Head-to-head comparison across 4benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Claude Fable 5
96
Claude Opus 4.5
76
Verified leaderboard positions: Claude Fable 5 #2 · Claude Opus 4.5 #15
Pick Claude Fable 5 if you want the stronger benchmark profile. Claude Opus 4.5 only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.
Agentic
+22.7 difference
Coding
+19.7 difference
Knowledge
+8.6 difference
Multimodal
+22.4 difference
Claude Fable 5
Claude Opus 4.5
$10 / $50
$5 / $25
N/A
46 t/s
N/A
1.01s
1M+
200K
Pick Claude Fable 5 if you want the stronger benchmark profile. Claude Opus 4.5 only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.
Claude Fable 5 is clearly ahead on the provisional aggregate, 96 to 76. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Fable 5's sharpest advantage is in agentic, where it averages 85.2 against 62.5. The single biggest benchmark swing on the page is HLE, 64.5% to 30.8%.
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 4.5. That is roughly 2.0x on output cost alone. Claude Fable 5 is the reasoning model in the pair, while Claude Opus 4.5 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Claude Fable 5 gives you the larger context window at 1M+, compared with 200K for Claude Opus 4.5.
Claude Fable 5 is ahead on BenchLM's provisional leaderboard, 96 to 76. The biggest single separator in this matchup is HLE, where the scores are 64.5% and 30.8%.
Claude Fable 5 has the edge for knowledge tasks in this comparison, averaging 74.8 versus 66.2. Inside this category, HLE 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 65.9. 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 62.5. 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 70. Inside this category, CharXiv is the benchmark that creates the most daylight between them.
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