What is the main difference in context size between GPT-5 and Grok 4?

GPT-5 provides a 400,000‑token context window, while Grok 4 offers 256,000 tokens. This means GPT-5 can process substantially longer inputs—such as extensive codebases or documents—without truncation, whereas Grok 4 handles moderately sized inputs but with a smaller overall capacity.

Which model is better for coding tasks?

GPT-5 is explicitly noted for advanced coding capabilities alongside reasoning and tool use, suggesting stronger performance in code generation and debugging. Grok 4’s published capabilities list reasoning and tool use but do not highlight coding, so GPT-5 is likely the more suitable choice for programming‑focused workloads.

Are the weights of GPT-5 or Grok 4 publicly available?

Both models are released with closed weights, meaning the underlying parameter files are not made publicly available for download, modification, or fine‑tuning by end users. Access is typically provided through the developers’ APIs or hosted services.

Do GPT-5 and Grok 4 support multimodal input?

Yes. Both models are described as multimodal, indicating they can process inputs that combine text with other modalities such as images. This enables use cases like visual question answering or image‑guided reasoning.

Which model should I choose for general reasoning and tool use?

If your primary need is strong reasoning coupled with reliable tool integration, Grok 4 is explicitly positioned as a reasoning flagship with those capabilities. GPT-5 also offers reasoning and tool use but adds a coding focus and larger context, which may be unnecessary for purely general reasoning tasks.

Comparison · Updated Aug 26, 2026

GPT-5 vs Grok 4

GPT-5 (OpenAI, 2025) and Grok 4 (xAI, 2025) are closed‑weights, multimodal LLMs; GPT-5 offers a 400k‑token context and advanced coding, while Grok 4 provides a 256k‑token context focused on reasoning.

Model A

GPT-5

OpenAI's next-generation flagship model succeeding GPT-4o.

Aug 7, 2025

Model B

Grok 4

xAI's Grok 4 reasoning flagship.

Jul 9, 2025

Differences

Attribute	GPT-5	Grok 4
Developer	OpenAI	xAI
Released	2025-08-07	2025-07-09
Context window	400000 tokens	256000 tokens
Open weights	false	false
Modality	Multimodal (text & vision)	Multimodal (text & vision)
Capabilities	Advanced reasoning, coding, tool use	Reasoning, tool use
Best for	Advanced coding and large‑context tasks	General reasoning and tool‑based workflows

Verdict

Developers who need extensive coding support and the largest possible context may favor GPT-5, whereas users whose primary need is strong reasoning and tool use within a slightly smaller context may find Grok 4 sufficient.

Analysis

Overview GPT-5 and Grok 4 are both large language models released in mid‑2025 by prominent AI labs. Each model is a closed‑weights system, meaning the underlying parameters are not publicly available for download or modification. Both support multimodal input, allowing them to process text alongside images or other modalities. Their core purpose is to serve as versatile foundations for applications ranging from chatbots to code assistants.

Where they differ The most quantifiable distinction lies in context length. GPT-5 provides a 400,000‑token window, substantially larger than Grok 4’s 256,000‑token capacity. This enables GPT-5 to ingest longer documents, extended codebases, or extensive conversation histories without truncation. Regarding capabilities, GPT-5 is highlighted for advanced reasoning, coding, and tool use, suggesting a stronger emphasis on programming assistance and complex logical tasks. Grok 4 lists reasoning and tool use as its strengths, with no explicit mention of coding prowess, implying a focus more on general problem‑solving and interaction with external tools. Developers may also note the differing pedigrees: GPT-5 stems from OpenAI’s lineage following GPT-4o, while Grok 4 is xAI’s flagship reasoning model, reflecting different research priorities and training data mixes.

Which to choose If your workflow demands handling very large inputs—such as analyzing entire repositories, lengthy legal contracts, or multimodal datasets—and you benefit from strong code generation, GPT-5’s larger context and coding emphasis make it the preferable option. Conversely, if you prioritize robust reasoning and reliable tool integration while operating within a more moderate context size, Grok 4 offers a capable alternative. Ultimately, the decision hinges on whether the extra 144k tokens and coding focus of GPT-5 justify its selection over the reasoning‑centric design of Grok 4.

Frequently asked

What is the main difference in context size between GPT-5 and Grok 4?: GPT-5 provides a 400,000‑token context window, while Grok 4 offers 256,000 tokens. This means GPT-5 can process substantially longer inputs—such as extensive codebases or documents—without truncation, whereas Grok 4 handles moderately sized inputs but with a smaller overall capacity.
Which model is better for coding tasks?: GPT-5 is explicitly noted for advanced coding capabilities alongside reasoning and tool use, suggesting stronger performance in code generation and debugging. Grok 4’s published capabilities list reasoning and tool use but do not highlight coding, so GPT-5 is likely the more suitable choice for programming‑focused workloads.
Are the weights of GPT-5 or Grok 4 publicly available?: Both models are released with closed weights, meaning the underlying parameter files are not made publicly available for download, modification, or fine‑tuning by end users. Access is typically provided through the developers’ APIs or hosted services.
Do GPT-5 and Grok 4 support multimodal input?: Yes. Both models are described as multimodal, indicating they can process inputs that combine text with other modalities such as images. This enables use cases like visual question answering or image‑guided reasoning.
Which model should I choose for general reasoning and tool use?: If your primary need is strong reasoning coupled with reliable tool integration, Grok 4 is explicitly positioned as a reasoning flagship with those capabilities. GPT-5 also offers reasoning and tool use but adds a coding focus and larger context, which may be unnecessary for purely general reasoning tasks.