AI Model Release Tracker - Timeline of Major AI Models from 2022-2026

Claude Sonnet 4.5 vs o1

Anthropic
Claude Sonnet 4.5
OpenAI
o1
Overview
CompanyAnthropicOpenAI
Release dateSep 29 2025Dec 5 2024
AccessProprietaryProprietary
Benchmarks
Nonsense detection
BullshitBench v2
79%
Coding
SWE-Bench Verified
77.2%
Next.js coding
Next.js Evals
50%
Science
GPQA Diamond
83.4%
Multimodal
MMMU
68%
Timeline
Release gapo1 shipped 298 days before Claude Sonnet 4.5

Which is better: Claude Sonnet 4.5 or o1?

Claude Sonnet 4.5 and o1 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. o1 shipped 298 days before Claude Sonnet 4.5, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

Direct benchmark comparisons are unavailable — Claude Sonnet 4.5 and o1 don't publish scores on any of the same benchmarks.

Frequently asked questions

Claude Sonnet 4.5 was released by Anthropic on Sep 29 2025.

o1 was released by OpenAI on Dec 5 2024.

Other comparisons