Claude Fable 5 vs GPT-5.6 Terra
Anthropic Claude Fable 5 | OpenAI GPT-5.6 Terra | |
|---|---|---|
| Overview | ||
| Company | Anthropic | OpenAI |
| Release date | Jun 9 2026 | Jun 26 2026 |
| Access | Proprietary | Proprietary |
| Specifications | ||
Context window | 1M | — |
| Benchmarks | ||
Nonsense detection BullshitBench v2Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | 56% | — |
Agentic coding SWE-Bench ProCan the AI fix real bugs in real software? It's handed actual problems from open-source projects and has to write code that genuinely solves them. Higher is better. | 80.3% | — |
Coding SWE-Bench VerifiedReal coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. | 95.5% | — |
Agentic terminal coding Terminal-Bench 2.1Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? Higher is better. | 88% | — |
Agentic computer use OSWorld-VerifiedCan the AI actually operate a computer — clicking, typing, and using real apps — to finish tasks on its own? Higher is better. | 85% | — |
Knowledge work GDPval-AAMeasures how well the AI does economically valuable knowledge work, judged against human experts. Shown as a rating (like a chess Elo) — higher is better. | 1932 | — |
| Timeline | ||
| Release gap | Claude Fable 5 shipped 17 days before GPT-5.6 Terra | |
Which is better: Claude Fable 5 or GPT-5.6 Terra?
Claude Fable 5 and GPT-5.6 Terra don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude Fable 5 shipped 17 days before GPT-5.6 Terra, so benchmark comparisons should account for the intervening progress.
Published specifications for these two models are limited — see each model page for the latest details.
Direct benchmark comparisons are unavailable — Claude Fable 5 and GPT-5.6 Terra don't publish scores on any of the same benchmarks.
Frequently asked questions
Claude Fable 5 was released by Anthropic on Jun 9 2026.
GPT-5.6 Terra was released by OpenAI on Jun 26 2026.
Other comparisons
Claude Fable 5 vs Gemini OmniGPT-5.6 Terra vs Gemini OmniClaude Fable 5 vs Muse SparkGPT-5.6 Terra vs Muse SparkClaude Fable 5 vs Grok 4.3 BetaGPT-5.6 Terra vs Grok 4.3 BetaClaude Fable 5 vs DeepSeek-V4-ProGPT-5.6 Terra vs DeepSeek-V4-ProClaude Fable 5 vs Mistral Medium 3.5GPT-5.6 Terra vs Mistral Medium 3.5Claude Fable 5 vs Kimi K2.7 CodeGPT-5.6 Terra vs Kimi K2.7 Code