LLM Reference

Claude Sonnet 4.5 vs DeepSeek V3

Claude Sonnet 4.5 (2025) and DeepSeek V3 (2024) are frontier reasoning models from Anthropic and DeepSeek. Claude Sonnet 4.5 ships a 200k-token context window, while DeepSeek V3 ships a 64k-token context window. On MMLU PRO, Claude Sonnet 4.5 leads by 10.1 pts. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.

Claude Sonnet 4.5 is safer overall; choose DeepSeek V3 when provider fit matters.

Decision scorecard

Local evidence first
SignalClaude Sonnet 4.5DeepSeek V3
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentstool-calling agents and provider-routed production
Decision fitCoding, RAG, and AgentsCoding, Agents, and Classification
Context window200k64k
Cheapest output$15/1M tokens$0.30/1M tokens
Provider routes8 tracked13 tracked
Shared benchmarksMMLU PRO leader1 shared

Decision tradeoffs

Choose Claude Sonnet 4.5 when...
  • Claude Sonnet 4.5 holds a shared-benchmark lead on MMLU PRO, ahead by 10.1 points.
  • Claude Sonnet 4.5 has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Claude Sonnet 4.5 uniquely exposes Vision, Multimodal, and Reasoning in local model data.
  • Local decision data tags Claude Sonnet 4.5 for Coding, RAG, and Agents.
Choose DeepSeek V3 when...
  • DeepSeek V3 has the lower cheapest tracked output price at $0.30/1M tokens.
  • DeepSeek V3 has broader tracked provider coverage for fallback and route flexibility.
  • Local decision data tags DeepSeek V3 for Coding, Agents, and Classification.

Monthly cost at traffic

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

Lower estimate DeepSeek V3

Claude Sonnet 4.5

$6,150

Cheapest tracked route/tier: Microsoft Foundry

DeepSeek V3

$155

Cheapest tracked route/tier: Bitdeer AI

Estimated monthly gap: $5,995. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Claude Sonnet 4.5 -> DeepSeek V3
  • Provider overlap exists on Microsoft Foundry, OpenRouter, and AWS Bedrock; start route-level A/B tests there.
  • DeepSeek V3 is $14.70/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Vision, Multimodal, and Reasoning before moving production traffic.
DeepSeek V3 -> Claude Sonnet 4.5
  • Provider overlap exists on Microsoft Foundry, GCP Vertex AI, and AWS Bedrock; start route-level A/B tests there.
  • Claude Sonnet 4.5 is $14.70/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Claude Sonnet 4.5 adds Vision, Multimodal, and Reasoning in local capability data.

Specs

Specification
Released2025-09-292024-12-26
Context window200k64k
Parameters671B
ArchitectureDecoder OnlyMixture of Experts
LicenseProprietaryMITOSI-approved
OpennessProprietaryOpen source
WeightsNot releasedAvailable
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: permitted
Knowledge cutoff2025-122024-04

Pricing and availability

Pricing attributeClaude Sonnet 4.5DeepSeek V3
Input price
0-200,001t
$3/1M tokens
200,001t+
$6/1M tokens
$0.10/1M tokens
Output price
0-200,001t
$15/1M tokens
200,001t+
$22.50/1M tokens
$0.30/1M tokens
Providers

Capabilities

CapabilityClaude Sonnet 4.5DeepSeek V3
VisionYesNo
MultimodalYesNo
ReasoningYesNo
JSON / Tool useYesYes
Structured outputsYesYes
Code executionNoNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkClaude Sonnet 4.5DeepSeek V3
MMLU PRO86.075.9

Continue comparing

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