The Model Index
Up to four models

Claude Opus 5.5 vs Claude Haiku 5.5

On the index (GPT-4 = 100), Claude Opus 5.5 scores 197 and Claude Haiku 5.5 174. Side by side on the same third-party tests, with price and context. The link in your address bar shares this exact comparison.

Next to Claude Opus 5.5
Presets
Claude Opus 5.5
197181–214
WeightsClosed
ReleasedSep 2026
Price in / out$4.0 / $20
Context1M
Core tests taken6 of 9
Claude Haiku 5.5
174158–191
WeightsClosed
ReleasedOct 2026
Price in / out$0.10 / $0.50
Context1M
Core tests taken7 of 9

Claude Opus 5.5 leads Claude Haiku 5.5 by 23 points, ahead on 6 of 6 shared core tests, at 40× the price.

Test by testthird-party results

Claude Opus 5.5Claude Haiku 5.5
0%25%50%75%100%REASONING & KNOWLEDGEGPQA Diamond (Epoch AI)GPQA Diamond (Epoch AI)LiveBench Data AnalysisLiveBench Data AnalysisLiveBench IFLiveBench IFLiveBench LanguageLiveBench LanguageLiveBench ReasoningLiveBench ReasoningEBR-benchEBR-benchSimpleQA VerifiedSimpleQA VerifiedMATHSFrontierMath (tiers 1-3)FrontierMath (tiers 1-3)AIME-style maths (OTIS mock)AIME-style maths (OTIS mock)LiveBench MathematicsLiveBench MathematicsProofBench v1.1ProofBench v1.1Chess puzzlesChess puzzlesFrontierMath (tier 4)FrontierMath (tier 4)CODINGTerminal-Bench 4.0Terminal-Bench 4.0LiveBench Agentic CodingLiveBench Agentic CodingLiveBench CodingLiveBench CodingCode MigrationCode MigrationCyberBench v1.1CyberBench v1.1IOIIOIProgramBenchProgramBenchVibe Code Bench 1-100Vibe Code Bench 1-100Vibe Code Bench v1.1Vibe Code Bench v1.1FrontierSWEFrontierSWEAGENTSAPEX-AgentsAPEX-AgentsBioMysteryBenchBioMysteryBenchSRE BenchSRE BenchTerminal-Bench-ScienceTerminal-Bench-ScienceDTBenchDTBenchFurniture assemblyFurniture assemblyLMCALMCAMystery game puzzlesMystery game puzzlesPROFESSIONAL WORKFinance Agent (v2)Finance Agent (v2)EMBEMBHLAB-Vals-1.1HLAB-Vals-1.1Legal Research BenchLegal Research BenchMedCodeMedCodeMedScribeMedScribePublic Benefits Bench v1.1Public Benefits Bench v1.1SAGESAGETax Agent BenchTax Agent BenchNOVEL PROBLEMSARC-AGI-2ARC-AGI-2ARC-AGI-1ARC-AGI-1MysteryMechanismMysteryMechanism
Every result as a table
TestClaude Opus 5.5Claude Haiku 5.5
Reasoning & knowledge
GPQA Diamond (Epoch AI)90.6%89.6%
LiveBench Data Analysis80.3%72.8%
LiveBench IF67.0%66.5%
LiveBench Language86.3%63.5%
LiveBench Reasoning92.2%84.6%
EBR-bench71.4%43.8%
SimpleQA Verified72.2%23.8%
Maths
FrontierMath (tiers 1-3)91.2%75.1%
AIME-style maths (OTIS mock)100.0%98.9%
LiveBench Mathematics97.1%92.8%
ProofBench v1.1100.0%89.0%
Chess puzzles67.0%55.0%
FrontierMath (tier 4)95.0%46.3%
Coding
Terminal-Bench 4.065.1%36.4%
LiveBench Agentic Coding71.7%57.2%
LiveBench Coding89.3%77.9%
Code Migration66.6%44.6%
CyberBench v1.174.6%75.5%
IOI95.1%47.3%
ProgramBench18.5%2.5%
Vibe Code Bench 1-10030.4%20.4%
Vibe Code Bench v1.190.3%90.4%
FrontierSWE62.3%43.8%
Agents
APEX-Agents73.5%56.1%
BioMysteryBench79.3%70.4%
SRE Bench33.6%5.7%
Terminal-Bench-Science47.1%10.0%
DTBench98.9%95.0%
Furniture assembly83.3%47.5%
LMCA68.2%51.1%
Mystery game puzzles71.0%30.0%
Professional work
Finance Agent (v2)58.6%54.1%
EMB75.9%59.0%
HLAB-Vals-1.19.2%4.2%
Legal Research Bench50.5%43.8%
MedCode49.8%51.5%
MedScribe91.4%89.5%
Public Benefits Bench v1.170.6%63.2%
SAGE45.8%45.8%
Tax Agent Bench45.6%31.9%
Novel problems
ARC-AGI-293.3%61.3%
ARC-AGI-198.5%89.0%
MysteryMechanism49.5%35.1%

Tests at least two of these models have taken. Bold rows are the core tests.

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