Context Window

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Claude Opus 4 vs Claude Sonnet 4 6

This page is context-first: how much text each model can take in one request. Full specs adds capabilities and limits; the pricing matrix below is only about $/million tokens from hosts that list both models.

Anthropic

Model

Claude Opus 4

Image inputTool calling

Context window

410K

409,600 tokens · ~307K words

Model page
Anthropic

Model

Claude Sonnet 4 6

Image inputTool calling

Context window

1M

1,000,000 tokens · ~750K words

Model page

Context window · side by side

Bar length is relative to the larger of the two windows (100% = max of this pair). This is not pricing.

Claude Opus 4410K
Claude Sonnet 4 61M

Claude Sonnet 4 6 has about 2.4× the context window of the other in this pair.

Token calculator →Memory savings →

Claude Sonnet 4 6 has 144% more context capacity (1000K vs 409K tokens). Claude Sonnet 4 6 is 80% cheaper on input.

Quick verdicts

Short takeaways — validate with your own workloads.

  • Long document processing

    Use Claude Sonnet 4 6. Its 1000K context fits entire documents without chunking (vs 409K).

  • RAG / high-volume retrieval

    Use Claude Sonnet 4 6. Input tokens are 80% cheaper — critical when sending large retrieved contexts.

  • Long output (reports, code files)

    Use Claude Sonnet 4 6. Its 64K max output lets you generate complete artifacts in one request.

Full specs

Context, output, capabilities, and dates. Green highlights the favorable value where we compute a winner.

SpecClaude Opus 4Claude Sonnet 4 6
Context window409,600 tokens (409K)1,000,000 tokens (1000K)
Max output tokens32,000 tokens (32K)64,000 tokens (64K)
Speed tierDeepBalanced
VisionYesYes
Function callingYesYes
Extended thinkingYesYes
Prompt cachingYesYes
Batch APIYesYes
Release dateMay 2025N/A

Pricing matrix

Dollar rates only: hosts that list both models, per 1M tokens. For how much text fits, use the context section above — not this table.

ProviderClaude Opus 4 inClaude Opus 4 outClaude Sonnet 4 6 inClaude Sonnet 4 6 out
Anthropic——$3.00/M$15.00/M
Aws Bedrock——$3.00/M$15.00/M
Azure——$3.00/M$15.00/M
Gmi$15.00/M$75.00/M——
Google Vertex$15.00/M$75.00/M$3.00/M$15.00/M
Openrouter$15.00/M$75.00/M$3.00/M$15.00/M

Frequently asked questions

Claude Sonnet 4 6 has a larger context window: 1000K tokens vs 409K. For long documents, large codebases, or extended agent sessions, the larger context window reduces the need to chunk inputs or summarize history.

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Example: a multi-turn chat session

Without Mem0~128K tokens sent
Full history
Repeated info
Old context
With Mem0~20K tokens sent
Key memories
Current turn

80% less to send — works with any model