Gemma 4 31B vs GPT-5.1

Across our 12-test suite (1–5 scale), Gemma 4 31B wins 3 categories outright, GPT-5.1 wins 1, and 8 are ties in our testing. Structured output: Gemma 5 vs GPT-5.1 4 — Gemma is tied for 1st out of 54 models (tied with 24 others), while GPT ranks 26 of 54. Implication: Gemma is better at JSON/schema strictness and format adherence in real tasks where exact output structure matters. Tool calling: Gemma 5 vs GPT-5.1 4 — Gemma tied for 1st (with 16 others); GPT ranks 18 of 54. That means Gemma selects and sequences functions more accurately in our function/agent tests. Agentic planning: Gemma 5 vs GPT-5.1 4 — Gemma tied for 1st; GPT sits at rank 16. For decomposing goals and recovery strategies, Gemma performed better in our runs. Long-context: GPT-5.1 5 vs Gemma 4 — GPT is tied for 1st for long-context (36 others share this top score) while Gemma ranked 38 of 55. Practically, GPT-5.1 is stronger at retrieval and accuracy when working with 30K+ token documents. Strategic analysis: both score 5 and tie — both handle nuanced tradeoffs well in our tests. Constrained rewriting and creative problem solving: both tie at 4; both are competent but not differentiating. Faithfulness, classification, multilingual, persona consistency and safety calibration: mostly ties (faithfulness 5, classification 4, multilingual 5, persona 5; safety calibration both 2) — expect similar behavior on hallucination resistance, routing accuracy, and non-English outputs in our tests. External benchmarks: GPT-5.1 posts 68% on SWE-bench Verified and 88.6% on AIME 2025 according to Epoch AI (these are third-party scores complementary to our internal suite). Those external results support GPT-5.1's edge on certain coding/math tasks, while Gemma has no external SWE/AIME entries in the payload.

Per the payload, Gemma 4 31B charges $0.13 input + $0.38 output = $0.51 per 1k tokens. GPT-5.1 charges $1.25 input + $10.00 output = $11.25 per 1k tokens. At common volumes that maps to: 1M tokens = $510 (Gemma) vs $11,250 (GPT-5.1); 10M = $5,100 vs $112,500; 100M = $51,000 vs $1,125,000. The ~22x per-mtok gap means Gemma is far cheaper for high-volume applications (chatbots, large-scale API products, content generation). Teams with constrained budgets or high throughput should care; enterprises needing the specific wins of GPT-5.1 may justify the cost for niche, high-value workloads.

Choose Gemma 4 31B if you need low-cost, production-ready AI for strict structured outputs, robust tool/function calling, agentic planning, multimodal inputs, or very high throughput — it costs $0.51/1k tokens (combined) and wins our internal tests for those capabilities. Choose GPT-5.1 if your priority is maximal long-context retrieval or you value its third-party scores (68% SWE-bench, 88.6% AIME per Epoch AI) and you can absorb $11.25/1k tokens; it's the better pick for high-stakes document reasoning and some coding/math workloads despite the much higher price.