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Model comparison

Claude Sonnet 4.5 vs o1

Data verified

Head-to-head evidence from 2 shared benchmark results across 2 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

52.89/100
Margin
5.8pts
← winning
OpenAI
47.14/100
2 category wins0 category wins

Public leaderboard positions: Claude Sonnet 4.5 #98 (Estimated); o1 #136 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Sonnet 4.5 and o1 share 2 comparable benchmark results. 2 of 8 categories are comparable. 10 results are unique to Claude Sonnet 4.5; 14 to o1.

Updated July 24, 2026
Shared results
2
Claude Sonnet 4.5 only
10
o1 only
14
Comparable categories
2 / 8

Pick Claude Sonnet 4.5 if you want the stronger benchmark profile. o1 only becomes the better choice if you want the stronger reasoning-first profile.

Confidence note. This is a partial-evidence comparison with 2 shared benchmark results across 2 evidence categories; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Claude Sonnet 4.5 is clearly ahead on the BenchAlign aggregate, 52.89 to 47.14. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Sonnet 4.5's sharpest advantage is in knowledge, where it averages 83.4 against 75.7. The single biggest benchmark swing on the page is GPQA, 83.4% to 75.7%.

o1 is also the more expensive model on tokens at $15.00 input / $60.00 output per 1M tokens, versus $3.00 input / $15.00 output per 1M tokens for Claude Sonnet 4.5. That is roughly 4.0x on output cost alone. o1 is the reasoning model in the pair, while Claude Sonnet 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.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for Claude Sonnet 4.5 and o1
CategoryClaude Sonnet 4.5Δo1
KnowledgeClaude Sonnet 4.583.4Margin 7.7o175.7
MathClaude Sonnet 4.511.2Margin 1.9o19.3
AgenticClaude Sonnet 4.555.4MarginNo overlapo1Not measured
CodingClaude Sonnet 4.577.2MarginNo overlapo1Not measured
ReasoningClaude Sonnet 4.513.6MarginNo overlapo1Not measured
Inst. FollowingClaude Sonnet 4.5Not measuredMarginNo overlapo192.2

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Claude Sonnet 4.5B · o1
  1. GPQA

    Knowledge
    Source ↗
    A 83.4%B 75.7%
    Winner: Claude Sonnet 4.5Δ 7.7
    GPQA: Claude Sonnet 4.5 scored 83.4%; o1 scored 75.7%. Claude Sonnet 4.5 wins this benchmark.
  2. FrontierMath v2 (Tiers 1-3)

    Math
    Source ↗
    A 13.495%B 9.310%
    Winner: Claude Sonnet 4.5Δ 4.2
    FrontierMath v2 (Tiers 1-3): Claude Sonnet 4.5 scored 13.495%; o1 scored 9.310%. Claude Sonnet 4.5 wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricClaude Sonnet 4.5o1Comparison
Input / output priceUSD per 1M tokensClaude Sonnet 4.5$3 input / $15 outputo1$15 input / $60 outputClaude Sonnet 4.5 has the lower combined listed price.
Generation speedtokens per secondClaude Sonnet 4.5Not availableo198 tok/sA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Sonnet 4.5Not availableo132.29 sA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Sonnet 4.5200Ko1200KListed context windows are equal.

Benchmark Deep Dive

Agentic
BenchmarkClaude Sonnet 4.5o1Result
Terminal-Bench 2.0Source 50%Not comparable
OSWorld-VerifiedSource 61.4%Not comparable
VITA-BenchSource 17.0%Not comparable
Gert LabsSource 48.51%Not comparable
JobBenchSource 27.7%Not comparable
τ²-bench resultsSource 62.6%Not comparable
Coding
BenchmarkClaude Sonnet 4.5o1Result
SWE-bench VerifiedSource 77.2%Not comparable
AA Coding IndexSource 39.7%Not comparable
AA-SciCodeSource 35.8%Not comparable
Reasoning
BenchmarkClaude Sonnet 4.5o1Result
ARC-AGI-2Source 13.6%Not comparable
AA-LCRSource 59.3%Not comparable
CritPtSource 0.3%Not comparable
KnowledgeClaude Sonnet 4.5 wins
BenchmarkClaude Sonnet 4.5o1Result
GPQASource 83.4%75.7%Claude Sonnet 4.5 leads
MMLUSource 91.8%Not comparable
Artificial Analysis Intelligence IndexSource 23.4%Not comparable
AA-GPQA DiamondSource 74.7%Not comparable
AA-HLESource 7.7%Not comparable
AA-Omniscience IndexSource -10.5%Not comparable
AA-Omniscience AccuracySource 34.7%Not comparable
AA-Omniscience Hallucination RateSource 69.3%Not comparable
MathClaude Sonnet 4.5 wins
BenchmarkClaude Sonnet 4.5o1Result
AIME 2025Source 87%Not comparable
FrontierMath v2 (Tiers 1-3)Source 13.495%9.310%Claude Sonnet 4.5 leads
FrontierMath v2 (Tier 4)Source 4.167%Not comparable
Multimodal
BenchmarkClaude Sonnet 4.5o1Result
Design Arena WebsiteSource 1219Not comparable
Inst. Following
BenchmarkClaude Sonnet 4.5o1Result
IFEvalSource 92.2%Not comparable
AA-IFBenchSource 70.3%Not comparable
Frequently Asked Questions (3)

Which is better, Claude Sonnet 4.5 or o1?

Claude Sonnet 4.5 is ahead on BenchLM's BenchAlign leaderboard, 52.89 to 47.14. The biggest single separator in this matchup is GPQA, where the scores are 83.4% and 75.7%.

Which is better for knowledge tasks, Claude Sonnet 4.5 or o1?

Claude Sonnet 4.5 has the edge for knowledge tasks in this comparison, averaging 83.4 versus 75.7. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for math, Claude Sonnet 4.5 or o1?

Claude Sonnet 4.5 has the edge for math in this comparison, averaging 11.2 versus 9.3. Inside this category, FrontierMath v2 (Tiers 1-3) is the benchmark that creates the most daylight between them.

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Last updated: July 24, 2026