Compare · ModelsLive · 2 picked · head to head

Gemini 3.1 Pro Preview vs Step 3.5 Flash

Side by side · benchmarks, pricing, and signals you can act on.

Winner summary

Gemini 3.1 Pro Preview wins 4 of 4 shared benchmarks. Leads in speed · arena.

Category leads
speed·Gemini 3.1 Pro Previewarena·Gemini 3.1 Pro Preview
Hype vs Reality
Gemini 3.1 Pro Preview
#38 by perf·no signal
QUIET
Step 3.5 Flash
#9 by perf·#11 by attention
DESERVED
Best value
44.4x better value than Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview
8.7 pts/$
$7.00/M
Step 3.5 Flash
384.5 pts/$
$0.20/M
Vendor risk
One or more vendors flagged
Google DeepMind logo
Google DeepMind
$4.00T·Tier 1
Low risk
stepfun logo
StepFun
$5.0B·Tier 1
Higher risk
Head to head
Gemini 3.1 Pro PreviewStep 3.5 Flash
Artificial Analysis · Agentic Index
Gemini 3.1 Pro Preview leads by +7.1
Artificial Analysis Agentic Index · a composite score measuring how well a model performs in agentic workflows · multi-step tool use, planning, error recovery, and autonomous task completion. Aggregates results from multiple agentic benchmarks including SWE-bench, tool-use tests, and planning evaluations. The canonical single-number metric for "how good is this model as an agent?"
Gemini 3.1 Pro Preview
59.1
Step 3.5 Flash
52.0
Artificial Analysis · Coding Index
Gemini 3.1 Pro Preview leads by +23.9
Artificial Analysis Coding Index · a composite score that aggregates performance across multiple coding benchmarks into a single index. Tracks code generation quality, debugging ability, multi-language competence, and real-world software engineering tasks. Used by Artificial Analysis to rank model coding capability in a normalized, comparable format. Useful for developers choosing between models for coding-heavy workloads.
Gemini 3.1 Pro Preview
55.5
Step 3.5 Flash
31.6
Artificial Analysis · Quality Index
Gemini 3.1 Pro Preview leads by +19.4
Gemini 3.1 Pro Preview
57.2
Step 3.5 Flash
37.8
Chatbot Arena Elo · Overall
Gemini 3.1 Pro Preview leads by +101.2
Gemini 3.1 Pro Preview
1492.6
Step 3.5 Flash
1391.4
Full benchmark table
BenchmarkGemini 3.1 Pro PreviewStep 3.5 Flash
Artificial Analysis · Agentic Index
Artificial Analysis Agentic Index · a composite score measuring how well a model performs in agentic workflows · multi-step tool use, planning, error recovery, and autonomous task completion. Aggregates results from multiple agentic benchmarks including SWE-bench, tool-use tests, and planning evaluations. The canonical single-number metric for "how good is this model as an agent?"
59.152.0
Artificial Analysis · Coding Index
Artificial Analysis Coding Index · a composite score that aggregates performance across multiple coding benchmarks into a single index. Tracks code generation quality, debugging ability, multi-language competence, and real-world software engineering tasks. Used by Artificial Analysis to rank model coding capability in a normalized, comparable format. Useful for developers choosing between models for coding-heavy workloads.
55.531.6
Artificial Analysis · Quality Index
57.237.8
Chatbot Arena Elo · Overall
1492.61391.4
Pricing · per 1M tokens · projected $/mo at 10M tokens
ModelInputOutputContextProjected $/mo
Google DeepMind logoGemini 3.1 Pro Preview$2.00$12.001.0M tokens (~524 books)$45.00
stepfun logoStep 3.5 Flash$0.10$0.30262K tokens (~131 books)$1.50