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

Gemini 3.5 Flash vs o3

Google
Gemini 3.5 Flash
OpenAI
o3
Overview
CompanyGoogleOpenAI
Release dateMay 19 2026Apr 16 2025
AccessProprietaryProprietary
Benchmarks
Nonsense detection
BullshitBench v2
20%
26%Best
Agentic coding
SWE-Bench Pro
55.1%
Agentic coding
CursorBench v3.1
49.8%
Agentic terminal coding
Terminal-Bench 2.1
76.2%
Multi-step tool use
MCP Atlas
83.6%
General tool use
Toolathlon
56.5%
Multidisciplinary reasoning
Humanity's Last Exam · no tools
40.2%
Abstract reasoning
ARC-AGI-2
72.1%
Agentic computer use
OSWorld-Verified
78.4%
Agentic financial analysis
Finance Agent v2
57.9%
Knowledge work
GDPval-AA
1656
Chart reasoning
CharXiv Reasoning
84.2%
Multimodal reasoning
MMMU-Pro
83.6%
Spatial reasoning
Blueprint-Bench 2
33.6%
Long context
MRCR v2 (8-needle) · 128k average
77.3%
Long context
MRCR v2 (8-needle) · 1M pointwise
26.6%
Timeline
Release gapo3 shipped 398 days before Gemini 3.5 Flash

Which is better: Gemini 3.5 Flash or o3?

o3 leads Gemini 3.5 Flash on 1 of the 1 benchmark they both report (BullshitBench v2). o3 shipped 398 days before Gemini 3.5 Flash, 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.

On BullshitBench v2, o3 leads at 26% vs Gemini 3.5 Flash at 20%.

Frequently asked questions

Gemini 3.5 Flash was released by Google on May 19 2026.

o3 was released by OpenAI on Apr 16 2025.

Other comparisons