Compare · ModelsLive · 2 picked · head to head
Claude Sonnet 4.5 vs gpt-oss-120b
Side by side · benchmarks, pricing, and signals you can act on.
Winner summary
Claude Sonnet 4.5 wins on 5/8 benchmarks
Claude Sonnet 4.5 wins 5 of 8 shared benchmarks. Leads in knowledge · reasoning · coding.
Category leads
knowledge·Claude Sonnet 4.5math·gpt-oss-120breasoning·Claude Sonnet 4.5coding·Claude Sonnet 4.5
Hype vs Reality
Attention vs performance
Claude Sonnet 4.5
#130 by perf·no signal
gpt-oss-120b
#106 by perf·no signal
Best value
gpt-oss-120b
87.6x better value than Claude Sonnet 4.5
Claude Sonnet 4.5
4.7 pts/$
$9.00/M
gpt-oss-120b
409.6 pts/$
$0.11/M
Vendor risk
Who is behind the model
Anthropic
$380.0B·Tier 1
OpenAI
$840.0B·Tier 1
Head to head
8 benchmarks · 2 models
Claude Sonnet 4.5gpt-oss-120b
Chess Puzzles
gpt-oss-120b leads by +8.0
Chess Puzzles · tests strategic and tactical reasoning by having models solve chess puzzle positions, evaluating lookahead and pattern recognition abilities.
Claude Sonnet 4.5
12.0
gpt-oss-120b
20.0
GPQA diamond
Claude Sonnet 4.5 leads by +8.8
Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs.
Claude Sonnet 4.5
76.4
gpt-oss-120b
67.7
OTIS Mock AIME 2024-2025
gpt-oss-120b leads by +11.1
OTIS Mock AIME 2024–2025 · simulated American Invitational Mathematics Examination problems testing advanced problem-solving skills.
Claude Sonnet 4.5
77.8
gpt-oss-120b
88.9
SimpleBench
Claude Sonnet 4.5 leads by +38.6
SimpleBench · tests fundamental reasoning capabilities with straightforward problems designed to expose gaps in basic logical and spatial thinking.
Claude Sonnet 4.5
45.2
gpt-oss-120b
6.5
SimpleQA Verified
Claude Sonnet 4.5 leads by +9.7
SimpleQA Verified · short factual questions with verified answers, measuring factual accuracy and the tendency to hallucinate or provide incorrect information.
Claude Sonnet 4.5
23.6
gpt-oss-120b
13.9
SWE-Bench Verified (Bash Only)
Claude Sonnet 4.5 leads by +44.6
SWE-Bench Verified (Bash Only) · a curated subset of SWE-bench where models fix real Python repository bugs using only bash commands, no agent frameworks.
Claude Sonnet 4.5
70.6
gpt-oss-120b
26.0
Terminal Bench
Claude Sonnet 4.5 leads by +27.8
Terminal Bench · tests the ability to accomplish real-world tasks using terminal commands, evaluating shell scripting and CLI tool proficiency.
Claude Sonnet 4.5
46.5
gpt-oss-120b
18.7
WeirdML
gpt-oss-120b leads by +0.5
WeirdML · tests models on unusual and adversarial machine learning tasks that require creative problem-solving beyond standard patterns.
Claude Sonnet 4.5
47.7
gpt-oss-120b
48.2
Full benchmark table
| Benchmark | Claude Sonnet 4.5 | gpt-oss-120b |
|---|---|---|
Chess Puzzles Chess Puzzles · tests strategic and tactical reasoning by having models solve chess puzzle positions, evaluating lookahead and pattern recognition abilities. | 12.0 | 20.0 |
GPQA diamond Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs. | 76.4 | 67.7 |
OTIS Mock AIME 2024-2025 OTIS Mock AIME 2024–2025 · simulated American Invitational Mathematics Examination problems testing advanced problem-solving skills. | 77.8 | 88.9 |
SimpleBench SimpleBench · tests fundamental reasoning capabilities with straightforward problems designed to expose gaps in basic logical and spatial thinking. | 45.2 | 6.5 |
SimpleQA Verified SimpleQA Verified · short factual questions with verified answers, measuring factual accuracy and the tendency to hallucinate or provide incorrect information. | 23.6 | 13.9 |
SWE-Bench Verified (Bash Only) SWE-Bench Verified (Bash Only) · a curated subset of SWE-bench where models fix real Python repository bugs using only bash commands, no agent frameworks. | 70.6 | 26.0 |
Terminal Bench Terminal Bench · tests the ability to accomplish real-world tasks using terminal commands, evaluating shell scripting and CLI tool proficiency. | 46.5 | 18.7 |
WeirdML WeirdML · tests models on unusual and adversarial machine learning tasks that require creative problem-solving beyond standard patterns. | 47.7 | 48.2 |
Pricing · per 1M tokens · projected $/mo at 10M tokens
| Model | Input | Output | Context | Projected $/mo |
|---|---|---|---|---|
| Claude Sonnet 4.5 | $3.00 | $15.00 | 1.0M tokens (~500 books) | $60.00 |
| gpt-oss-120b | $0.04 | $0.19 | 131K tokens (~66 books) | $0.77 |