Claude Fable 5.2 vs Claude Opus 5.5
Wins 4 of 6 areas
Coding · Reasoning · Facts · Math
Wins 1 of 6 areas
Long documents
Claude Fable 5.2 is the stronger all-rounder.Claude Opus 5.5 is cheaper and better at long documents.
Both rank among the ten best models we track in math.
Scores updated · 36 tests both models report · How we compare
Where each one wins
Tests won in each of the six areas where both have results. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
- CodingWriting and fixing software20Claude Fable 5.22 of 3 tests · 1 tie
- ReasoningHard problems that need careful thinking20Claude Fable 5.22 of 3 tests · 1 tie
- MathCompetition and research-level math20Claude Fable 5.22 of 2 tests
- FactsGetting facts right instead of making them up10Claude Fable 5.21 of 1 test
- Long documentsFinding answers in very long texts01Claude Opus 5.51 of 1 test
- AgentsCarrying out multi-step tasks on its own00Even0 each · 1 tie
Agents, facts and long documents rest on a single test each.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
Claude Opus 5.5 costs 50% less for the same work.
The biggest differences
The tests each model wins by the widest margin, up to three each. Scores are out of 100.
Where Claude Fable 5.2 pulls ahead
- Short factual questions, answered correctlySimpleQA Verified+21.8points ahead
- Very hard expert questions across many subjectsHumanity's Last Exam+12.9points ahead
- Extremely hard research-level math problemsFrontierMath Tier 4+5points ahead
Where Claude Opus 5.5 pulls ahead
- Reasons across sets of long documentsAA-LCR+1.4points ahead
Every test, side by side
All 36 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Fable 5.2
- SWE-bench ProClaude Fable 5.2 by 3.19389.9+3.1
- SWE-bench MultilingualClaude Fable 5.2 by 2.796.693.9+2.7
- SciCodetie67.766.9tie
ReasoningClaude Fable 5.2
- Humanity's Last ExamClaude Fable 5.2 by 12.974.361.4+12.9
- CritPtClaude Fable 5.2 by 3.735.431.7+3.7
- ARC-AGI-2tie92.591.7tie
MathClaude Fable 5.2
- FrontierMath Tier 4Claude Fable 5.2 by 510095+5
- FrontierMath Tiers 1-3 (v2)Claude Fable 5.2 by 3.995.191.2+3.9
Other results25 tests, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- Terminal-Bench-Science 0.1Claude Fable 5.2 by 14.373.359+14.3
- SWE-bench MultimodalClaude Fable 5.2 by 12.774.161.4+12.7
- HLE-DiamondClaude Fable 5.2 by 12.380.267.9+12.3
- CritPt v2 HardClaude Fable 5.2 by 8.576.568+8.5
- HealthBench ProfessionalClaude Fable 5.2 by 7.867.759.9+7.8
- HealthBench Professional length-adjustedClaude Fable 5.2 by 7.867.759.9+7.8
- OSWorld 2.1 partialClaude Fable 5.2 by 7.589.381.8+7.5
- HLE (with tools)Claude Fable 5.2 by 6.574.267.7+6.5
- Program BenchClaude Opus 5.5 by 5.685.691.2+5.6
- OfficeQA ProClaude Fable 5.2 by 5.272.967.7+5.2
- OfficeQAClaude Fable 5.2 by 4.583.478.9+4.5
- GDPval-AA v2.1 (max effort)Claude Opus 5.5 by 35 rating points18311866+35 rating
- HealthBenchClaude Fable 5.2 by 2.659.657+2.6
- HealthBench length-adjustedClaude Fable 5.2 by 2.659.657+2.6
- OSWorld 2.1 offline set (partial score)Claude Fable 5.2 by 2.189.387.2+2.1
- GDP (Surge AI)Claude Opus 5.5 by 224.226.2+2
- GlobalMMLUClaude Fable 5.2 by 1.79694.3+1.7
- GMMLUClaude Fable 5.2 by 1.79694.3+1.7
- GDPval-AA 2.1Claude Opus 5.5 by 15 rating points18311846+15 rating
- OSWorld 2.1 offline set (strict pass rate)Claude Fable 5.2 by 1.454.653.2+1.4
- Terminal-Bench 4.0Claude Fable 5.2 by 1.267.666.4+1.2
- MILUClaude Fable 5.2 by 194.193.1+1
- ProgramBench (with context tokens remaining shown)tie91.691.1tie
- DeepSWE 1.1tie74.374.2tie
- ARC-AGI-1tie97.597.5tie
Questions people ask
Which is better, Claude Fable 5.2 or Claude Opus 5.5?
Claude Fable 5.2 wins four of the six areas where both have results: coding, reasoning, facts and math. Claude Opus 5.5 wins long documents, and costs 50% less. They are level on agents.
Which is better for coding?
Claude Fable 5.2. It wins 2 of the 3 coding tests both models report; Claude Opus 5.5 wins none, and 1 is a tie.
Which is cheaper?
Claude Fable 5.2 costs $8.00 per million input tokens and $40.00 per million output tokens; Claude Opus 5.5 costs $4.00 and $20.00. That makes Claude Opus 5.5 about 50% cheaper for the same work.
How do you compare the two?
We use the 36 benchmark tests both models have published scores on. The verdict counts the 11 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 25 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.