Model Comparison

ChatGPT-4o Latest vs Grok 4.5Which is better in 2026?

Grok 4.5 significantly outperforms across most benchmarks. Grok 4.5 is 1.5x cheaper per token.

Verdict: ChatGPT-4o Latest vs Grok 4.5 — which is better?

ChatGPT-4o Latest (by OpenAI) and Grok 4.5 (by xAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

ChatGPT-4o Latest outperforms in 0 benchmarks, while Grok 4.5 is better at 1 benchmark (GPQA). Grok 4.5 significantly outperforms across most benchmarks.

On price, Grok 4.5 is roughly 1.5x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Grok 4.5 also accepts a larger context window (500,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose ChatGPT-4o Latest if…

  • you want predictable pricing at $2.50/M input and $10.00/M output

Choose Grok 4.5 if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • cost matters — it's about 1.5x cheaper per token
  • you process long inputs — it offers a 500,000 token context window
  • you want the most recent training data — it shipped Jul 2026

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

ChatGPT-4o Latest outperforms in 0 benchmarks, while Grok 4.5 is better at 1 benchmark (GPQA).

Grok 4.5 significantly outperforms across most benchmarks.

Mon Jul 27 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Grok 4.5 costs less

For input processing, ChatGPT-4o Latest ($2.50/1M tokens) is 1.3x more expensive than Grok 4.5 ($2.00/1M tokens).

For output processing, ChatGPT-4o Latest ($10.00/1M tokens) is 1.7x more expensive than Grok 4.5 ($6.00/1M tokens).

In conclusion, ChatGPT-4o Latest is more expensive than Grok 4.5.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Mon Jul 27 2026 • llm-stats.com
OpenAI
ChatGPT-4o Latest
Input tokens$2.50
Output tokens$10.00
Best providerOpenAI
xAI
Grok 4.5
Input tokens$2.00
Output tokens$6.00
Best providerxAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Grok 4.5 accepts 500,000 input tokens compared to ChatGPT-4o Latest's 128,000 tokens. Only ChatGPT-4o Latest specifies output context (16,384 tokens).

OpenAI
ChatGPT-4o Latest
Input128,000 tokens
Output16,384 tokens
xAI
Grok 4.5
Input500,000 tokens
Output- tokens
Mon Jul 27 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both ChatGPT-4o Latest and Grok 4.5 support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

ChatGPT-4o Latest

Text
Images
Audio
Video

Grok 4.5

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

ChatGPT-4o Latest

Proprietary

Closed source

Grok 4.5

Proprietary

Closed source

Release Timeline

When each model was launched

ChatGPT-4o Latest was released on 2024-05-13, while Grok 4.5 was released on 2026-07-16.

Grok 4.5 is 26 months newer than ChatGPT-4o Latest.

ChatGPT-4o Latest

May 13, 2024

2.2 years ago

Grok 4.5

Jul 16, 2026

1 weeks ago

2.2yr newer

Knowledge Cutoff

When training data ends

Grok 4.5 has a documented knowledge cutoff of 2026-02-01, while ChatGPT-4o Latest's cutoff date is not specified.

We can confirm Grok 4.5's training data extends to 2026-02-01, but cannot make a direct comparison without ChatGPT-4o Latest's cutoff date.

ChatGPT-4o Latest

—

Grok 4.5

Feb 2026

Provider Availability

ChatGPT-4o Latest is available from OpenAI. Grok 4.5 is available from xAI.

ChatGPT-4o Latest

openai logo
OpenAI
Input Price:Input: $2.50/1MOutput Price:Output: $10.00/1M

Grok 4.5

xai logo
xAI
Input Price:Input: $2.00/1MOutput Price:Output: $6.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

OpenAI

No standout differentiators in the data we have for this pair.

xAI
Larger context window (500,000 tokens)
Less expensive input tokens
Less expensive output tokens
Higher GPQA score (93.0% vs 84.0%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against ChatGPT-4o Latest and Grok 4.5 side-by-side, then vote on the output you prefer.

ChatGPT-4o Latest
✓ Preferred
Grok 4.5
Open in Playground
AI Model Comparison Table
Feature
OpenAI
ChatGPT-4o Latest
xAI
Grok 4.5

FAQ

Common questions about ChatGPT-4o Latest vs Grok 4.5.

Which is better, ChatGPT-4o Latest or Grok 4.5?

Grok 4.5 significantly outperforms across most benchmarks. ChatGPT-4o Latest is made by OpenAI and Grok 4.5 is made by xAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does ChatGPT-4o Latest compare to Grok 4.5 in benchmarks?

ChatGPT-4o Latest scores GPQA: 84.0%. Grok 4.5 scores GPQA: 93.0%, Terminal-Bench 2.1: 83.3%, Artificial Analysis Coding Agent Index v1.1: 76.0%, SWE-Bench Pro: 64.7%, AA-Omniscience Index: 63.0%.

Is ChatGPT-4o Latest cheaper than Grok 4.5?

Grok 4.5 is 1.3x cheaper for input tokens. ChatGPT-4o Latest costs $2.50/M input and $10.00/M output via openai. Grok 4.5 costs $2.00/M input and $6.00/M output via xai.

What are the context window sizes for ChatGPT-4o Latest and Grok 4.5?

ChatGPT-4o Latest supports 128K tokens and Grok 4.5 supports 500K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between ChatGPT-4o Latest and Grok 4.5?

Key differences include context window (128K vs 500K), input pricing ($2.50 vs $2.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes ChatGPT-4o Latest and Grok 4.5?

ChatGPT-4o Latest is developed by OpenAI and Grok 4.5 is developed by xAI.

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