Claude Opus 4.5 vs Claude Sonnet 4.5

Verdict

Claude Opus 4.5 leads 23–0 across 24 shared benchmarks.

Claude Opus 4.5 23 · Claude Sonnet 4.5 0 · 1 tied · higher isn't always better — check the caveats below.

Per-benchmark head-to-head

Reported scores — protocols may differ. How we compare

Sort

Claude Opus 4.5Claude Sonnet 4.5

80
BARC-AGI
63.67
37.64
AARC-AGI-2
13.61
7.41
AChess Puzzles
7.41
82
BCybench
60
14.29
AEBR-bench
2.38
4.88
AFrontierMath-Tier-4-v2-Private
2.44
34.39
AFrontierMath-Tiers-1-3-v2-Private
23.86
45.5
AGDPval
42.5
81.4
BGPQA diamond
76.43
26.5
AGSO-Bench
14.71
21.43
AHLE
9.37
74.97
AMETR Time Horizons
67.38
14.08
AMystery Game Puzzles
8.57
66.3
BOSWorld
62.9
86.1
AOTIS Mock AIME 2024-2025
77.76
17.29
APostTrainBench
9.94
36
AProofBench
19
3.75
BRemote Labor Index
2.08
54.4
ASimpleBench
45.16
41.8
ASimpleQA Verified
23.6
76.65
BSWE-Bench verified
71.28
63.1
BTerminal Bench
46.5
10
AVPCT
9.7
63.7
AWeirdML
47.71

Capabilities

Reasoning

Reasoning: Claude Opus 4.5 leads 5–0 across 5 shared reasoning benchmarks (largest gap: SimpleQA Verified, 41.8 vs 23.6 — single evaluator).

4 reproduced6 unverified

Unknown

Unknown: Claude Opus 4.5 leads 4–0 across 4 shared unknown benchmarks (largest gap: ProofBench, 36 vs 19 — single evaluator).

4 reproduced4 unverified

Agentic

Agentic: Claude Opus 4.5 leads 3–0 across 3 shared agentic benchmarks (largest gap: Cybench, 82 vs 60 — single evaluator).

2 self-reported4 unverified

Math

Math: Claude Opus 4.5 leads 2–0 across 2 shared math benchmarks (largest gap: OTIS Mock AIME 2024-2025, 86.1 vs 77.76 — single evaluator).

4 reproduced

A higher score does not always mean a better model. Each number is task performance under a disclosed harness. Of the 48 measurements across 24 shared benchmarks, 48 single-evaluator or undisclosed-protocol reports; 38% are independently reproduced. Claude Sonnet 4.5 pricing is cross-check disputed — weigh cost claims with the same caution as benchmark wins. Check any benchmark's integrity grade before reading a win as decisive.

Frequently asked questions

Claude Opus 4.5 leads 23–0 across 24 shared benchmarks. Claude Opus 4.5 leads 23 benchmarks and Claude Sonnet 4.5 leads 0, with 1 tied. Higher isn't always better — see the integrity caveats on each benchmark.

Claude Opus 4.5 and Claude Sonnet 4.5 have 24 benchmarks in common in our data — those are the only rows where a direct, apples-to-apples comparison is drawn.

Claude Opus 4.5 leads reasoning 5–0. Claude Opus 4.5 leads unknown 4–0.

Follow the record

These models

Same tier