Claude Fable 5.1 vs Claude Sonnet 5: Specs & Benchmark Comparison

CharacteristicClaude Fable 5.1Claude Sonnet 5
CompanyAnthropicAnthropic
Release DateSeptember 1, 2026June 30, 2026
Parameters
MultimodalYesYes
Context (input)1.0M1.0M
Context (output)128K64K
Input Price / 1M$10.00$2.00
Output Price / 1M$50.00$10.00
Average Score0.60.6
Benchmarks
AutomationBench0.30.1
Humanity's Last Exam0.70.6

Visual Benchmark Comparison

Claude Fable 5.1
Claude Sonnet 5
AutomationBench0.3 vs 0.1
0.3
0.1
Humanity's Last Exam0.7 vs 0.6
0.7
0.6

Verdict

Claude Fable 5.1 leads in 2 out of 4 comparison categories.

Overall Performance

Both models show comparable average scores: Claude Fable 5.1 — 0.6, Claude Sonnet 5 — 0.6.

API Cost

Claude Sonnet 5 is 5.0x cheaper: input $2.00/1M vs $10.00/1M tokens.

Context Window

Claude Fable 5.1 supports a larger context: 1M vs 1M tokens.

Recency

Claude Fable 5.1 is newer: released 9/1/2026 vs 6/30/2026.

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Frequently Asked Questions

Which is better for coding — Claude Fable 5.1 or Claude Sonnet 5?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — Claude Fable 5.1 or Claude Sonnet 5?
Claude Sonnet 5 is cheaper for input: $2.00 per 1M tokens vs $10.00.
Which has a larger context window — Claude Fable 5.1 or Claude Sonnet 5?
Claude Fable 5.1 supports a larger context: 1,048,576 tokens vs 1,000,000.

The Claude Fable 5.1 and Claude Sonnet 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 Sonnet 5 page. See also the complete list of AI model comparisons.