LLM Reference

Claude Sonnet 4.5 vs DeepSeek R1

Claude Sonnet 4.5 (2025) and DeepSeek R1 (2025) are frontier-tier reasoning models from Anthropic and DeepSeek. Claude Sonnet 4.5 ships a 200k-token context window, while DeepSeek R1 ships a 128k-token context window. On SWE-bench Verified, Claude Sonnet 4.5 leads by 28 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 R1 when coding workflow support matters.

Decision scorecard

Local evidence first
SignalClaude Sonnet 4.5DeepSeek R1
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsreasoning-heavy apps and provider-routed production
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window200k128k
Cheapest output$15/1M tokens$0.30/1M tokens
Provider routes8 tracked14 tracked
Shared benchmarksSWE-bench Verified leader2 shared

Decision tradeoffs

Choose Claude Sonnet 4.5 when...
  • Claude Sonnet 4.5 holds a shared-benchmark lead on SWE-bench Verified, ahead by 28 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 JSON / Tool use in local model data.
  • Local decision data tags Claude Sonnet 4.5 for Coding, RAG, and Agents.
Choose DeepSeek R1 when...
  • DeepSeek R1 has the lower cheapest tracked output price at $0.30/1M tokens.
  • DeepSeek R1 has broader tracked provider coverage for fallback and route flexibility.
  • DeepSeek R1 uniquely exposes Code execution in local model data.
  • Local decision data tags DeepSeek R1 for Coding, RAG, and Agents.

Monthly cost at traffic

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

Lower estimate DeepSeek R1

Claude Sonnet 4.5

$6,150

Cheapest tracked route/tier: Microsoft Foundry

DeepSeek R1

$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 R1
  • Provider overlap exists on OpenRouter, Microsoft Foundry, and AWS Bedrock; start route-level A/B tests there.
  • DeepSeek R1 is $14.70/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Vision, Multimodal, and JSON / Tool use before moving production traffic.
  • DeepSeek R1 adds Code execution in local capability data.
DeepSeek R1 -> 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.
  • Check replacement coverage for Code execution before moving production traffic.
  • Claude Sonnet 4.5 adds Vision, Multimodal, and JSON / Tool use in local capability data.

Specs

Specification
Released2025-09-292025-01-20
Context window200k128k
Parameters—671B, 37B Active
ArchitectureDecoder OnlyDecoder Only
LicenseProprietaryMITOSI-approved
OpennessProprietaryOpen source
WeightsNot releasedAvailable
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: permitted
Knowledge cutoff2025-122023-12

Pricing and availability

Pricing attributeClaude Sonnet 4.5DeepSeek R1
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
Microsoft FoundryAnthropicSnowflake CortexGCP Vertex AIAWS BedrockReplicate API
DeepSeek PlatformOpenRouterTogether AIFireworks AINVIDIA NIMMicrosoft Foundry

Capabilities

CapabilityClaude Sonnet 4.5DeepSeek R1
VisionYesNo
MultimodalYesNo
ReasoningYesYes
JSON / Tool useYesNo
Structured outputsYesYes
Code executionNoYes
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkClaude Sonnet 4.5DeepSeek R1
SWE-bench Verified77.249.2
Google-Proof Q&A83.471.5

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