What is GPT-5.3-Codex?

GPT-5.3-Codex is a large language model from OpenAI, released on February 5, 2026. It accepts text and image input.

When was GPT-5.3-Codex released?

OpenAI released GPT-5.3-Codex on February 5, 2026.

How much does GPT-5.3-Codex cost?

GPT-5.3-Codex costs $1.75 per 1M input tokens and $14 per 1M output tokens through the OpenAI API. Cached input costs $0.175 per 1M tokens. Prices are from OpenAI's official pricing as of October 5, 2026.

What is GPT-5.3-Codex's context window?

GPT-5.3-Codex has a 400K-token context window and can generate up to 128K output tokens.

How does GPT-5.3-Codex score on benchmarks?

GPT-5.3-Codex has 9 cited benchmark scores, including SWE-bench Verified (Epoch AI run) 74.8%, Vending-Bench 2 (Andon Labs) 5940.12 and WeirdML (Håvard Tveit Ihle) 79.3%. Each score links to its source.

GPT-5.3-Codex

OpenAI·Degraded·Released 2026-02-05textvision

Context400k

Max output128k

Input / 1M$1.75 ↗

Output / 1M$14 ↗

Cached in$0.175

Benchmarks9

Benchmarks

Cited public sources · rank is exact-benchmark, apples-to-apples

SWE-bench Verified (Epoch AI run)

#14/3174.8% ↗

Vending-Bench 2 (Andon Labs)

#20/595940.12 ↗

WeirdML (Håvard Tveit Ihle)

#10/9279.3% ↗

Cybersecurity Capture The Flag Challenges

#1/277.6% ↗

GDPval (wins or ties)

#6/770.9% ↗

OSWorld-Verified

#15/2064.7% ↗

SWE-Bench Pro (Public)

#2/356.8% ↗

SWE-Lancer IC Diamond

#1/281.4% ↗

Terminal-Bench 2.0

#2/2077.3% ↗

Compare

vs Gemini 4 Argon vs GPT-6.1 Sol vs Claude Sonnet 5.5 vs Muse Spark 1.3 vs GPT-6 Sol vs GPT-6 Luna vs Claude Opus 5.5 vs GPT-6 Astra

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GPT-5.3-Codex FAQ

What is GPT-5.3-Codex?: GPT-5.3-Codex is a large language model from OpenAI, released on February 5, 2026. It accepts text and image input.
When was GPT-5.3-Codex released?: OpenAI released GPT-5.3-Codex on February 5, 2026.
How much does GPT-5.3-Codex cost?: GPT-5.3-Codex costs $1.75 per 1M input tokens and $14 per 1M output tokens through the OpenAI API. Cached input costs $0.175 per 1M tokens. Prices are from OpenAI's official pricing as of October 5, 2026.
What is GPT-5.3-Codex's context window?: GPT-5.3-Codex has a 400K-token context window and can generate up to 128K output tokens.
How does GPT-5.3-Codex score on benchmarks?: GPT-5.3-Codex has 9 cited benchmark scores, including SWE-bench Verified (Epoch AI run) 74.8%, Vending-Bench 2 (Andon Labs) 5940.12 and WeirdML (Håvard Tveit Ihle) 79.3%. Each score links to its source.

Access GPT-5.3-Codex and every other model through one endpoint with automatic failover: Respan gateway.