LLM Reference

Claude Sonnet 4.6 vs DeepSeek V3.1

Claude Sonnet 4.6 (2026) and DeepSeek V3.1 (2025) are frontier reasoning models from Anthropic and DeepSeek. Claude Sonnet 4.6 ships a 1m-token context window, while DeepSeek V3.1 ships a 64k-token context window. On MMLU PRO, Claude Sonnet 4.6 leads by 4 pts. On pricing, DeepSeek V3.1 costs $0.27/1M input tokens versus $3/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.

DeepSeek V3.1 is ~1011% cheaper at $0.27/1M; pay for Claude Sonnet 4.6 only for coding workflow support.

Decision scorecard

Local evidence first
SignalClaude Sonnet 4.6DeepSeek V3.1
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsmultimodal apps and provider-routed production
Decision fitCoding, RAG, and AgentsCoding, Agents, and Vision
Context window1m64k
Cheapest output$15/1M tokens$1/1M tokens
Provider routes6 tracked8 tracked
Shared benchmarksMMLU PRO leader2 shared

Decision tradeoffs

Choose Claude Sonnet 4.6 when...
  • Claude Sonnet 4.6 holds a shared-benchmark lead on MMLU PRO, ahead by 4 points.
  • Claude Sonnet 4.6 has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Claude Sonnet 4.6 uniquely exposes Reasoning, Function calling, and Tool use in local model data.
  • Local decision data tags Claude Sonnet 4.6 for Coding, RAG, and Agents.
Choose DeepSeek V3.1 when...
  • DeepSeek V3.1 has the lower cheapest tracked output price at $1/1M tokens.
  • DeepSeek V3.1 has broader tracked provider coverage for fallback and procurement flexibility.
  • Local decision data tags DeepSeek V3.1 for Coding, Agents, and Vision.

Monthly cost at traffic

Estimate token spend from the cheapest tracked input and output route or tier on this page.

Lower estimate DeepSeek V3.1

Claude Sonnet 4.6

$6,150

Cheapest tracked route/tier: OpenRouter

DeepSeek V3.1

$466

Cheapest tracked route/tier: Novita AI

Estimated monthly gap: $5,684. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Claude Sonnet 4.6 -> DeepSeek V3.1
  • Provider overlap exists on Microsoft Foundry, AWS Bedrock, and Vercel AI Gateway; start route-level A/B tests there.
  • DeepSeek V3.1 is $14/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Reasoning, Function calling, and Tool use before moving production traffic.
DeepSeek V3.1 -> Claude Sonnet 4.6
  • Provider overlap exists on AWS Bedrock, Microsoft Foundry, and Vercel AI Gateway; start route-level A/B tests there.
  • Claude Sonnet 4.6 is $14/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Claude Sonnet 4.6 adds Reasoning, Function calling, and Tool use in local capability data.

Specs

Specification
Released2026-02-172025-08-21
Context window1m64k
Parameters671B total, 37B active (MoE)
ArchitectureDecoder OnlyMixture of Experts
LicenseProprietaryMITOSI-approved
OpennessProprietaryOpen source
WeightsNot releasedUnknown
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: permitted
Knowledge cutoff2025-08-

Pricing and availability

Pricing attributeClaude Sonnet 4.6DeepSeek V3.1
Input price$3/1M tokens$0.27/1M tokens
Output price$15/1M tokens$1/1M tokens
Providers

Capabilities

CapabilityClaude Sonnet 4.6DeepSeek V3.1
VisionYesYes
MultimodalYesYes
ReasoningYesNo
Function callingYesNo
Tool useYesNo
Structured outputsYesYes
Code executionYesYes
IDE integrationNoNo
Computer useYesNo
Parallel agentsYesNo

Benchmarks

BenchmarkClaude Sonnet 4.6DeepSeek V3.1
MMLU PRO87.383.3
SWE-bench Verified79.666.0

Deep dive

On shared benchmark coverage, MMLU PRO has Claude Sonnet 4.6 at 87.3 and DeepSeek V3.1 at 83.3, with Claude Sonnet 4.6 ahead by 4 points; SWE-bench Verified has Claude Sonnet 4.6 at 79.6 and DeepSeek V3.1 at 66, with Claude Sonnet 4.6 ahead by 13.6 points. The largest visible gap is 13.6 points on SWE-bench Verified, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.

The capability footprint differs most on reasoning mode: Claude Sonnet 4.6, function calling: Claude Sonnet 4.6, and tool use: Claude Sonnet 4.6. Both models share vision, multimodal input, structured outputs, and code execution, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.

For cost, Claude Sonnet 4.6 lists $3/1M input and $15/1M output tokens on the cheapest tracked provider, while DeepSeek V3.1 lists $0.27/1M input and $1/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts DeepSeek V3.1 lower by about $6.11 per million blended tokens. Availability is 6 providers versus 8, so concentration risk also matters.

Choose Claude Sonnet 4.6 when coding workflow support and larger context windows are central to the workload. Choose DeepSeek V3.1 when coding workflow support, lower input-token cost, and broader provider choice are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.

FAQ

Which has a larger context window, Claude Sonnet 4.6 or DeepSeek V3.1?

Claude Sonnet 4.6 supports 1m tokens, while DeepSeek V3.1 supports 64k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.

Which is cheaper, Claude Sonnet 4.6 or DeepSeek V3.1?

DeepSeek V3.1 is cheaper on tracked token pricing. Claude Sonnet 4.6 costs $3/1M input and $15/1M output tokens. DeepSeek V3.1 costs $0.27/1M input and $1/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is Claude Sonnet 4.6 or DeepSeek V3.1 open source?

Claude Sonnet 4.6 is listed under Proprietary. DeepSeek V3.1 is listed under MIT. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.

Which is better for vision, Claude Sonnet 4.6 or DeepSeek V3.1?

Both Claude Sonnet 4.6 and DeepSeek V3.1 expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.

Which is better for multimodal input, Claude Sonnet 4.6 or DeepSeek V3.1?

Both Claude Sonnet 4.6 and DeepSeek V3.1 expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.

Where can I run Claude Sonnet 4.6 and DeepSeek V3.1?

Claude Sonnet 4.6 is available on OpenRouter, Anthropic, AWS Bedrock, GCP Vertex AI, and Microsoft Foundry. DeepSeek V3.1 is available on Microsoft Foundry, Fireworks AI, NVIDIA NIM, Together AI, and AWS Bedrock. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-07-26. Data sourced from public model cards and provider documentation.