What is the difference between GPT-5.6 Terra and Muse Spark 1.3?

GPT-5.6 Terra is developed by OpenAI while Muse Spark 1.3 is developed by Meta AI. GPT-5.6 Terra has a 1.1M token context window vs Muse Spark 1.3's 1.0M. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.6 Terra or Muse Spark 1.3?

It depends on your use case. GPT-5.6 Terra and Muse Spark 1.3 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 54 challenges so you can judge which fits your needs best.

How much does GPT-5.6 Terra cost compared to Muse Spark 1.3?

GPT-5.6 Terra costs $2.5/M input tokens and Muse Spark 1.3 costs $1.25/M input tokens. Muse Spark 1.3 is $1.25/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare GPT-5.6 Terra and Muse Spark 1.3 on Rival?

This page shows a side-by-side comparison of GPT-5.6 Terra and Muse Spark 1.3 across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

Updated Sep 2026

GPT-5.6 TerravsMuse Spark 1.3

Muse Spark 1.3 is cheaper than GPT-5.6 Terra at $1.25/M vs $2.5/M input tokens.

GPT-5.6 Terra and Muse Spark 1.3 compared across 54 shared prompts
Spec	GPT-5.6 Terra	Muse Spark 1.3
Input price	$2.5/M tokens	$1.25/M tokens
Output price	$15/M tokens	$4.25/M tokens
Context window	1.1M tokens	1.0M tokens
Weights	Closed	Closed
Free API (OpenRouter)	No	No
Released	Jul 2026	Sep 2026