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 SolOpenAI Remove
S2 ProFish Audio Remove
S2.1 ProFish Audio Remove
Universal-3.5 ProAssemblyAI Remove

4 is the maximum. Remove one to add another.

gpt-6-sol vs s2-pro vs s2.1-pro vs universal-3-5-pro
Attribute	GPT-6 Solgpt-6-sol	S2 Pros2-pro	S2.1 Pros2.1-pro	Universal-3.5 Prouniversal-3-5-pro
Pricing
Input	$2.00 / 1M	$0 / 1M	$0 / 1M	$0 / 1M
Output	$10.00 / 1M	$0 / 1M	$0 / 1M	$0 / 1M
Cache Write (5m)	$2.00 / 1M	Not applicable	Not applicable	Not applicable
Cache Write (1h)	$2.00 / 1M	Not applicable	Not applicable	Not applicable
Cache Read	$2.00 / 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	Fish Audio	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	2026-07-29	2026-09-22
Description
Summary	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	Fish Audio S2 Pro text-to-speech. Billed per UTF-8 byte of input text.	Fish Audio S2.1 Pro text-to-speech. Billed per UTF-8 byte of input text.	AssemblyAI Universal-3.5 Pro speech-to-text. Billed per second of audio.