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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 SolOpenAIRemove
  2. Claude Opus 5.5AnthropicRemove
  3. GPT-6 LunaOpenAIRemove
  4. S2 ProFish AudioRemove

4 is the maximum. Remove one to add another.

gpt-6-sol vs claude-opus-5.5 vs gpt-6-luna vs s2-pro
AttributeGPT-6 Solgpt-6-solClaude Opus 5.5claude-opus-5.5GPT-6 Lunagpt-6-lunaS2 Pros2-pro
Pricing
Input$2.00 / 1M$4.00 / 1M$0.10 / 1M$0 / 1M
Output$10.00 / 1M$20.00 / 1M$0.50 / 1M$0 / 1M
Cache Write (5m)$2.00 / 1M$5.00 / 1M$0.10 / 1MNot applicable
Cache Write (1h)$2.00 / 1M$8.00 / 1M$0.10 / 1MNot applicable
Cache Read$2.00 / 1M$0.40 / 1M$0.10 / 1MNot applicable
Web Search$0 / 1M$0 / 1M$0 / 1M$0 / 1M
Context
Max context1.1M1M1.1MN/A
Max outputN/AN/AN/AN/A
Capabilities
VisionYesYesYesNo
Function CallingYesYesYesNo
JSON ModeYesYesYesNo
StreamingYesYesYesNo
Catalogue
ProviderOpenAIAnthropicOpenAIFish Audio
Categorychatchatchatvoice
Charge typePay As You GoPay As You GoPay As You GoPay As You Go
Released———2026-07-29
Description
SummaryGPT-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 applicationsClaude Opus 5.5 is Anthropic's flagship model for advanced reasoning, coding, and long-horizon agentic workflows, succeeding Opus 5. It excels at multi-step changes across large codebases, code review and bug detection, financial and scientific analysis, and understanding dense charts, diagrams, and screenshots, with stronger grounding when reporting figures and citing sources. Compared with Opus 5, it completes comparable tasks with fewer steps and lower token usage while providing clearer, more concise progress reporting. With adaptive thinking and configurable effort levels, Opus 5.5 can balance reasoning depth, latency, and cost, making it well suited for both demanding autonomous workflows and latency-sensitive professional tasks.GPT-6 Luna is the fast, cost-efficient model in OpenAI's GPT-6 series, optimized for high-volume and latency-sensitive workloads such as chat, classification, and lightweight agentic tasks. It combines low-cost, responsive inference with the GPT-6 family’s improvements in factual reliability and clear, concise communication. At higher reasoning effort, GPT-6 Luna can also handle complex software engineering and computer-use workflows that previously required a Sol-tier model, making it a versatile choice for scalable production applications that need to balance speed, cost, and capability.Fish Audio S2 Pro text-to-speech. Billed per UTF-8 byte of input text.