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 rows

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 procurement 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
LicenseProprietaryMIT(OSI)
OpennessProprietaryOpen source
Commercial useCommercial use with conditionsCommercial use allowed
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
Function callingYesYes
Tool useYesYes
Structured outputsYesYes
Code executionNoNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkClaude Sonnet 4.5DeepSeek V3
MMLU PRO86.075.9

Deep dive

On shared benchmark coverage, MMLU PRO has Claude Sonnet 4.5 at 86 and DeepSeek V3 at 75.9, with Claude Sonnet 4.5 ahead by 10.1 points. The largest visible gap is 10.1 points on MMLU PRO, 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 vision: Claude Sonnet 4.5, multimodal input: Claude Sonnet 4.5, and reasoning mode: Claude Sonnet 4.5. Both models share function calling, tool use, and structured outputs, 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 4.5 lists tiered pricing: 0-200,001t is $3/1M input and $15/1M output; 200,001t+ is $6/1M input and $22.50/1M output, while DeepSeek V3 lists $0.10/1M input and $0.30/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts DeepSeek V3 lower by about $6.44 per million blended tokens. For tiered rows, this cheapest-track view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 8 providers versus 13, so concentration risk also matters.

Choose Claude Sonnet 4.5 when reasoning depth and larger context windows are central to the workload. Choose DeepSeek V3 when provider fit, 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 4.5 or DeepSeek V3?

Claude Sonnet 4.5 supports 200k tokens, while DeepSeek V3 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 4.5 or DeepSeek V3?

Claude Sonnet 4.5 lists tiered pricing: 0-200,001t is $3/1M input and $15/1M output; 200,001t+ is $6/1M input and $22.50/1M output. DeepSeek V3 lists $0.10/1M input and $0.30/1M output tokens on the cheapest tracked provider. Compare the tier you will actually use; cheap async pricing can overstate savings for interactive workflows. Provider discounts or batch pricing can still change the final bill.

Is Claude Sonnet 4.5 or DeepSeek V3 open source?

Claude Sonnet 4.5 is listed under Proprietary. DeepSeek V3 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 4.5 or DeepSeek V3?

Claude Sonnet 4.5 has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.

Which is better for multimodal input, Claude Sonnet 4.5 or DeepSeek V3?

Claude Sonnet 4.5 has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.

Where can I run Claude Sonnet 4.5 and DeepSeek V3?

Claude Sonnet 4.5 is available on Microsoft Foundry, Anthropic, Snowflake Cortex, GCP Vertex AI, and AWS Bedrock. DeepSeek V3 is available on DeepInfra, Fireworks AI, DeepSeek Platform, Microsoft Foundry, and OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-05-22. Data sourced from public model cards and provider documentation.