Context Window

Compare

Gov Anthropic Claude Sonnet 4 5 20250929 vs Gpt 4o Realtime Preview 2025 06 03

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

Gov Anthropic Claude Sonnet 4 5 20250929

Image inputTool calling

Context window

200K

200,000 tokens · ~150K words

Model page
Openai

Model

Gpt 4o Realtime Preview 2025 06 03

Tool calling

Context window

128K

128,000 tokens · ~96K 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.

Gov Anthropic Claude Sonnet 4 5 20250929200K
Gpt 4o Realtime Preview 2025 06 03128K

Gov Anthropic Claude Sonnet 4 5 20250929 has about 1.6× the context window of the other in this pair.

Token calculator →Memory savings →

Gov Anthropic Claude Sonnet 4 5 20250929 has 56% more context capacity (200K vs 128K tokens). Gov Anthropic Claude Sonnet 4 5 20250929 is 34% cheaper on input.

Quick verdicts

Short takeaways — validate with your own workloads.

  • Long document processing

    Use Gov Anthropic Claude Sonnet 4 5 20250929. Its 200K context fits entire documents without chunking (vs 128K).

  • RAG / high-volume retrieval

    Use Gov Anthropic Claude Sonnet 4 5 20250929. Input tokens are 34% cheaper — critical when sending large retrieved contexts.

  • Long output (reports, code files)

    Use Gov Anthropic Claude Sonnet 4 5 20250929. 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.

SpecGov Anthropic Claude Sonnet 4 5 20250929Gpt 4o Realtime Preview 2025 06 03
Context window200,000 tokens (200K)128,000 tokens (128K)
Max output tokens64,000 tokens (64K)4,096 tokens (4K)
Speed tierBalancedBalanced
VisionYesNo
Function callingYesYes
Extended thinkingYesNo
Prompt cachingYesYes
Batch APIYesYes
Release dateN/AN/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.

ProviderGov Anthropic Claude Sonnet 4 5 20250929 inGov Anthropic Claude Sonnet 4 5 20250929 outGpt 4o Realtime Preview 2025 06 03 inGpt 4o Realtime Preview 2025 06 03 out
Aws Bedrock$3.30/M$16.50/M——
Openai——$5.00/M$20.00/M

Frequently asked questions

Gov Anthropic Claude Sonnet 4 5 20250929 has a larger context window: 200K tokens vs 128K. For long documents, large codebases, or extended agent sessions, the larger context window reduces the need to chunk inputs or summarize history.

Powered by Mem0

Use a smaller model.
Get better results.

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.

Calculate your savingsLearn about Mem0

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