LLM Reference

Claude Sonnet 4.6 vs o3

Claude Sonnet 4.6 (2026) and o3 (2025) are frontier-tier reasoning models from Anthropic and OpenAI. Claude Sonnet 4.6 ships a 1m-token context window, while o3 ships a 200k-token context window. On SWE-bench Verified, Claude Sonnet 4.6 leads by 7.9 pts. On pricing, o3 costs $2/1M 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.

o3 is ~50% cheaper at $2/1M; pay for Claude Sonnet 4.6 only for coding workflow support.

Decision scorecard

Local evidence first
SignalClaude Sonnet 4.6o3
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsreasoning-heavy apps, multimodal apps, and tool-calling agents
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window1m200k
Cheapest output$15/1M tokens$8/1M tokens
Provider routes6 tracked3 tracked
Shared benchmarksSWE-bench Verified leader9 shared

Decision tradeoffs

Choose Claude Sonnet 4.6 when...
  • Claude Sonnet 4.6 holds a shared-benchmark lead on SWE-bench Verified, ahead by 7.9 points.
  • Claude Sonnet 4.6 has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Claude Sonnet 4.6 has broader tracked provider coverage for fallback and route flexibility.
  • Claude Sonnet 4.6 uniquely exposes Computer use and Parallel agents in local model data.
  • Local decision data tags Claude Sonnet 4.6 for Coding, RAG, and Agents.
Choose o3 when...
  • o3 holds a shared-benchmark lead on LiveCodeBench, ahead by 5.5 points.
  • o3 has the lower cheapest tracked output price at $8/1M tokens.
  • Local decision data tags o3 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 o3

Claude Sonnet 4.6

$6,150

Cheapest tracked route/tier: OpenRouter

o3

$3,600

Cheapest tracked route/tier: OpenAI API

Estimated monthly gap: $2,550. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Claude Sonnet 4.6 -> o3
  • Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
  • o3 is $7/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Computer use and Parallel agents before moving production traffic.
o3 -> Claude Sonnet 4.6
  • Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
  • Claude Sonnet 4.6 is $7/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Claude Sonnet 4.6 adds Computer use and Parallel agents in local capability data.

Specs

Specification
Released2026-02-172025-04-16
Context window1m200k
Parameters——
ArchitectureDecoder OnlyDecoder Only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
WeightsNot releasedNot released
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: conditional
Knowledge cutoff2025-082024-06

Pricing and availability

Pricing attributeClaude Sonnet 4.6o3
Input price$3/1M tokens$2/1M tokens
Output price$15/1M tokens$8/1M tokens
Providers
OpenRouterAnthropicAWS BedrockGCP Vertex AIMicrosoft FoundryVercel AI Gateway
OpenAI APIOpenRouterVercel AI Gateway

Capabilities

CapabilityClaude Sonnet 4.6o3
VisionYesYes
MultimodalYesYes
ReasoningYesYes
JSON / Tool useYesYes
Structured outputsYesYes
Code executionYesYes
IDE integrationNoNo
Computer useYesNo
Parallel agentsYesNo

Benchmarks

BenchmarkClaude Sonnet 4.6o3
SWE-bench Verified79.671.7
Google-Proof Q&A89.987.7
AIME 202594.088.9
LiveCodeBench80.085.5
Massive Multi-discipline Multimodal Understanding83.682.9
Humanity's Last Exam33.220.3
HumanEval98.096.7
Chatbot Arena1459.01412.0
MMMU Pro75.676.4

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