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Compare models

Put up to 4 models beside each other — token prices, context windows, capabilities and provider, from the same catalogue the model pages read.

  1. GPT-6 AstraOpenAIRemove
  2. Universal-3.5 ProAssemblyAIRemove
  3. S1Fish AudioRemove
  4. GPT-6 SolOpenAIRemove

4 is the maximum. Remove one to add another.

gpt-6-astra vs universal-3-5-pro vs s1 vs gpt-6-sol
AttributeGPT-6 Astragpt-6-astraUniversal-3.5 Prouniversal-3-5-proS1s1GPT-6 Solgpt-6-sol
Pricing
Input$10.00 / 1M$0 / 1M$0 / 1M$2.00 / 1M
Output$50.00 / 1M$0 / 1M$0 / 1M$10.00 / 1M
Cache Write (5m)$10.00 / 1MNot applicableNot applicable$2.00 / 1M
Cache Write (1h)$10.00 / 1MNot applicableNot applicable$2.00 / 1M
Cache Read$10.00 / 1MNot applicableNot applicable$2.00 / 1M
Web Search$0 / 1M$0 / 1M$0 / 1M$0 / 1M
Context
Max context1MN/AN/A1.1M
Max outputN/AN/AN/AN/A
Capabilities
VisionYesNoNoYes
Function CallingYesNoNoYes
JSON ModeYesNoNoYes
StreamingYesNoNoYes
Catalogue
ProviderOpenAIAssemblyAIFish AudioOpenAI
Categorychatvoicevoicechat
Charge typePay As You GoPay As You GoPay As You GoPay As You Go
Released—2026-09-222026-07-29—
Description
SummaryGPT-6 Astra is OpenAI's flagship model for demanding end-to-end professional work, designed for advanced analysis, software engineering, deep research, scientific tasks, and document creation. It is particularly strong in long-horizon agentic workflows, including tasks that require sustained reasoning, tool orchestration, and computer and browser use, making it well suited for complex autonomous workflows and production-grade knowledge work.AssemblyAI Universal-3.5 Pro speech-to-text. Billed per second of audio.Fish Audio S1 text-to-speech. Billed per UTF-8 byte of input text.GPT-6 Sol is OpenAI's cost-efficient high-end model in the GPT-6 series, positioned between the flagship GPT-6 Astra and the fast GPT-6 Luna tier. It is designed for professional knowledge work, agentic coding, business workflow automation, and computer-use tasks, with particular strength in long-horizon software engineering across real-world codebases. GPT-6 Sol approaches Astra-level factual reliability at a significantly lower cost, while sharing its clear and concise communication style. This balance of capability, reliability, and efficiency makes it well suited for production agents, complex engineering workflows, and scalable professional applications