Where is the GPT-5.3-Codex documentation?

The GPT-5.3-Codex documentation on OpenRouter includes the GPT-5.4 Migration Guide cookbook. The quickstart covers API keys and your first request, and the API reference lists every parameter.

How much does GPT-5.3-Codex cost?

GPT-5.3-Codex costs $1.75/M input tokens and $14.00/M output tokens, with separate rates for Cache Read at $0.175/M tokens.

What is the context length of GPT-5.3-Codex?

GPT-5.3-Codex has a 400,000 token context window. It supports up to 128,000 completion tokens.

Does GPT-5.3-Codex support tool calling and structured outputs?

Yes. GPT-5.3-Codex accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.

What inputs and outputs does GPT-5.3-Codex support?

GPT-5.3-Codex accepts text, images, and files such as PDFs as input and returns text.

Which providers serve GPT-5.3-Codex?

GPT-5.3-Codex is served by 2 providers on OpenRouter: Azure and OpenAI. Requests are routed to the best available provider, with automatic failover to the others, and you can pin or exclude providers with provider routing.

When was GPT-5.3-Codex released?

GPT-5.3-Codex was released on February 24, 2026.

OpenAI: GPT-5.3-Codex

openai/gpt-5.3-codex

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GPT-5.3-Codex is OpenAI’s most advanced agentic coding model, combining the frontier software engineering performance of GPT-5.2-Codex with the broader reasoning and professional knowledge capabilities of GPT-5.2. It achieves state-of-the-art results on SWE-Bench Pro and strong performance on Terminal-Bench 2.0 and OSWorld-Verified, reflecting improved multi-language coding, terminal proficiency, and real-world computer-use skills. The model is optimized for long-running, tool-using workflows and supports interactive steering during execution, making it suitable for complex development tasks, debugging, deployment, and iterative product work.

Beyond coding, GPT-5.3-Codex performs strongly on structured knowledge-work benchmarks such as GDPval, supporting tasks like document drafting, spreadsheet analysis, slide creation, and operational research across domains. It is trained with enhanced cybersecurity awareness, including vulnerability identification capabilities, and deployed with additional safeguards for high-risk use cases. Compared to prior Codex models, it is more token-efficient and approximately 25% faster, targeting professional end-to-end workflows that span reasoning, execution, and computer interaction.

Modalities

In / out price

$1.75 / $14per 1M

Context

400K

Released

Feb 24, 2026

Providers

Different companies host the same model. OpenRouter routes your request to one of them based on the routing mode you pick: Balanced (price + speed), Nitro (fastest), or Floor (cheapest).

Latency / throughput


	$1.75	$14.00	$0.175	4.23s	59 tok/s	100.00%
	$1.75	$14.00	$0.175	5.62s	32 tok/s	100.00%
Not used in Standard routing:Why these endpoints are not used
Fast	$3.50	$28.00	$0.35	--	--	--

Input $1.75Output $14.00
59 tok/s100.00% uptime
Input $1.75Output $14.00
32 tok/s100.00% uptime
Not used in Standard routing:Why these endpoints are not used
Input $3.50Output $28.00
Fast
-- tok/s-- uptime

Pricing

The average price customers actually pay for this model, next to the prices providers post. Caching and discounts mean the price actually paid is often well below the listed one.

Weighted average

Input

$0.3333/M tokens

Output

$14/M tokens

GPT-5.3-Codex — Price history

Price history

No effective price data for this selection

		$0.315	$14.00	91.1%	65.2%
		$0.367	$14.00	87.8%	34.8%
Not used in Standard routing:Why these endpoints are not used
	Fast	$3.499	$28.00	0.0%	0.0%

Effective in $0.315Effective out $14.00
Token share
65.2%
Effective in $0.367Effective out $14.00
Token share
34.8%
Not used in Standard routing:Why these endpoints are not used
Effective in $3.499Effective out $28.00
FastToken share
0.0%

Uptime

Uptime is the percentage of the past 3 days that at least one provider was responding to requests. Availability is the percentage of time that inference was successfully served. OpenRouter continuously monitors and uses the next-best provider when one returns an error.

