Identity
- Status
- active
- Developer ID
gpt-5.3-codex- Released
- Not reported
- Version
- GPT-5.3-Codex
- License
- Unknown
OpenAIGPT-5.3 Codex
GPT-5.3-Codex is an OpenAI model optimized for long-horizon agentic coding in Codex-like environments.
- Token context
- 400K tokens
- Inputs
- Text, Image
- Outputs
- Text
- Released
- Not reported
Providers & Pricing
Estimate workload cost →| Provider | Input / 1M | Output / 1M | Cache read / 1M | Cache write / 1M | Observed | Evidence |
|---|---|---|---|---|---|---|
OpenaiAvailable | $1.75 | $14.00 | $0.175 | — | Sep 3, 2026 | Provider-reported |
 OpenrouterAvailable | $1.75 | $14.00 | $0.175 | — | Sep 4, 2026 | Provider-reported |
At a Glance
Model Facts
Capacity
- Token context
- 400K tokens
- Maximum output
- 128K tokens
- Total parameters
- Unknown
- Active parameters
- Unknown
- Knowledge cutoff
- Aug 31, 2025
Interface and Access
- Inputs
- Text, Image
- Outputs
- Text
- API available
- Yes
- Open weights
- No
- Self-hostable
- No
- Reasoning
- Yes
- Vision
- Yes
- Tool calling
- Yes
- Capabilities
- chat, generation, reasoning, structured outputs, tools
This page represents one developer model product. Dated API snapshots, serving endpoints, pricing, regions, quantizations, and service tiers attach as versioned aliases or provider details and never create duplicate public model records.
Version Lineage
PredecessorUnknown
SuccessorsUnknown
Aliasesgpt-5.3-codex
Explicit Unknowns
- Release date
- Architecture
- Tokenizer
Primary Evidence
Sources and Observation Date
Comparable Peers
Related Model Comparisons
| A | Pair | B | Context |
|---|---|---|---|
GPT-5.3 CodexOpenAI | vs | GPT-6 AstraOpenAI | family variantsimage, text |
GPT-5.3 CodexOpenAI | vs | Claude Fable 5.1Anthropic | cross-developer peersimage, text |
GPT-5.3 CodexOpenAI | vs |  Gemini 3.1 ProGoogle DeepMind | cross-developer peerstext |
GPT-5.3 CodexOpenAI | vs |  DeepSeek V4 ProDeepSeek | cross-developer peerstext |
GPT-5.3 CodexOpenAI | vs | Grok 4.6xAI | cross-developer peersimage, text |
GPT-5.3 CodexOpenAI | vs |  Qwen3.8 MaxQwen | cross-developer peersimage, text |
GPT-5.3 CodexOpenAI | vs |  Kimi K3Moonshot AI | cross-developer peersimage, text |
GPT-5.3 CodexOpenAI | vs |  MiniMax M3MiniMax | cross-developer peersimage, text |
GPT-5.3 CodexOpenAI | vs |  GLM 5.3Z.ai | cross-developer peerstext |
GPT-5.3 CodexOpenAI | vs |  Hy4 previewTencent | cross-developer peerstext |
GPT-5.3 CodexOpenAI | vs | Seed 2.1 ProByteDance Seed | cross-developer peersimage, text |
GPT-5.3 CodexOpenAI | vs |  Mistral Large 3Mistral AI | cross-developer peersimage, text |
GPT-5.3 CodexOpenAI | vs | cross-developer peersimage, text | |
GPT-5.3 CodexOpenAI | vs |  Nova 2 LiteAmazon | cross-developer peersimage, text |
GPT-5.3 CodexOpenAI | vs | cross-developer peersimage, text | |
GPT-5.3 CodexOpenAI | vs |  ERNIE 5.1Baidu | cross-developer peerstext |
GPT-5.3 CodexOpenAI | vs | cross-developer peerstext | |
GPT-5.3 CodexOpenAI | vs | cross-developer peerstext | |
GPT-5.3 CodexOpenAI | vs |  Phi-4 ReasoningMicrosoft | cross-developer peerstext |
GPT-5.3 CodexOpenAI | vs | cross-developer peerstext | |
GPT-5.3 CodexOpenAI | vs |  Sonar ProPerplexity | cross-developer peerstext |
GPT-5.3 CodexOpenAI | vs | cross-developer peersimage, text |
Questions
GPT-5.3 Codex FAQs
What is GPT-5.3 Codex?+
GPT-5.3-Codex is an OpenAI model optimized for long-horizon agentic coding in Codex-like environments. It is developed by OpenAI and its current sourced lifecycle status is active.
What inputs and outputs does GPT-5.3 Codex support?+
GPT-5.3 Codex's current record lists Text and Image as input and Text as output.
How much context does GPT-5.3 Codex support?+
The current record lists a 400K-token context window and a maximum output of 128K tokens.
Is GPT-5.3 Codex available through an API?+
GPT-5.3 Codex is marked as API-available. The directly sourced provider records currently include Openai and Openrouter.
How much does GPT-5.3 Codex cost through an API?+
The lowest directly sourced prices currently attached to GPT-5.3 Codex are $1.75 per million input tokens through Openai and $14.00 per million output tokens through Openai. Prices are provider-specific and should be checked against each cited observation date.
What capabilities and tasks does GPT-5.3 Codex support?+
GPT-5.3 Codex's recorded capabilities are chat, generation, reasoning, structured outputs, and tools. Its supported tasks are image, reasoning, and text.
Can GPT-5.3 Codex be self-hosted?+
GPT-5.3 Codex is not marked as an open-weight model. Self-hosting is marked as unsupported, with no license recorded.
Does GPT-5.3 Codex have related versions or aliases?+
No predecessor is recorded. No successor is recorded. Recorded aliases are gpt-5.3-codex.
Which models can GPT-5.3 Codex be compared with?+
The current compatible peer set includes GPT-6 Astra, Claude Fable 5.1, Gemini 3.1 Pro, DeepSeek V4 Pro, and Grok 4.6. Compatibility requires shared sourced modalities and tasks; it does not imply that one model is better. Browse model comparisons →
How current is the Model Markets record for GPT-5.3 Codex?+
GPT-5.3 Codex was last verified Sep 3, 2026 from OpenAI's primary source, “GPT-5.3-Codex Model | OpenAI API.” The evidence is classified as official fact.