DeepSeek V3.1 vs GPT-4o-mini

Overview: across our 12-test suite DeepSeek V3.1 wins 7 benchmarks, GPT-4o-mini wins 3, and 2 tests tie. All scores below are from our internal 1–5 tests and ranks refer to the tested model pool.

DeepSeek wins (scores and context):

• Faithfulness: DeepSeek 5 vs GPT-4o-mini 3. In our testing DeepSeek is tied for 1st with 32 others out of 55 (tied for 1st), while GPT-4o-mini ranks 52 of 55. This means DeepSeek is substantially more likely to stick to source material in tasks where hallucination risk matters.
• Structured output: DeepSeek 5 vs GPT-4o-mini 4. DeepSeek is tied for 1st with 24 others of 54 — better for strict JSON/schema adherence.
• Long context: DeepSeek 5 vs GPT-4o-mini 4. DeepSeek is tied for 1st with 36 others of 55, meaning superior retrieval/accuracy at 30K+ token contexts in our tests.
• Persona consistency: DeepSeek 5 vs GPT-4o-mini 4. DeepSeek tied for 1st with 36 others of 53 — better at maintaining character and resisting injection.
• Creative problem solving: DeepSeek 5 vs GPT-4o-mini 2. DeepSeek is tied for 1st (7 others) while GPT-4o-mini ranks 47 of 54; DeepSeek produces more novel, feasible ideas in our creative tasks.
• Strategic analysis: DeepSeek 4 vs GPT-4o-mini 2. DeepSeek ranks 27 of 54 vs GPT's 44 of 54 — stronger at nuanced tradeoff reasoning with numbers.
• Agentic planning: DeepSeek 4 vs GPT-4o-mini 3. DeepSeek ranks 16 of 54 (tied with many) versus GPT at 42 of 54 — better at decomposition and failure recovery.

GPT-4o-mini wins (scores and context):

• Tool calling: GPT-4o-mini 4 vs DeepSeek 3. GPT ranks 18 of 54 (tied) vs DeepSeek 47 of 54 — GPT-4o-mini is safer for accurate function selection, argument formation and sequencing in our tests.
• Classification: GPT-4o-mini 4 vs DeepSeek 3. GPT is tied for 1st with 29 others of 53; choose GPT for routing and categorization tasks.
• Safety calibration: GPT-4o-mini 4 vs DeepSeek 1. GPT ranks 6 of 55 (tied) vs DeepSeek 32 of 55 — GPT-4o-mini better balances refusing harmful requests while permitting legitimate ones in our testing.

Ties:

• Constrained rewriting: both score 3 and rank 31 of 53 (22 models share this score) — similar for tight character-limit compression.
• Multilingual: both score 4 and rank 36 of 55 (tied) — comparable non-English output quality.

External benchmarks (supplementary): GPT-4o-mini scores 52.6% on MATH Level 5 and 6.9% on AIME 2025 (Epoch AI). DeepSeek has no external math scores in the payload. Use these external results as task-specific supplements — they are from Epoch AI, not our internal 1–5 scores.

Practical meaning: pick DeepSeek when you need rigor, schema compliance, long-context retrieval, or creative/problem-solving output. Pick GPT-4o-mini when you prioritize accurate tool invocation, classification, or conservative safety behavior — and you want a lower output token bill.

Pricing per 1,000 tokens: both models charge $0.15 input/mTok; DeepSeek charges $0.75 output/mTok vs GPT-4o-mini $0.60 output/mTok (priceRatio 1.25). For 1M output tokens the output-only cost is $750 (DeepSeek) vs $600 (GPT-4o-mini) — a $150 monthly gap; including equal input volume the totals are $900 vs $750 (diff $150). At 10M output tokens the gap is $1,500/month (DeepSeek $9,000 vs GPT $7,500); at 100M it's $15,000/month (DeepSeek $90,000 vs GPT $75,000). Teams operating at >10M tokens/month should budget the difference; smaller projects may prefer DeepSeek's quality wins despite the 25% higher output cost.

Choose DeepSeek V3.1 if you need highest-fidelity outputs: faithfulness (5 vs 3), structured output (5 vs 4), long-context (5 vs 4), persona consistency (5 vs 4) and creative/problem-solving (5 vs 2) in our tests — ideal for document synthesis, schema-driven APIs, long transcripts and research assistants. Choose GPT-4o-mini if you need better tool-calling (4 vs 3), classification (4 vs 3), and safety calibration (4 vs 1) or want a lower output token cost (0.60 vs 0.75 per mTok); it’s the better pick for function-driven agents, routing, or cost-sensitive production at scale.