DeepSeek V3.1 vs GPT-4.1 Mini

Head-to-head by test (our 12-test suite):

• DeepSeek V3.1 wins: faithfulness 5 vs 4 (tied for 1st with 32 others out of 55 — excellent for sticking to source material); structured_output 5 vs 4 (tied for 1st with 24 others out of 54 — best choice when strict JSON/schema compliance matters); creative_problem_solving 5 vs 3 (tied for 1st with 7 others out of 54 — better at non-obvious, feasible ideas).
• GPT-4.1 Mini wins: constrained_rewriting 4 vs 3 (rank 6 of 53 — stronger at tight character-limit compression); tool_calling 4 vs 3 (rank 18 of 54 — better function selection and argument accuracy); safety_calibration 2 vs 1 (rank 12 of 55 — calibrates refusals more appropriately); multilingual 5 vs 4 (tied for 1st with 34 others out of 55 — superior non-English quality).
• Ties: strategic_analysis 4/4, classification 3/3, long_context 5/5 (both tied for 1st), persona_consistency 5/5 (both top-tied), agentic_planning 4/4. Context: DeepSeek’s top ranks in faithfulness and structured output mean it’s the safer bet for strict data exports, schema validation, and reliable quoting. GPT-4.1 Mini’s wins in tool calling and constrained rewriting translate to fewer function-misfires and better short-form compression. External math benchmarks for GPT-4.1 Mini are available: MATH Level 5 = 87.3% and AIME 2025 = 44.7% (Epoch AI), which support its strength on higher-difficulty math tasks compared with models lacking these scores. Overall, GPT-4.1 Mini captures more task wins (4 vs 3) while many skills are tied; choose based on the specific capability you need.

DeepSeek V3.1 input/output costs are $0.15/$0.75 per 1k tokens; GPT-4.1 Mini is $0.40/$1.60 per 1k. For output tokens only, 1M tokens cost DeepSeek $750 vs GPT-4.1 Mini $1,600 (difference $850). At 10M output tokens: $7,500 vs $16,000 (diff $8,500). At 100M: $75,000 vs $160,000 (diff $85,000). If you also pay for 1M input tokens the input adds $150 (DeepSeek) vs $400 (GPT-4.1 Mini). High-volume customers (≥10M tokens/month), startups on tight budgets, or apps with predictable, large output volumes should care most about DeepSeek's ~46.9% per-token price advantage (priceRatio 0.46875).

Choose DeepSeek V3.1 if you need low-cost, highly faithful output, strict JSON/schema compliance, long-context reliability, or stronger creative problem solving — e.g., high-volume API deployments that produce structured payloads, long-document summarization that must not hallucinate, or ideation engines where cost matters. Choose GPT-4.1 Mini if you prioritize tool integrations, constrained rewriting (tight character limits), multilingual chatbots, or safer refusal behavior — e.g., apps that call functions, multi-language customer support, or workflows that require better safety calibration and function argument accuracy. If budget is the primary constraint, DeepSeek saves ~$850 per 1M output tokens versus GPT-4.1 Mini.