Claude Sonnet 4.5 vs GPT-5.2

Claude Sonnet 4.5 (2025) and GPT-5.2 (2025) are frontier-tier reasoning models from Anthropic and OpenAI. Claude Sonnet 4.5 ships a 200k-token context window, while GPT-5.2 ships a 400k-token context window. On SWE-bench Verified, GPT-5.2 leads by 2.8 pts. On pricing, Claude Sonnet 4.5 ranges from $3 to $6/1M input tokens by tier; GPT-5.2 costs $1.75/1M input tokens. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.

GPT-5.2 is safer overall; choose Claude Sonnet 4.5 when vision-heavy evaluation matters.

Decision scorecard

Local evidence first
SignalClaude Sonnet 4.5GPT-5.2
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 window200k400k
Cheapest output$15/1M tokens$14/1M tokens
Provider routes8 tracked4 tracked
Shared benchmarks2 sharedSWE-bench Verified leader

Decision tradeoffs

Choose Claude Sonnet 4.5 when...
  • Claude Sonnet 4.5 has broader tracked provider coverage for fallback and route flexibility.
  • Local decision data tags Claude Sonnet 4.5 for Coding, RAG, and Agents.
Choose GPT-5.2 when...
  • GPT-5.2 holds a shared-benchmark lead on SWE-bench Verified, ahead by 2.8 points.
  • GPT-5.2 has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • GPT-5.2 has the lower cheapest tracked output price at $14/1M tokens.
  • GPT-5.2 uniquely exposes Code execution in local model data.
  • Local decision data tags GPT-5.2 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 GPT-5.2

Claude Sonnet 4.5

$6,150

Cheapest tracked route/tier: Microsoft Foundry

GPT-5.2

$4,900

Cheapest tracked route/tier: Replicate API

Estimated monthly gap: $1,250. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Claude Sonnet 4.5 -> GPT-5.2
  • Provider overlap exists on Replicate API, OpenRouter, and Vercel AI Gateway; start route-level A/B tests there.
  • GPT-5.2 is $1/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • GPT-5.2 adds Code execution in local capability data.
GPT-5.2 -> Claude Sonnet 4.5
  • Provider overlap exists on Replicate API, OpenRouter, and Vercel AI Gateway; start route-level A/B tests there.
  • Claude Sonnet 4.5 is $1/1M 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.

Specs

Specification
Released2025-09-292025-12-11
Context window200k400k
Parameters——
ArchitectureDecoder OnlyDecoder Only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
WeightsNot releasedNot released
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: conditional
Knowledge cutoff2025-122025-08

Pricing and availability

Pricing attributeClaude Sonnet 4.5GPT-5.2
Input price
0-200,001t
$3/1M tokens
200,001t+
$6/1M tokens
$1.75/1M tokens
Output price
0-200,001t
$15/1M tokens
200,001t+
$22.50/1M tokens
$14/1M tokens
Providers
Microsoft FoundryAnthropicSnowflake CortexGCP Vertex AIAWS BedrockReplicate API
Replicate APIOpenRouterVercel AI GatewayOpenAI API

Capabilities

CapabilityClaude Sonnet 4.5GPT-5.2
VisionYesYes
MultimodalYesYes
ReasoningYesYes
JSON / Tool useYesYes
Structured outputsYesYes
Code executionNoYes
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkClaude Sonnet 4.5GPT-5.2
SWE-bench Verified77.280.0
MMMU Pro68.979.5

Continue comparing

Model pages
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Last reviewed: 2026-10-07. Data sourced from public model cards and provider documentation.