GPT-5.3-Codex-Spark
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