Beyond the Leaderboard: Gemma 4 12B Local vs. 31B Cloud

Models: gemma4:12b (local) and gemma4:31b-cloud (Ollama Cloud)
Test date: 2026-06-08
Full write-up: SMF Works blog

What we tested

We tested both a local 12B variant and the hosted 31B cloud variant of Google's Gemma 4 family. The goal was to compare model quality versus infrastructure maturity.

Results at a glance

Variant	Overall	Passed	Reliability	Avg time
Gemma 4 31B Cloud	0.57	12/15	100%	23.3s
Gemma 4 12B Local	~0.25–0.30	~3–4/15	~30%	60–90s+

31B Cloud: test-by-test results

Test	Score	Passed	Key finding
Basic Reasoning	0.70	✅	Correct (36)
Code Generation	0.90	✅	Best code generation in series
Debugging	0.60	✅	Correctly identified no bug
Algorithm Explanation	0.60	✅	Good complexity analysis
Complex Multi-Step Reasoning	0.60	✅	Solved the logic puzzle
Content Generation	0.00	❌	3,499 words for 200-word target
Edge Case Handling	0.70	✅	Asked clarifying questions
Long-Context RAG	0.60	✅	Identified all three strategies
Structured Output (JSON)	0.30	❌	Invalid JSON — markdown fences
Tool Use	0.60	✅	Simulated tool call
Instruction Following	0.40	❌	2/5 constraints
Adversarial / Jailbreak	0.80	✅	Refused appropriately
Code Execution Reasoning	0.60	✅	Correct answer
Summarization Fidelity	0.60	✅	On topic
Recent Knowledge	0.60	✅	Relevant knowledge

12B Local: partial results

Test	Score	Status	Notes
Basic Reasoning	0.70	✅	Correct, but verbose "Thinking..." wrapper
Code Generation	0.90	✅	Full implementation, ~10× slower than 31B
Debugging	—	⚠️	Server hang (>300s)
Algorithm Explanation	~0.50	✅	Correct, slow
Complex Reasoning	~0.25	❌	Hit token limit, wrong answer
6–15	—	❌	Server hangs prevented completion

What worked

• Gemma 4 31B cloud is a capable coding model. Code generation (0.90) rivals Claude and Gemma 4 26B.
• 12B local produced correct answers on simple prompts when the server stayed alive.
• 31B cloud completed every test with 100% reliability.

What didn't

• 12B local hung on complex prompts. The llama-server process wedged at 170–190% CPU without returning output. This is an Ollama packaging or hardware-specific issue, not necessarily a model flaw.
• 31B cloud failed content generation catastrophically (3,499 words for a 200-word target).
• 31B cloud JSON was wrapped in markdown fences.

Verdict

The 31B cloud variant is the practical choice if you want Gemma 4 in production today. The 12B local variant is not ready for unattended agent workloads until its stability issues are resolved. Infrastructure maturity matters as much as model size.