OpenAI's GPT-5.6 vs Anthropic's Fable 5: Which AI Wins?

Two of the biggest artificial intelligence companies are going head-to-head, and the results matter for anyone using AI tools. Here's what you need to know in plain English.

What changed? OpenAI (the maker of ChatGPT) just released GPT-5.6. Instead of one AI model, it now comes as three separate versions called Sol, Terra, and Luna. The main rival is Fable 5, made by another company called Anthropic.

Price is a big deal here. AI companies charge based on "tokens" (small chunks of text the AI reads or writes). Roughly, 1 million tokens equals about 750,000 words. Here's how the costs compare:

• GPT-5.6 Sol: $5 per million words read, $30 per million written
• Fable 5: $10 read, $50 written — twice as expensive
• GPT-5.6 Luna (cheapest): just $1 read, $6 written

Why this hurts Anthropic: The cheap Luna model already beats Anthropic's top coding model at a fraction of the cost. That makes OpenAI's budget option look better than a rival's premium product.

Fable 5 had a rough time recently:

• The U.S. government banned it on June 12 after researchers found a security flaw (a "jailbreak" that made the AI behave in dangerous, unintended ways).
• Anthropic pulled it worldwide for 19 days, fixed the safety issue, and brought it back July 1.
• Access keeps getting extended at the last minute — now through July 19.

How do they perform? In coding tests, Sol beat Fable 5 while using half the resources, half the time, and about a third of the cost. But on a broader intelligence test combining nine measures, Fable 5 won by just one point — meaning they're very close overall.

Creative writing test: Both models wrote a time-travel story. Reviewers felt Fable 5 told the more beautiful, culturally rich story, while Sol was clearer and easier to read.

The bottom line: GPT-5.6 offers better value for money, while Fable 5 still shines in quality. Which you pick depends on whether you care most about cost or polish.

This is an AI-generated summary. Read the original article at: https://decrypt.co/373770/openai-gpt-5-6-vs-anthropic-fable-5-review