LLM Reference

Claude Sonnet 4.6 vs GPT-5.2 Codex

Claude Sonnet 4.6 (2026) and GPT-5.2 Codex (2025) compare a standalone API model against a coding-specialized model. Claude Sonnet 4.6 ships a 1m-token context window, while GPT-5.2 Codex ships a not-yet-sourced context window. On pricing, GPT-5.2 Codex costs $1.75/1M input tokens versus $3/1M for the alternative. This page treats the result as workflow and deployment fit, not a universal model winner.

Treat this as a product-type comparison: Claude Sonnet 4.6 is standalone API model, while GPT-5.2 Codex is coding-specialized model. Choose based on workflow fit before reading any benchmark or price row as decisive.

Decision scorecard

Local evidence first
SignalClaude Sonnet 4.6GPT-5.2 Codex
Product typeStandalone API modelCoding-specialized model
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentscustom coding agents, code generation, and tool loops
Decision fitCoding, RAG, and AgentsCoding, Agents, and Vision
Context window1m
Cheapest output$15/1M tokens$14/1M tokens
Provider routes6 tracked1 tracked
Shared benchmarks0 rows0 rows

Decision tradeoffs

Choose Claude Sonnet 4.6 when...
  • 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 procurement flexibility.
  • Claude Sonnet 4.6 uniquely exposes Structured outputs, Computer use, and Parallel agents in local model data.
  • Local decision data tags Claude Sonnet 4.6 for Coding, RAG, and Agents.
Choose GPT-5.2 Codex when...
  • GPT-5.2 Codex has the lower cheapest tracked output price at $14/1M tokens.
  • Local decision data tags GPT-5.2 Codex for Coding, Agents, and Vision.

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 Codex

Claude Sonnet 4.6

$6,150

Cheapest tracked route/tier: OpenRouter

GPT-5.2 Codex

$4,900

Cheapest tracked route/tier: Vercel AI Gateway

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

Switch friction

Claude Sonnet 4.6 -> GPT-5.2 Codex
  • Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
  • GPT-5.2 Codex is $1/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Structured outputs, Computer use, and Parallel agents before moving production traffic.
GPT-5.2 Codex -> Claude Sonnet 4.6
  • Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
  • Claude Sonnet 4.6 is $1/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Claude Sonnet 4.6 adds Structured outputs, Computer use, and Parallel agents in local capability data.

Specs

Specification
Released2026-02-172025-12-18
Context window1m
Parameters
Architecturedecoder onlydecoder only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
Commercial useCommercial use with conditionsCommercial use with conditions
Knowledge cutoff2025-122025-08

Pricing and availability

Pricing attributeClaude Sonnet 4.6GPT-5.2 Codex
Input price$3/1M tokens$1.75/1M tokens
Output price$15/1M tokens$14/1M tokens
Providers

Capabilities

CapabilityClaude Sonnet 4.6GPT-5.2 Codex
VisionYesYes
MultimodalYesYes
ReasoningYesYes
Function callingYesYes
Tool useYesYes
Structured outputsYesNo
Code executionYesYes
IDE integrationNoNo
Computer useYesNo
Parallel agentsYesNo

Benchmarks

No shared benchmark rows are currently sourced for this pair.

Deep dive

The capability footprint differs most on structured outputs: Claude Sonnet 4.6. Both models share vision, multimodal input, reasoning mode, and function calling, 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 4.6 lists $3/1M input and $15/1M output tokens on the cheapest tracked provider, while GPT-5.2 Codex lists $1.75/1M input and $14/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts GPT-5.2 Codex lower by about $1.17 per million blended tokens. Availability is 6 providers versus 1, so concentration risk also matters.

Choose Claude Sonnet 4.6 when coding workflow support and broader provider choice are central to the workload. Choose GPT-5.2 Codex when coding workflow support and lower input-token cost are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency.

FAQ

Which is cheaper, Claude Sonnet 4.6 or GPT-5.2 Codex?

GPT-5.2 Codex is cheaper on tracked token pricing. Claude Sonnet 4.6 costs $3/1M input and $15/1M output tokens. GPT-5.2 Codex costs $1.75/1M input and $14/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is Claude Sonnet 4.6 or GPT-5.2 Codex open source?

Claude Sonnet 4.6 is listed under Proprietary. GPT-5.2 Codex 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 4.6 or GPT-5.2 Codex?

Both Claude Sonnet 4.6 and GPT-5.2 Codex 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 4.6 or GPT-5.2 Codex?

Both Claude Sonnet 4.6 and GPT-5.2 Codex expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.

Which is better for reasoning mode, Claude Sonnet 4.6 or GPT-5.2 Codex?

Both Claude Sonnet 4.6 and GPT-5.2 Codex expose reasoning mode. 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 4.6 and GPT-5.2 Codex?

Claude Sonnet 4.6 is available on OpenRouter, Anthropic, AWS Bedrock, GCP Vertex AI, and Microsoft Foundry. GPT-5.2 Codex is available on Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-05-25. Data sourced from public model cards and provider documentation.