Gemma 4 31B vs Grok 4.1 Fast

Across our 12-test suite, Gemma 4 31B wins 3 benchmarks outright, Grok 4.1 Fast wins 1, and 8 are tied.

Where Gemma 4 31B wins:

• Tool calling (5 vs 4): Gemma 4 31B ties for 1st with 16 other models out of 54 tested; Grok 4.1 Fast ranks 18th of 54. For function selection, argument accuracy, and sequencing in agentic workflows, this is a real gap that compounds across multi-step pipelines.
• Agentic planning (5 vs 4): Gemma 4 31B ties for 1st with 14 other models out of 54; Grok 4.1 Fast ranks 16th. Goal decomposition and failure recovery — critical for autonomous agents — favor Gemma 4 31B.
• Safety calibration (2 vs 1): Both models score poorly here relative to the field (p50 is 2), but Gemma 4 31B ranks 12th of 55 vs Grok 4.1 Fast's 32nd of 55. This measures the balance between refusing harmful requests and permitting legitimate ones — Grok 4.1 Fast's score of 1 puts it at the bottom quartile.

Where Grok 4.1 Fast wins:

• Long context (5 vs 4): Grok 4.1 Fast ties for 1st with 36 other models out of 55; Gemma 4 31B ranks 38th of 55. For retrieval accuracy at 30K+ tokens, Grok 4.1 Fast is the better choice — and its 2M context window (vs Gemma 4 31B's 262K) makes this advantage structural, not just benchmark-deep.

Tied benchmarks (8 of 12): Both models score 5/5 on structured output, strategic analysis, multilingual, faithfulness, and persona consistency. Both score 4/4 on constrained rewriting and creative problem solving, and 4/4 on classification. On structured output and strategic analysis, both rank in the tied-for-1st group. These are genuine ties — neither model has a meaningful edge on JSON compliance, multilingual output quality, nuanced tradeoff reasoning, or creative ideation in our testing.

Gemma 4 31B costs $0.13/M input and $0.38/M output. Grok 4.1 Fast costs $0.20/M input and $0.50/M output — 54% more expensive on input and 32% more on output. At 1M output tokens/month, that gap is $120 vs $500 — a $380 difference. At 10M output tokens/month, you're paying $3,800 vs $5,000. At 100M tokens/month, the delta reaches $12,000 annually. For most developers running moderate-to-high volume workloads without extreme context requirements, Gemma 4 31B delivers equivalent or better benchmark performance at meaningfully lower cost. Grok 4.1 Fast's premium is only worth paying if you genuinely need its 2M token context window — which Gemma 4 31B's 262K cannot match — or if you specifically need file input support (listed in Grok 4.1 Fast's modality but not Gemma 4 31B's).

Choose Gemma 4 31B if: you are building agentic pipelines, tool-calling workflows, or multi-step automations — it scores 5 vs 4 on both tool calling and agentic planning in our tests. It also costs less ($0.38/M vs $0.50/M output), making it the default pick for high-volume API usage where context windows under 262K are sufficient. Its multimodal support (text, image, and video input) adds versatility.

Choose Grok 4.1 Fast if: your workload requires processing very long documents, full codebases, or extended conversation histories that exceed 262K tokens — its 2M context window is a hard capability advantage Gemma 4 31B cannot match. It also supports file input as a modality. Accept the higher price ($0.20/M input, $0.50/M output) only when that context window is genuinely necessary. Note that Grok 4.1 Fast uses reasoning tokens (a quirk in the payload), which can affect latency and cost in practice.