Uptime (3d)

100.00%

Availability (3d)

99.91%

Availability over the last 3 days

Last 72 hours

Availability 99.91%

3 Days Ago2 Days AgoYesterdayNow

Availability over the last 24 hours

OpenRouter Availability

99.89%

Without Routing

99.80%

When an error occurs in an upstream provider, we can recover by routing to another healthy provider, if your request filters allow it. You can access per-provider uptime data programmatically through the Endpoints API. Learn more about our load balancing and provider routing options.

Benchmarks

Scores on standardized evaluations and this model’s own outputs on shared benchmark prompts. Higher percentages are better — and each rank shows where this model lands among the models evaluated on that source.

Benchmark score summary for OpenAI: GPT-5.3-Codex (Artificial Analysis, Design Arena and Vals AI)
Source	Benchmark	Score
Artificial Analysis	GPT-5.3 Codex (Xhigh) GPQA Diamond	91.5%
Artificial Analysis	GPT-5.3 Codex (Xhigh) HLE	42.5%
Artificial Analysis	GPT-5.3 Codex (Xhigh) IFBench	75.4%
Artificial Analysis	GPT-5.3 Codex (Xhigh) τ²-Bench Telecom	86.0%
Artificial Analysis	GPT-5.3 Codex (Xhigh) AA-LCR	83.3%
Artificial Analysis	GPT-5.3 Codex (Xhigh) CritPt	16.9%
Artificial Analysis	GPT-5.3 Codex (Xhigh) Terminal-Bench Hard	53.0%
Design Arena	GPT-5.3 Codex Agents Arena Androidnative Elo	1084
Design Arena	GPT-5.3 Codex Agents Arena Full Stack Elo	962
Design Arena	GPT-5.3 Codex Agents Arena Godotgamedev Elo	1124
Design Arena	GPT-5.3 Codex Agents Arena Mobile Apps Elo	1047
Design Arena	GPT-5.3 Codex Agents Arena Webapps Elo	1010
Design Arena	GPT-5.3 Codex Models Arena 3D Elo	987
Design Arena	GPT-5.3 Codex Models Arena Asciiart Elo	1147
Design Arena	GPT-5.3 Codex Models Arena Code Categories Elo	1134
Design Arena	GPT-5.3 Codex Models Arena Data Visualization Elo	1162
Design Arena	GPT-5.3 Codex Models Arena Game Development Elo	1150
Design Arena	GPT-5.3 Codex Models Arena SVG Elo	1120
Design Arena	GPT-5.3 Codex Models Arena UI Component Elo	1128
Design Arena	GPT-5.3 Codex Models Arena Website Elo	1154
Vals AI	GPT 5.3 Codex IOI	53.8%
Vals AI	GPT 5.3 Codex LiveCodeBench	87.3%
Vals AI	GPT 5.3 Codex SWE-bench	78.0%
Vals AI	GPT 5.3 Codex Terminal-Bench 2.0	64.0%
Vals AI	GPT 5.3 Codex Vibe Code Bench v1.1	61.8%

Apps

Public apps that send the most traffic to this model. Good signal for what real production workloads look like — and a hint at which use cases this model is best suited for.

Framer

Create a professional website with Framer’s no-code AI website builder. Design freely, manage CMS content, optimize SEO, collaborate, and publish fast.

42.5Btokens

Ito

Agentic QA platform that actually runs your app

8.64Btokens

Codex

A coding agent that helps you build and ship with AI

4.5Btokens

Hermes Agent

Hermes Agent is an open-source, self-improving AI agent by Nous Research that runs persistently with memory across sessions, and builds reusable skills from experience. It comes with 40+ built-in tools, including web search, browser automation, and vision, plus scheduled automations and subagents.

2.05Btokens

Kilo Code

Kilo Code is an open-source AI coding agent that works across VS Code, JetBrains, and CLI to help developers ship code faster with agentic workflows.

1.68Btokens

Rest of OpenRouter

879M

Top 5 Apps

307M

Not currently available through EU in-region routing. In-region routing docs

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Providers