GPT-5.3-Codex

Pricing — 1 offering(s)

Showing the active price and any recorded history. Full pricing history is available via the paid API — see API docs.

Capability profile

Operator guidance

OpenAI's current default/flagship coding model — prefer this over the older gpt-5.2-codex for any new agentic-coding integration, at the same price point. Real, sourced coding-benchmark scores are tracked in modelglass-coding (78.00% SWE-bench Verified via Vals AI, rank #19/72; 56.8% SWE-bench Pro Public at xhigh effort per OpenAI's own launch blog) — consult that vertical directly rather than this doc for benchmark comparisons.

Use cases

• The most capable agentic coding tasks OpenAI currently offers — its own framing: "the most capable agentic coding model to date"
• Long-horizon, tool-heavy coding workflows in Codex or similar agentic environments

Limitations

• Classified 'High' capability for cybersecurity under OpenAI's Preparedness Framework — the first model OpenAI treats as High, and described as the most cyber-capable model it has deployed to date. Source is the GPT-5.3-Codex System Card (openai.com/index/gpt-5-3-codex-system-card/), NOT the API model docs page, which carries no such text (citation corrected 2026-09-03)
• Only the v1/responses endpoint is supported — Chat Completions, Assistants, Batch, and most other OpenAI endpoints are not available for this model
• No standalone general-purpose "GPT-5.3" model exists — this is a coding-specialized model, not a variant of a general-purpose GPT-5.3. (The gpt-5.3-codex API docs page itself is live as of 2026-09-03 — an earlier note that it 404'd is no longer accurate.)
• Capability ratings above are qualitative vendor framing — see modelglass-coding for this model's actual sourced benchmark scores

Citations

• GPT-5.3-Codex model spec (OpenAI's own docs)
• Introducing GPT-5.3-Codex (OpenAI's own launch post)
• GPT-5.3-Codex System Card (Preparedness Framework 'High' cyber classification)
• OpenAI API pricing