LLMdeepseek

DeepSeek: DeepSeek V3.1

DeepSeek-V3.1 is a large hybrid reasoning model (671B parameters, 37B active) that supports both thinking and non-thinking modes via prompt templates. It extends the DeepSeek-V3 base with a two-phase long-context...

Anyone in the Project can @-mention DeepSeek: DeepSeek V3.1 with the team's shared context - pooled credits, one chat, one memory.

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Verdict

DeepSeek V3.1 delivers strong reasoning and coding performance at a fraction of typical frontier model costs — $0.25 input makes it one of the cheapest capable models available. The 163K context window handles substantial documents comfortably. Trade-off: it lacks vision capabilities and multimodal support that competitors offer at similar price points. Reach for this when you need cost-efficient text reasoning, coding assistance, or long-document work without image analysis requirements.

Best for

  • Cost-sensitive coding and debugging tasks
  • Long-context document analysis under budget
  • High-volume text reasoning workloads
  • Prototyping before scaling to pricier models

Strengths

The pricing structure makes DeepSeek V3.1 exceptionally economical for text-heavy workflows — input costs run 4-10× cheaper than Claude or GPT-4 class models. The 163K context window provides ample room for multi-file codebases, lengthy research papers, or conversation histories without truncation. DeepSeek's architecture prioritizes reasoning tasks and structured output generation, making it reliable for analytical work that doesn't require cutting-edge creative writing or multimodal understanding.

Trade-offs

DeepSeek V3.1 is text-only, so any workflow involving images, PDFs with visual elements, or screenshots requires a different model. While competitive on reasoning benchmarks, it trails GPT-4o and Claude Sonnet 4.5 on nuanced creative writing and complex instruction-following in our testing. The output pricing at $0.95/Mtok climbs quickly for generation-heavy tasks like drafting long documents. Limited public benchmark data makes it harder to predict performance on specialized domains compared to heavily-tested alternatives.

Specifications

Provider
deepseek
Category
llm
Context length
163,840 tokens
Max output
32,768 tokens
Modalities
text
License
proprietary
Released
2025-08-21

Pricing

Input
$0.25/Mtok
Output
$0.95/Mtok
Model ID
deepseek/deepseek-chat-v3.1

Per-token prices show what the model costs upstream. On Switchy your team draws from one shared org credit pool - one plan, one balance for everyone.

Team cost calculator

Estimated monthly spend
$8.10
17.6M tokens / month
5 seats · 80 msgs/day

Switchy meters this against your org's shared credit pool - one plan, one balance for everyone.

Providers

ProviderContextInputOutputP50 latencyThroughput30d uptime
deepseek164k$0.25/Mtok$0.95/Mtok———

Performance

Performance snapshots are collected daily. Check back after the next ingestion run.

Benchmarks

Public benchmark scores are not available yet for this model. Check back after the next ingestion run.

Works well with

Top MCPs

Compatibility data comes from first-party telemetry; once we have enough co-usage signal, top MCPs for this model will appear here.

How Switchy teams use it

Not enough Projects have used this model yet to share anonymised team stats. We wait for at least 50 distinct Projects per week before publishing any aggregate.

Starter prompts

Debug Python Function

Review this Python function for bugs and edge cases. Explain any issues you find and provide a corrected version with inline comments explaining the fixes.

Summarize Research Paper

Read this research paper and provide a structured summary: research question, methodology, key findings, and limitations. Focus on technical accuracy over brevity.

Generate SQL Query

Given this database schema and requirements, write an optimized SQL query. Explain your indexing assumptions and any performance considerations.

Compare Technical Approaches

Compare these two technical approaches for solving [problem]. List concrete pros and cons for each, then recommend one with specific reasoning based on the constraints I've described.

Extract Structured Data

Extract all mentioned dates, entities, and key events from this text into a JSON structure. Use ISO 8601 for dates and include confidence scores if any information is ambiguous.

Example outputs

Illustrative - representative of the model's voice and quality, not literal recordings.

Prompt

Refactor this Python function to use list comprehensions and remove the nested loops. Keep the same logic but make it more Pythonic.

Output

The model would produce a clean refactor that replaces nested for-loops with a single list comprehension, preserving edge cases like empty inputs. It typically adds inline comments explaining the transformation and suggests further optimizations (e.g., using `itertools` for large datasets). The code follows PEP 8 conventions and includes a brief explanation of why the refactor improves readability and performance.

Notes

DeepSeek V3.1 excels at code transformations that balance clarity with efficiency. With a 163K token context window, it can handle entire module refactors without losing track of dependencies. The output tends toward conservative changes—it won't rewrite your architecture unless you explicitly ask—which makes it safer for production codebases but sometimes misses bolder simplifications.

Prompt

Explain the Byzantine Generals Problem and how it relates to blockchain consensus. Assume I understand distributed systems but haven't studied cryptography.

Output

The model would deliver a structured explanation starting with the core problem (coordinating agreement among parties when some may be faulty), then bridge to blockchain by showing how proof-of-work and proof-of-stake solve the same trust issue without a central authority. It uses analogies (e.g., comparing miners to generals sending signed messages) and avoids jargon overload. The response includes a brief note on trade-offs like energy cost in PoW versus stake centralization in PoS.

Notes

This example highlights DeepSeek V3.1's ability to calibrate explanations to stated knowledge levels. It doesn't assume you need a CS101 primer, but it also doesn't skip the conceptual bridge from theory to application. At $0.25/$0.95 per million tokens, the pricing makes it viable for long-form technical writing where you need multiple drafts. The model occasionally front-loads definitions when a direct answer would suffice.

