LLM Reference

Claude Sonnet 4.5 vs GPT-4 Turbo

Claude Sonnet 4.5 (2025) and GPT-4 Turbo (2024) are frontier reasoning models from Anthropic and OpenAI. Claude Sonnet 4.5 ships a 200k-token context window, while GPT-4 Turbo ships a 128k-token context window. On MMLU PRO, Claude Sonnet 4.5 leads by 16.6 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 GPT-4 Turbo when coding workflow support matters.

Decision scorecard

Local evidence first
SignalClaude Sonnet 4.5GPT-4 Turbo
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsmultimodal apps, tool-calling agents, and provider-routed production
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window200k128k
Cheapest output$15/1M tokens$15/1M tokens
Provider routes8 tracked6 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 16.6 points.
  • Claude Sonnet 4.5 has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Claude Sonnet 4.5 has broader tracked provider coverage for fallback and procurement flexibility.
  • Claude Sonnet 4.5 uniquely exposes Reasoning in local model data.
  • Local decision data tags Claude Sonnet 4.5 for Coding, RAG, and Agents.
Choose GPT-4 Turbo when...
  • GPT-4 Turbo uniquely exposes Code execution in local model data.
  • Local decision data tags GPT-4 Turbo 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 Claude Sonnet 4.5

Claude Sonnet 4.5

$6,150

Cheapest tracked route/tier: Microsoft Foundry

GPT-4 Turbo

$7,750

Cheapest tracked route/tier: Replicate API

Estimated monthly gap: $1,600. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Claude Sonnet 4.5 -> GPT-4 Turbo
  • Provider overlap exists on OpenRouter, Replicate API, and Vercel AI Gateway; start route-level A/B tests there.
  • Cheapest tracked output pricing is tied, so migration risk shifts to quality, latency, and provider packaging.
  • Check replacement coverage for Reasoning before moving production traffic.
  • GPT-4 Turbo adds Code execution in local capability data.
GPT-4 Turbo -> Claude Sonnet 4.5
  • Provider overlap exists on Replicate API, OpenRouter, and Vercel AI Gateway; start route-level A/B tests there.
  • Cheapest tracked output pricing is tied, so migration risk shifts to quality, latency, and provider packaging.
  • Check replacement coverage for Code execution before moving production traffic.
  • Claude Sonnet 4.5 adds Reasoning in local capability data.

Specs

Specification
Released2025-09-292024-04-09
Context window200k128k
Parameters1.76T (8x222B MoE)*
ArchitectureDecoder OnlyMixture of Experts
LicenseProprietaryProprietary
OpennessProprietaryProprietary
Commercial useCommercial use: conditionalCommercial use: conditional
Knowledge cutoff2025-122023-12

Pricing and availability

Pricing attributeClaude Sonnet 4.5GPT-4 Turbo
Input price
0-200,001t
$3/1M tokens
200,001t+
$6/1M tokens
$5/1M tokens
Output price
0-200,001t
$15/1M tokens
200,001t+
$22.50/1M tokens
$15/1M tokens
Providers

Capabilities

CapabilityClaude Sonnet 4.5GPT-4 Turbo
VisionYesYes
MultimodalYesYes
ReasoningYesNo
Function callingYesYes
Tool useYesYes
Structured outputsYesYes
Code executionNoYes
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkClaude Sonnet 4.5GPT-4 Turbo
MMLU PRO86.069.4

Deep dive

On shared benchmark coverage, MMLU PRO has Claude Sonnet 4.5 at 86 and GPT-4 Turbo at 69.4, with Claude Sonnet 4.5 ahead by 16.6 points. The largest visible gap is 16.6 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 reasoning mode: Claude Sonnet 4.5 and code execution: GPT-4 Turbo. Both models share vision, multimodal input, function calling, and tool use, 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 GPT-4 Turbo lists $5/1M input and $15/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Claude Sonnet 4.5 lower by about $1.40 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 6, so concentration risk also matters.

Choose Claude Sonnet 4.5 when reasoning depth, larger context windows, and lower cheapest-tier input-token cost are central to the workload. Choose GPT-4 Turbo when coding workflow support 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 GPT-4 Turbo?

Claude Sonnet 4.5 supports 200k tokens, while GPT-4 Turbo supports 128k 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 GPT-4 Turbo?

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. GPT-4 Turbo lists $5/1M input and $15/1M 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 GPT-4 Turbo open source?

Claude Sonnet 4.5 is listed under Proprietary. GPT-4 Turbo is listed under Proprietary. 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 GPT-4 Turbo?

Both Claude Sonnet 4.5 and GPT-4 Turbo expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.

Which is better for multimodal input, Claude Sonnet 4.5 or GPT-4 Turbo?

Both Claude Sonnet 4.5 and GPT-4 Turbo expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.

Where can I run Claude Sonnet 4.5 and GPT-4 Turbo?

Claude Sonnet 4.5 is available on Microsoft Foundry, Anthropic, Snowflake Cortex, GCP Vertex AI, and AWS Bedrock. GPT-4 Turbo is available on OpenAI API, Azure OpenAI, Salesforce Einstein Generative AI, OpenRouter, and Replicate API. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-06-15. Data sourced from public model cards and provider documentation.