Devstral Small 1.1 vs Grok 4.1 Fast

Summary of our 12-test comparison (scores are on our 1–5 scale):

• Grok 4.1 Fast wins 9 tests: persona consistency 5 vs 2, long context 5 vs 4, structured output 5 vs 4, constrained rewriting 4 vs 3, faithfulness 5 vs 4, creative problem solving 4 vs 2, strategic analysis 5 vs 2, agentic planning 4 vs 2, multilingual 5 vs 4. These wins show Grok is markedly stronger for maintaining character and resisting prompt injections (persona consistency), handling 30K+ token retrievals (long context; Grok is tied for 1st of 55 models), and producing faithful, schema-compliant outputs (structured output; Grok tied for 1st of 54). Strategic analysis and creative problem solving scores (5 vs 2 and 4 vs 2) indicate Grok produces more nuanced tradeoff reasoning and feasible ideas in our tests.
• Devstral Small 1.1 wins safety calibration 2 vs 1. Devstral ranks better in safety calibration (rank 12 of 55 vs Grok rank 32 of 55), meaning in our testing it more often makes correct refuse/allow decisions on borderline requests.
• Ties: tool calling (both 4) and classification (both 4). Both models scored 4 on tool calling (rank 18 of 54 for each), so function selection and argument accuracy were comparable in our suite. Both are tied for 1st in classification (many models share that top score), so routing/categorization tasks are equally strong.
• Rankings context: Grok is tied for 1st on long context, persona consistency, structured output, faithfulness and multilingual across the model pool; Devstral sits lower on those axes (e.g., persona consistency rank 51 of 53, long context rank 38 of 55). Practically, choose Grok when you need robust long-document retrieval, multilingual parity, strict JSON/schema outputs, or advanced strategic reasoning; choose Devstral if you prioritize better safety calibration and lower cost.

Devstral Small 1.1 costs $0.10 input + $0.30 output = $0.40 per mTok; Grok 4.1 Fast costs $0.20 input + $0.50 output = $0.70 per mTok. At 1M tokens/month (1,000 mTok) Devstral ≈ $400 vs Grok ≈ $700 (difference $300). At 10M tokens/month Devstral ≈ $4,000 vs Grok ≈ $7,000 (difference $3,000). At 100M tokens/month Devstral ≈ $40,000 vs Grok ≈ $70,000 (difference $30,000). If you run high-volume services (millions of tokens/month) that are cost-sensitive — e.g., consumer chat apps, large-scale classification pipelines — Devstral's lower per-token price matters. If accuracy on long contexts, faithfulness, multilingual output, or agentic planning reduces downstream toil or human review costs, Grok's higher price can be justified for quality-critical workloads.

Choose Devstral Small 1.1 if: you need a lower-cost model ($0.40/mTok combined) for high-volume text-only apps where stricter safety calibration matters (Devstral wins safety calibration and ranks better there). Example: large-scale chat moderation routing or cost-sensitive customer-facing assistants where refusals must be conservative.
Choose Grok 4.1 Fast if: you need the best long-context handling, faithfulness, multilingual quality, persona consistency, and stronger strategic/agentic planning (Grok wins 9 of 12 benchmarks and is tied for 1st on several ranks). Example: multi-file code assistants, deep-research agents, multimodal support, or production systems where reducing hallucinations and handling 30K+ context is worth the extra $0.30/mTok.