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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. Claude Sonnet 5.5AnthropicRemove
  2. S2 ProFish AudioRemove
  3. GPT-6 Luna ProOpenAIRemove
  4. S2.1 ProFish AudioRemove

4 is the maximum. Remove one to add another.

claude-sonnet-5.5 vs s2-pro vs gpt-6-luna-pro vs s2.1-pro
AttributeClaude Sonnet 5.5claude-sonnet-5.5S2 Pros2-proGPT-6 Luna Progpt-6-luna-proS2.1 Pros2.1-pro
Pricing
Input$2.00 / 1M$0 / 1M$0.10 / 1M$0 / 1M
Output$10.00 / 1M$0 / 1M$0.50 / 1M$0 / 1M
Cache Write (5m)$2.50 / 1MNot applicable$0.10 / 1MNot applicable
Cache Write (1h)$4.00 / 1MNot applicable$0.10 / 1MNot applicable
Cache Read$0.20 / 1MNot applicable$0.10 / 1MNot applicable
Web Search$0 / 1M$0 / 1M$0 / 1M$0 / 1M
Context
Max context1MN/A1.1MN/A
Max outputN/AN/AN/AN/A
Capabilities
VisionYesNoYesNo
Function CallingYesNoYesNo
JSON ModeYesNoYesNo
StreamingYesNoYesNo
Catalogue
ProviderAnthropicFish AudioOpenAIFish Audio
Categorychatvoicechatvoice
Charge typePay As You GoPay As You GoPay As You GoPay As You Go
Released—2026-07-29—2026-07-29
Description
SummaryClaude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, serving as a direct upgrade to Sonnet 5. It excels at feature development, bug fixing, and creating polished documents, presentations, and spreadsheets, while offering clearer writing and communication than its predecessor.Fish Audio S2 Pro text-to-speech. Billed per UTF-8 byte of input text.GPT-6 Luna Pro uses the same underlying model as GPT-6 Luna, but runs with reasoning.mode set to pro for higher-quality responses on complex tasks. It combines Luna's speed and cost efficiency with deeper reasoning and more reliable multi-step execution, making it well suited for advanced coding, computer use, and agentic workflows where higher solution quality is needed without moving to a larger GPT-6 tier.Fish Audio S2.1 Pro text-to-speech. Billed per UTF-8 byte of input text.