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.

GPT-6 LunaOpenAI Remove
Claude Sonnet 5.5Anthropic Remove
S1Fish Audio Remove
Universal-3.5 ProAssemblyAI Remove

4 is the maximum. Remove one to add another.

gpt-6-luna vs claude-sonnet-5.5 vs s1 vs universal-3-5-pro
Attribute	GPT-6 Lunagpt-6-luna	Claude Sonnet 5.5claude-sonnet-5.5	S1s1	Universal-3.5 Prouniversal-3-5-pro
Pricing
Input	$0.10 / 1M	$2.00 / 1M	$0 / 1M	$0 / 1M
Output	$0.50 / 1M	$10.00 / 1M	$0 / 1M	$0 / 1M
Cache Write (5m)	$0.10 / 1M	$2.50 / 1M	Not applicable	Not applicable
Cache Write (1h)	$0.10 / 1M	$4.00 / 1M	Not applicable	Not applicable
Cache Read	$0.10 / 1M	$0.20 / 1M	Not applicable	Not applicable
Web Search	$0 / 1M	$0 / 1M	$0 / 1M	$0 / 1M
Context
Max context	1.1M	1M	N/A	N/A
Max output	N/A	N/A	N/A	N/A
Capabilities
Vision	Yes	Yes	No	No
Function Calling	Yes	Yes	No	No
JSON Mode	Yes	Yes	No	No
Streaming	Yes	Yes	No	No
Catalogue
Provider	OpenAI	Anthropic	Fish Audio	AssemblyAI
Category	chat	chat	voice	voice
Charge type	Pay As You Go	Pay As You Go	Pay As You Go	Pay As You Go
Released	—	—	2026-07-29	2026-09-22
Description
Summary	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.	Claude 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 S1 text-to-speech. Billed per UTF-8 byte of input text.	AssemblyAI Universal-3.5 Pro speech-to-text. Billed per second of audio.