Prompt

Draft a 200-word product announcement for a SaaS analytics dashboard launching next month. Tone: confident but not hype-driven. Audience: engineering managers.

Output

The model would produce a concise announcement that leads with the problem (fragmented metrics across tools), introduces the solution (unified dashboard with custom SQL queries), and closes with availability details. The tone stays grounded—no 'game-changing' or 'revolutionary' language—and includes a specific feature callout (e.g., 'sub-second query response on 10M+ events'). It structures the copy with short paragraphs and a clear call-to-action, matching the no-nonsense style engineering managers expect.

Notes

DeepSeek V3.1 handles constrained creative tasks well when you specify tone and audience upfront. The 163K context window is overkill here, but it means you could paste your entire brand guidelines and past announcements for style consistency. The model sometimes underuses persuasive techniques—this draft would be clear and credible, but might lack the subtle urgency that converts readers into early adopters.

Use-case deep-dives

Multi-document contract synthesis

Why DeepSeek V3.1 handles 40-page RFP responses without breaking stride

A 4-person consultancy needs to pull clauses from 15 client contracts, compare liability terms, and draft a unified response—all in one session. DeepSeek V3.1's 163k token context window fits roughly 120,000 words, meaning you load every contract once and ask follow-up questions without re-uploading. At $0.25 per million input tokens, scanning 100k tokens costs $0.025—negligible even if you iterate 20 times in a day. The output rate of $0.95/Mtok keeps generation cheap for the 3,000-word synthesis you're drafting. If your contracts rarely exceed 30 pages combined, a smaller context model saves you nothing here; DeepSeek's window is the unlock. For teams running 5+ RFP cycles a month, this model pays for itself in the second week by eliminating manual copy-paste and context-loss errors.

Overnight batch content moderation

DeepSeek V3.1 for high-volume comment filtering on a tight budget

A 10-person community platform reviews 50,000 user comments daily, flagging policy violations before morning. DeepSeek V3.1 processes text at $0.25/Mtok input, so 50k comments averaging 100 tokens each (5M tokens total) cost $1.25 in input fees. Output is minimal—binary flags plus short explanations—so the $0.95/Mtok rate adds maybe $0.50. Total nightly spend: under $2 for a workload that would take a human moderator 40 hours. The 163k context window is overkill here, but the pricing floor makes it viable. If you're under 10k comments/day, the setup overhead outweighs the savings; above 30k, DeepSeek becomes the obvious call. For platforms scaling past seed stage, this model turns moderation from a hiring bottleneck into a line-item expense.

Iterative technical documentation drafting

Why DeepSeek V3.1 fits API reference generation for lean dev teams

A 3-engineer SaaS team ships a new API every quarter and needs reference docs that match the codebase exactly. DeepSeek V3.1's context window holds 50+ endpoint definitions, request/response examples, and error tables in a single prompt, so the model cross-references parameter names and catches inconsistencies a human would miss. At $0.25 input and $0.95 output per Mtok, generating 20,000 words of structured docs costs roughly $0.20—cheap enough to regenerate on every commit if you automate it. The trade-off: if your API surface is under 10 endpoints, a smaller model with tighter instruction-following might produce cleaner Markdown faster. Above 20 endpoints, DeepSeek's ability to reason across the full spec without hallucinating deprecated fields makes it the right pick. For teams without a dedicated tech writer, this model ships docs that don't embarrass you.

Frequently asked

Is DeepSeek V3.1 good for long document analysis?

Yes. The 163,840-token context window handles most books, legal documents, and codebases in a single pass. At $0.25/Mtok input, you can process a 100k-token document for about 2.5 cents. That's cheaper than splitting it across multiple calls to shorter-context models, and you avoid the coherence loss from chunking.

Is DeepSeek V3.1 cheaper than GPT-4o or Claude Sonnet?

Significantly cheaper on input, mixed on output. Input costs $0.25/Mtok versus GPT-4o's $2.50 and Sonnet 3.5's $3.00 — a 10-12x advantage. Output at $0.95/Mtok undercuts GPT-4o ($10) but trails Sonnet ($15). For read-heavy tasks like summarization or analysis, DeepSeek wins decisively. For generation-heavy work, the gap narrows but it's still cheaper overall.

Can DeepSeek V3.1 handle structured JSON output reliably?

Generally yes, though we lack public benchmark data to quantify it. Most modern LLMs at this tier handle JSON schemas well when prompted correctly. Test it on your specific schema first — the low input cost makes experimentation cheap. If you need guaranteed structure, pair it with a validation layer or consider models with formal JSON mode.

How does DeepSeek V3.1 compare to V3?

We don't have benchmark deltas yet, but version increments typically bring quality improvements and bug fixes rather than architectural changes. The pricing and context window match V3, so treat this as a refinement. If V3 worked for your use case, V3.1 should be a safe upgrade. Monitor your evals if quality is mission-critical.

Should I use DeepSeek V3.1 for production chatbots?

Depends on your latency and quality bars. The pricing makes it attractive for high-volume chat, and the large context window supports multi-turn conversations without truncation. But without public benchmarks, you're flying blind on response quality versus GPT-4o or Claude. Run A/B tests with real users before committing production traffic.

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Data last verified 13 hours ago.Sources aggregated hourly to weekly. See docs/architecture/model-directory.md.