Context Window

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GPT-5.1-Codex-Max vs Jp Anthropic Claude Opus 4 7

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.

Openai

Model

GPT-5.1-Codex-Max

Image inputTool calling

Context window

400K

400,000 tokens · ~300K words

Model page
Anthropic

Model

Jp Anthropic Claude Opus 4 7

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.

GPT-5.1-Codex-Max400K
Jp Anthropic Claude Opus 4 71M

Jp Anthropic Claude Opus 4 7 has about 2.5× the context window of the other in this pair.

Token calculator →Memory savings →

Jp Anthropic Claude Opus 4 7 has 150% more context capacity (1000K vs 400K tokens). GPT-5.1-Codex-Max is 77% cheaper on input.

Quick verdicts

Short takeaways — validate with your own workloads.

  • Long document processing

    Use Jp Anthropic Claude Opus 4 7. Its 1000K context fits entire documents without chunking (vs 400K).

  • RAG / high-volume retrieval

    Use GPT-5.1-Codex-Max. Input tokens are 77% cheaper — critical when sending large retrieved contexts.

Full specs

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

SpecGPT-5.1-Codex-MaxJp Anthropic Claude Opus 4 7
Context window400,000 tokens (400K)1,000,000 tokens (1000K)
Max output tokens128,000 tokens (128K)128,000 tokens (128K)
Speed tierBalancedDeep
VisionYesYes
Function callingYesYes
Extended thinkingYesYes
Prompt cachingYesYes
Batch APINoYes
Release dateDec 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.

ProviderGPT-5.1-Codex-Max inGPT-5.1-Codex-Max outJp Anthropic Claude Opus 4 7 inJp Anthropic Claude Opus 4 7 out
Aws Bedrock——$5.50/M$27.50/M
Openrouter$1.25/M$10.00/M——

Frequently asked questions

Jp Anthropic Claude Opus 4 7 has a larger context window: 1000K tokens vs 400K. 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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Mem0 gives your AI long-term memory so you stop re-sending context on every call. That means you can use a smaller, faster, cheaper model — and still get better answers.

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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