Head-to-head comparison across 4benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Claude Fable 5
96
Claude Opus 4.8
94
Verified leaderboard positions: Claude Fable 5 #2 · Claude Opus 4.8 #5
Pick Claude Fable 5 if you want the stronger benchmark profile. Claude Opus 4.8 only becomes the better choice if you want the cheaper token bill.
Agentic
+5.1 difference
Coding
+9.2 difference
Knowledge
+4.7 difference
Multimodal
+16.3 difference
Claude Fable 5
Claude Opus 4.8
$10 / $50
$5 / $25
N/A
N/A
N/A
N/A
1M+
1M
Pick Claude Fable 5 if you want the stronger benchmark profile. Claude Opus 4.8 only becomes the better choice if you want the cheaper token bill.
Claude Fable 5 has the cleaner provisional overall profile here, landing at 96 versus 94. It is a real lead, but still close enough that category-level strengths matter more than the headline number.
Claude Fable 5's sharpest advantage is in multimodal & grounded, where it averages 92.4 against 76.1. The single biggest benchmark swing on the page is SWE-bench Pro, 80% to 69.2%.
Claude Fable 5 is also the more expensive model on tokens at $10.00 input / $50.00 output per 1M tokens, versus $5.00 input / $25.00 output per 1M tokens for Claude Opus 4.8. That is roughly 2.0x on output cost alone. Claude Fable 5 gives you the larger context window at 1M+, compared with 1M for Claude Opus 4.8.
Claude Fable 5 is ahead on BenchLM's provisional leaderboard, 96 to 94. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 80% and 69.2%.
Claude Fable 5 has the edge for knowledge tasks in this comparison, averaging 74.8 versus 70.1. Inside this category, HLE w/o tools is the benchmark that creates the most daylight between them.
Claude Fable 5 has the edge for coding in this comparison, averaging 85.6 versus 76.4. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.
Claude Fable 5 has the edge for agentic tasks in this comparison, averaging 85.2 versus 80.1. Inside this category, GDPval-AA is the benchmark that creates the most daylight between them.
Claude Fable 5 has the edge for multimodal and grounded tasks in this comparison, averaging 92.4 versus 76.1. Inside this category, CharXiv w/o tools is the benchmark that creates the most daylight between them.
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