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GPT-5.3-Codex-Spark

OpenAIProprietaryPending Human Review

GPT-5.3-Codex-Spark is the smaller coding model designed for near-instant interactive development. Its public research preview runs on Cerebras hardware through Codex for ChatGPT Pro subscribers, with separate usage limits. At launch it supported a 128K context and text-only input. It favors quick, targeted edits and does not automatically run tests unless asked, making it complementary to longer-horizon coding models.

2026-02-12
Unreleased
Undisclosed proprietary architecture
Proprietary

Specifications

Parameters
Unreleased
Architecture
Undisclosed proprietary architecture
License
Proprietary
Context Window
128,000 tokens
Type
text
Modalities
text

Benchmark Scores

Advanced Specifications

Model Family
GPT-5
API Access
Not Available
Chat Interface
Available
Hardware Support
Cerebras Wafer Scale Engine

Capabilities & Limitations

Capabilities
codeinteractive editinglow-latency reasoning
Known Limitations
Research preview with separate capacity and usage limits.Text-only input; lower capability than the full GPT-5.3-Codex model.Tests may need to be explicitly requested.
Notable Use Cases
rapid code editsinteractive developmenttargeted debugging

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