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
S2 ProFish Audio Remove
Nova-3Deepgram Remove
Universal-3.5 ProAssemblyAI Remove

4 is the maximum. Remove one to add another.

gpt-6-luna vs s2-pro vs nova-3 vs universal-3-5-pro
Attribute	GPT-6 Lunagpt-6-luna	S2 Pros2-pro	Nova-3nova-3	Universal-3.5 Prouniversal-3-5-pro
Pricing
Input	$0.10 / 1M	$0 / 1M	$0 / 1M	$0 / 1M
Output	$0.50 / 1M	$0 / 1M	$0 / 1M	$0 / 1M
Cache Write (5m)	$0.10 / 1M	Not applicable	Not applicable	Not applicable
Cache Write (1h)	$0.10 / 1M	Not applicable	Not applicable	Not applicable
Cache Read	$0.10 / 1M	Not applicable	Not applicable	Not applicable
Web Search	$0 / 1M	$0 / 1M	$0 / 1M	$0 / 1M
Context
Max context	1.1M	N/A	N/A	N/A
Max output	N/A	N/A	N/A	N/A
Capabilities
Vision	Yes	No	No	No
Function Calling	Yes	No	No	No
JSON Mode	Yes	No	No	No
Streaming	Yes	No	No	No
Catalogue
Provider	OpenAI	Fish Audio	Deepgram	AssemblyAI
Category	chat	voice	voice	voice
Charge type	Pay As You Go	Pay As You Go	Pay As You Go	Pay As You Go
Released	—	2026-07-29	2026-07-15	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.	Fish Audio S2 Pro text-to-speech. Billed per UTF-8 byte of input text.	Deepgram Nova-3 speech-to-text. Billed per second of audio.	AssemblyAI Universal-3.5 Pro speech-to-text. Billed per second of audio.