Context Window

Compare

Gpt 5 3 Chat Latest vs Grok 4 20 Non Reasoning

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 3 Chat Latest

Image inputTool calling

Context window

128K

128,000 tokens · ~96K words

Model page
Xai

Model

Grok 4 20 Non Reasoning

Image inputTool calling

Context window

2M

2,000,000 tokens · ~1.5M 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 3 Chat Latest128K
Grok 4 20 Non Reasoning2M

Grok 4 20 Non Reasoning has about 15.6× the context window of the other in this pair.

Token calculator →Memory savings →

Grok 4 20 Non Reasoning has 1462% more context capacity (2000K vs 128K tokens). Gpt 5 3 Chat Latest is 12% cheaper on input.

Quick verdicts

Short takeaways — validate with your own workloads.

  • Long document processing

    Use Grok 4 20 Non Reasoning. Its 2000K context fits entire documents without chunking (vs 128K).

  • RAG / high-volume retrieval

    Use Gpt 5 3 Chat Latest. Input tokens are 12% cheaper — critical when sending large retrieved contexts.

  • Long output (reports, code files)

    Use Grok 4 20 Non Reasoning. Its 2000K 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.

SpecGpt 5 3 Chat LatestGrok 4 20 Non Reasoning
Context window128,000 tokens (128K)2,000,000 tokens (2000K)
Max output tokens16,384 tokens (16K)2,000,000 tokens (2000K)
Speed tierBalancedDeep
VisionYesYes
Function callingYesYes
Extended thinkingYesNo
Prompt cachingYesYes
Batch APINoNo
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.

ProviderGpt 5 3 Chat Latest inGpt 5 3 Chat Latest outGrok 4 20 Non Reasoning inGrok 4 20 Non Reasoning out
Google Vertex——$2.00/M$6.00/M
Openai$1.75/M$14.00/M——

Frequently asked questions

Grok 4 20 Non Reasoning has a larger context window: 2000K 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.

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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