DeepSeek V3.1 Terminus vs Grok 4

Across our 12-test suite, Grok 4 wins 6 benchmarks, DeepSeek V3.1 Terminus wins 3, and 3 are ties. Here's what that looks like test by test:

Where Grok 4 wins:

• Faithfulness (5 vs 3): Grok 4 ties for 1st of 55 models in our testing; V3.1 Terminus ranks 52nd of 55. This is a significant gap. Faithfulness measures how well a model sticks to source material without hallucinating — critical for summarization, RAG pipelines, and document-grounded Q&A. V3.1 Terminus's score here is a real liability for those workloads.
• Tool Calling (4 vs 3): Grok 4 ranks 18th of 54; V3.1 Terminus ranks 47th of 54. Tool calling covers function selection, argument accuracy, and sequencing — the foundation of agentic and API-integration workflows. A rank-47 score in a field of 54 models is below-median performance.
• Classification (4 vs 3): Grok 4 ties for 1st of 53; V3.1 Terminus ranks 31st. For routing, labeling, and categorization tasks, Grok 4 is measurably stronger.
• Safety Calibration (2 vs 1): Grok 4 ranks 12th of 55; V3.1 Terminus ranks 32nd. Both models are below the field median (p50 = 2), but Grok 4 is meaningfully better at refusing harmful requests while permitting legitimate ones.
• Persona Consistency (5 vs 4): Grok 4 ties for 1st of 53; V3.1 Terminus ranks 38th. This matters for chatbots, character-driven apps, and any system prompt that needs to hold under adversarial input.
• Constrained Rewriting (4 vs 3): Grok 4 ranks 6th of 53; V3.1 Terminus ranks 31st. Compressing content within hard character limits is a common editorial and UX task — Grok 4 handles it more reliably.

Where DeepSeek V3.1 Terminus wins:

• Structured Output (5 vs 4): V3.1 Terminus ties for 1st of 54 in our testing; Grok 4 ranks 26th. JSON schema compliance and format adherence is where V3.1 Terminus has a concrete edge — useful for any system that consumes model output programmatically.
• Creative Problem Solving (4 vs 3): V3.1 Terminus ranks 9th of 54; Grok 4 ranks 30th. Generating non-obvious, specific, feasible ideas is notably stronger in V3.1 Terminus.
• Agentic Planning (4 vs 3): V3.1 Terminus ranks 16th of 54; Grok 4 ranks 42nd. Goal decomposition and failure recovery — V3.1 Terminus outperforms Grok 4 here despite its weaker tool calling score, suggesting it plans better but executes tool calls less reliably.

Ties (both score equally):

• Strategic Analysis (5/5): Both tie for 1st of 54 models in our testing — 26 models share this score.
• Long Context (5/5): Both tie for 1st of 55 — 37 models share this score. Both handle retrieval accuracy at 30K+ tokens equally well.
• Multilingual (5/5): Both tie for 1st of 55 — 35 models share this score.

Modality note: Grok 4 accepts text, image, and file inputs; V3.1 Terminus is text-only. If your workflow involves image or document understanding, Grok 4 is the only option here.

Context window: Grok 4 offers 256,000 tokens vs V3.1 Terminus's 163,840 tokens — relevant for very long document processing.

The price gap here is dramatic. DeepSeek V3.1 Terminus costs $0.21/M input tokens and $0.79/M output tokens. Grok 4 costs $3/M input and $15/M output — roughly 14x more on input and 19x more on output.

At real-world volumes, the difference compounds fast:

• 1M output tokens/month: V3.1 Terminus costs $0.79; Grok 4 costs $15. Difference: $14.21.
• 10M output tokens/month: V3.1 Terminus costs $7.90; Grok 4 costs $150. Difference: $142.10.
• 100M output tokens/month: V3.1 Terminus costs $79; Grok 4 costs $1,500. Difference: $1,421.

Grok 4 also uses reasoning tokens (flagged in its quirks), which means actual output token consumption — and therefore cost — can run higher than a naive estimate.

Who should care about the gap? Any team running batch pipelines, high-volume classification, document processing, or customer-facing chat at scale. At 10M+ output tokens per month, Grok 4 costs roughly $1,400+ more per month for the same token volume. V3.1 Terminus's wins on structured output and agentic planning make it a credible substitute for those specific workflows. Grok 4's premium is most defensible for use cases where faithfulness, tool calling accuracy, or persona stability are critical and errors are expensive — not for general-purpose text generation at volume.

Choose DeepSeek V3.1 Terminus if:

• Cost efficiency is a priority — you're running 10M+ output tokens per month and the $142–$1,400+ monthly savings justify the capability tradeoffs
• Your pipeline depends on structured output: V3.1 Terminus ties for 1st of 54 models in our testing on JSON schema compliance
• You need strong agentic planning (ranks 16th of 54) and creative problem solving (ranks 9th of 54)
• Your workload is text-only and doesn't require image or file input
• You're building document-heavy workflows where strategic analysis is required — both models score equally here at 5/5

Choose Grok 4 if:

• Faithfulness is non-negotiable — Grok 4 ties for 1st of 55 vs V3.1 Terminus's rank 52nd; this is the clearest performance gap in the comparison
• You're building agentic systems that rely on tool calling — Grok 4 ranks 18th of 54 vs V3.1 Terminus's 47th
• Your application requires persona stability (customer-facing chat, roleplay, brand voice) — Grok 4 ties for 1st of 53 vs V3.1 Terminus's 38th
• You need image or file input processing — Grok 4 supports multimodal input; V3.1 Terminus does not
• You need the larger 256K context window for very long document work
• Error cost is high and hallucination risk in RAG or document-grounded tasks is unacceptable at the per-query level