# OpenAI Releases GPT Astra > Source: > Published: 2026-09-03 15:09:14+00:00 # Models ## Choosing a model If you're not sure where to start, use [GPT-5.6 Sol](/api/docs/models/gpt-5.6-sol), our flagship model for complex reasoning and coding. Choose [GPT-5.6 Terra](/api/docs/models/gpt-5.6-terra) to balance intelligence and cost, or [GPT-5.6 Luna](/api/docs/models/gpt-5.6-luna) for cost-sensitive, high-volume workloads. All latest OpenAI models support text and image input, text output, multilingual capabilities, and vision. Models are available via the [Responses API](/api/docs/api-reference/responses) and our [Client SDKs](/api/docs/libraries). ## Flagship models Start with GPT-5.6 Sol for complex reasoning and coding, choose GPT-5.6 Terra to balance intelligence and cost, or use GPT-5.6 Luna for cost-sensitive, high-volume workloads. ## Specialized models Purpose-built for specific tasks. OpenAI Daybreak Advanced cyber models for defenders GPT-5.6 Cyber Our most advanced cybersecurity model for authorized vulnerability research and security testing. Daybreak Red An alias for advanced cybersecurity models for authorized vulnerability research and security testing. Daybreak Blue An alias for flagship general-purpose models with safeguards for defensive cybersecurity work. Image Models for image generation and editing Realtime Models for realtime speech and translation GPT-Realtime-2.1 Reasoning model with tool use GPT-Realtime-2.1 Mini Reasoning model with tool use GPT-Realtime-2 Reasoning model with tool use GPT-Realtime-Translate Streaming speech-to-speech translation model GPT-Realtime-1.5 The best voice model for audio in, audio out GPT-Realtime Mini Deprecated A cost-efficient version of GPT-Realtime Speech generation Models for generating natural-sounding speech from text Transcription Models for transcribing speech into text GPT-Transcribe High-accuracy speech-to-text model for file and Realtime input transcription GPT-Live-Transcribe Low-latency speech-to-text model for realtime transcription GPT-Realtime-Whisper Streaming speech-to-text model for realtime transcription GPT-4o Transcribe Speech-to-text model powered by GPT-4o GPT-4o Mini Transcribe Speech-to-text model powered by GPT-4o Mini ## Browse our full catalog of models Diverse models for a variety of tasks