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Daniel Mac (@daniel_mac8) predicts GPT-5.6 will ship and Fable will return the…

2026-06-28 · 11:59 UTC ·@daniel_mac8 ·1 min read

Brief

Daniel Mac (@daniel_mac8) predicts GPT-5.6 will ship and Fable will return the week of 2026-06-28, citing Axios reporting that export controls on Fable may be lifted and the government won’t favor Anthropic over OpenAI. He frames Fable as the most capable but slow/expensive model, GPT-5.6 as nearly as capable and 40% cheaper per output token, and highlights combining Fable (coding) with GPT-5.6 (agentic experiments); tester Mikhail Parakhin corroborates 5.6 beating Opus 4.8 and being better at agentic tasks while Fable is stronger on coding.

Why it matters

Daniel Mac (@daniel_mac8) predicts GPT-5.6 will ship and Fable will return the week of 2026-06-28; Axios reportedly says the U.S. government may lift export controls on Fable as soon as that week and is unlikely to favor Anthropic over OpenAI.

Key details

  • Fable is claimed to be the most capable model but is slow and expensive; GPT-5.6 is described as nearly as capable and far more efficient, with output tokens costing 40% less than Fable's.
  • Independent tester Mikhail Parakhin reports GPT-5.6 (Max/Sol) outperforms Opus 4.8 across tasks (and is slightly faster depending on load), while Fable is stronger at coding and GPT-5.6 is stronger on agentic/experiment-running workloads—he used Fable to write code and 5.6 to run experiments.
Source evidence

My prediction: GPT-5.6 ships and Fable returns this week.

Axios reports the government will lift export controls on Fable as soon as this week, and they're unlikely to favor Anthropic over OpenAI.

Fable is the most capable model we have. It's also slow and expensive.

GPT-5.6 looks nearly as capable and far more efficient. Its output tokens cost 40% less than Fable's.

Some think GPT-5.6 Sol is the model that cracked the Erdős unit-distance problem. No slouch.

The exciting part is using Fable and GPT-5.6 Sol together.

Maybe this week, you can.

Mikhail Parakhin (@MParakhin)

Not as relevant now :-(: I had an opportunity to deeply test both Fable 5 and GPT-5.6 Max. 5.6 is clearly better than Opus 4.8 at everything (slightly faster, too, though that depends on the load). Vis-a-vie Fable, it is clearly worse on coding, but better on agentic workloads. I had Fable write code, 5.6 run experiments - dreamy…

— https://nitter.net/MParakhin/status/2070727777888985339#m