Claude Fable 5.1 vs Claude Opus 5: Specs & Benchmark Comparison
Claude Fable 5.1 and Claude Opus 5 both come from Anthropic, Claude Opus 5 was released in July 2026, and Claude Fable 5.1 followed 2 months later in September 2026.
The two models share 4 published benchmarks. Claude Fable 5.1 leads on 4 of them. The widest gaps are on OSWorld 2.0, where Claude Fable 5.1 scores 77.9% against 70.6%; AutomationBench, where Claude Fable 5.1 scores 31.4% against 26.0%. Averaged across everything we track, Claude Fable 5.1 sits at 59.7% and Claude Opus 5 at 55.0%.
Claude Opus 5 is the cheaper API at $5 per million input tokens and $25 per million output tokens, roughly 2 times cheaper than Claude Fable 5.1 at $10 and $50. Both accept a context window of about 1M tokens. Both accept text and images as input.
| Characteristic | Claude Fable 5.1 | Claude Opus 5 |
|---|---|---|
| Company | Anthropic | Anthropic |
| Release Date | September 1, 2026 | July 24, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 1.0M |
| Context (output) | 128K | 128K |
| Input Price / 1M | $10.00 | $5.00 |
| Output Price / 1M | $50.00 | $25.00 |
| Average Score | 59.7% | 55.0% |
| Benchmarks | ||
| OSWorld 2.0 | 77.9% | 70.6% |
| AutomationBench | 31.4% | 26.0% |
| Terminal-Bench 4.0 | 55.8% | 51.8% |
| Humanity's Last Exam | 65.0% | 64.7% |
Visual Benchmark Comparison
Verdict
Both models show equal results — the choice depends on your specific use case.
Both models show comparable average scores: Claude Fable 5.1 — 0.6, Claude Opus 5 — 0.5.
Claude Opus 5 is 2.0x cheaper: input $5.00/1M vs $10.00/1M tokens.
Same context size: 1M tokens.
Claude Fable 5.1 is newer: released 9/1/2026 vs 7/24/2026.
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Frequently Asked Questions
Which is better for coding — Claude Fable 5.1 or Claude Opus 5?
Which model is cheaper — Claude Fable 5.1 or Claude Opus 5?
Which has a larger context window — Claude Fable 5.1 or Claude Opus 5?
The Claude Fable 5.1 and Claude Opus 5 comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Claude Fable 5.1 or Claude Opus 5 page. See also the complete list of AI model comparisons.