Gemini 3.5 FlashvsComposer 2.5

Gemini 3.5 Flash
Composer 2.5
Benchmarks
Nonsense detection
BullshitBench v2
20%
Prompt injection robustness
Gray Swan IPI · k = 1
14.1%
Prompt injection robustness
Gray Swan IPI · k = 10
54.2%
Prompt injection robustness
Gray Swan IPI · k = 15
60.5%
Agentic coding
SWE-Bench Pro
55.1%Best
54%
Multilingual coding
SWE-Bench Multilingual
79.8%
Agentic coding
CursorBench v3.2
48.8%
56.1%Best
Agentic coding
CursorBench v3.1
49.8%
63.2%Best
Agentic coding
DeepSWE 1.1
37%
Agentic coding
DeepSWE 1.0
18%
ML engineering
MLE-Bench
49.7%
Next.js coding
Next.js Evals
92%
Agentic terminal coding
Terminal-Bench 2.1
76.2%Best
73%
Agentic terminal coding
Terminal-Bench 2.0
69.3%
Multi-step tool use
MCP Atlas
83.6%
General tool use
Toolathlon
56.5%
Browser agent
BU Bench
58%
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
Knowledge work
GDPval-AA v2
1349
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%
Community preference
Arena Elo (Text)
1476
Community preference (code)
Arena Elo (Code)
1499
Overview
CompanyGoogleSpaceXAI
Release dateMay 19 2026May 18 2026
AccessProprietaryProprietary

Which is better: Gemini 3.5 Flash or Composer 2.5?

Gemini 3.5 Flash and Composer 2.5 are evenly matched across the 4 benchmarks they both report (SWE-Bench Pro, CursorBench v3.2, CursorBench v3.1, Terminal-Bench 2.1). Composer 2.5 shipped 1 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 SWE-Bench Pro, Gemini 3.5 Flash leads at 55.1% vs Composer 2.5 at 54%. On CursorBench v3.2, Composer 2.5 leads at 56.1% vs Gemini 3.5 Flash at 48.8%. On CursorBench v3.1, Composer 2.5 leads at 63.2% vs Gemini 3.5 Flash at 49.8%. On Terminal-Bench 2.1, Gemini 3.5 Flash leads at 76.2% vs Composer 2.5 at 73%.

Frequently asked questions

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

Composer 2.5 was released by SpaceXAI on May 18 2026.

Gemini 3.5 Flash leads on SWE-Bench Pro — Gemini 3.5 Flash 55.1% vs Composer 2.5 54%.

Other comparisons