epoch AI own run; SWE-Bench verified; version: gpt-5.3-codex_high; mode: high; source id: 6w5buMbgeEqtRoE55cLZVv; file: swe_bench_verified.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.
Measurement date: 25.02.2026