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AI model comparison

Claude Sonnet 4 (latest) vs GPT-Realtime-2.1

Compare pricing, context limits, supported inputs and deployment options to choose a model for your workflow.

Claude Sonnet 4 (latest) from Anthropic lists 200K context, 64K maximum output. GPT-Realtime-2.1 from OpenAI lists 128K context, 32K maximum output, $4.00 input per 1M tokens, $24.00 output per 1M tokens. Compare the inputs, outputs and deployment options below to see which fits your workflow.

Side-by-sideCapabilities and practical differences

Anthropic

Claude Sonnet 4 (latest)

Claude Sonnet 4 (latest) from Anthropic: Balanced Claude model for coding, analysis, agent workflows, and cost control.

Context
200K
Max output
64K

Accepts

  • Text input
  • Image input
  • PDF input

Produces

  • Text output
Full model profilegithub.com ↗
VS

OpenAI

GPT-Realtime-2.1

GPT-Realtime-2.1 from OpenAI: Realtime speech-to-speech model with configurable reasoning, tool use, and robust voice-agent behavior.

Context
128K
Max output
32K
Input / 1M tokens
$4.00
Output / 1M tokens
$24.00

Accepts

  • Text input
  • Audio input
  • Image input

Produces

  • Text output
  • Audio output
Full model profilegithub.com ↗

At a glance

Key differences

Compare the available figures below, then try both models on the work you need to do.

Claude Sonnet 4 (latest)

  • Context capacity: 200K
  • Maximum output: 64K

Context capacity

Higher listed limit

Claude Sonnet 4 (latest):200K

GPT-Realtime-2.1:128K

Claude Sonnet 4 (latest)

Maximum output

Higher listed limit

Claude Sonnet 4 (latest):64K

GPT-Realtime-2.1:32K

Claude Sonnet 4 (latest)

Specifications

Pricing, limits and capabilities

Specifications for Claude Sonnet 4 (latest) and GPT-Realtime-2.1. Higher limits and lower prices describe these figures only.
SpecificationClaude Sonnet 4 (latest)GPT-Realtime-2.1
ProviderAnthropicOpenAI
Listed pricing routeAnthropicOpenAI
Model familyclaude-sonnetgpt
Accepted inputstext, image, pdftext, audio, image
Produced outputstexttext, audio
Context window200KHigher128K
Max output64KHigher32K
Input price / 1M—$4.00
Output price / 1M—$24.00
Reasoning modeDocumentedDocumented
Tool callingDocumentedDocumented
Image inputDocumentedDocumented
Audio inputNot documentedDocumented
Structured outputNot documentedNot documented
LicenseProprietaryProprietary

Workload guidance

Which model should you choose?

Consider Claude Sonnet 4 (latest) if you need larger context or larger maximum output. Test both on the same representative examples and judge the output against your acceptance criteria. Include tool failures, retries and the time to a completed task.

Documentation and model profiles

Explore each model’s features, API requirements and licence terms in the sources below.

Questions people ask

It brings together documented inputs and outputs, token limits, deployment terms and available pricing. When both models have source-linked, verified results on a shared benchmark, those results are shown with their individual sources. The comparison is a starting point for evaluating your own workload.

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