AIImportance: Medium

Claude Fable 5 was faster but cost more in a MineBench test

r/ClaudeAIJun 12, 2026 · 4h ago

A Reddit user says they compared Claude Fable 5 with Claude Opus 4.8 on MineBench. Fable 5 averaged 18 minutes and 4 seconds across 15 builds, while Opus 4.8 averaged 24 minutes and 48 seconds. The total cost was $54.93 for Fable 5 and $41.52 for Opus 4.8. The writer says Fable 5 may have cost less than expected because it produced fewer tokens overall.

Key points

  • Fable 5 averaged 18 minutes and 4 seconds per build in the test.
  • Opus 4.8 averaged 24 minutes and 48 seconds per build.
  • Fable 5 cost $54.93 for 15 builds.
  • Opus 4.8 cost $41.52 for the same 15 builds.
  • The writer says Fable 5 seemed to produce fewer tokens overall.

Quick term guide

Claude Fable 5
The name of an AI tool or model mentioned in the post, but the item does not give enough information to verify details.
Claude Fable
A new Claude AI model released by Anthropic in June 2026
Claude Opus 4.8
A new high-end Claude AI model from Anthropic.
Claude Opus
Claude Opus is a high-end AI model from Anthropic.
Opus 4.8
A high-end Claude AI model named by the project.
MineBench
A test used to compare how well AI models complete Minecraft-style building tasks.
Solo developer
An individual who handles all parts of creating a project or product alone.
web app
An app you use in a web browser instead of installing it.
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