Model Comparison

Grok-4.20 Beta Reasoning vs Grok 4.5Which is better in 2026?

Comparing Grok-4.20 Beta Reasoning and Grok 4.5 across benchmarks, pricing, and capabilities.

Verdict: Grok-4.20 Beta Reasoning vs Grok 4.5 — which is better?

Grok-4.20 Beta Reasoning (by xAI) 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.

Grok-4.20 Beta Reasoning also accepts a larger context window (2,000,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Grok-4.20 Beta Reasoning if…

  • you process long inputs — it offers a 2,000,000 token context window

Choose Grok 4.5 if…

  • you want the most recent training data — it shipped Jul 2026

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Grok-4.20 Beta Reasoning and Grok 4.5don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

For input processing, Grok-4.20 Beta Reasoning ($2.00/1M tokens) costs the same as Grok 4.5 ($2.00/1M tokens).

For output processing, Grok-4.20 Beta Reasoning ($6.00/1M tokens) costs the same as Grok 4.5 ($6.00/1M tokens).

In conclusion, Grok-4.20 Beta Reasoning and Grok 4.5 cost the same.*

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

Lowest available price from all providers
Wed Jul 29 2026 • llm-stats.com
xAI
Grok-4.20 Beta Reasoning
Input tokens$2.00
Output tokens$6.00
Best providerxAI
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-4.20 Beta Reasoning accepts 2,000,000 input tokens compared to Grok 4.5's 500,000 tokens. Only Grok-4.20 Beta Reasoning specifies output context (30,000 tokens).

xAI
Grok-4.20 Beta Reasoning
Input2,000,000 tokens
Output30,000 tokens
xAI
Grok 4.5
Input500,000 tokens
Output- tokens
Wed Jul 29 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Grok-4.20 Beta Reasoning and Grok 4.5 support multimodal inputs.

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

Grok-4.20 Beta Reasoning

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.

Grok-4.20 Beta Reasoning

Proprietary

Closed source

Grok 4.5

Proprietary

Closed source

Release Timeline

When each model was launched

Grok-4.20 Beta Reasoning was released on 2026-03-09, while Grok 4.5 was released on 2026-07-16.

Grok 4.5 is 4 months newer than Grok-4.20 Beta Reasoning.

Grok-4.20 Beta Reasoning

Mar 9, 2026

4 months ago

Grok 4.5

Jul 16, 2026

1 weeks ago

4mo newer

Knowledge Cutoff

When training data ends

Grok 4.5 has a documented knowledge cutoff of 2026-02-01, while Grok-4.20 Beta Reasoning'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 Grok-4.20 Beta Reasoning's cutoff date.

Grok-4.20 Beta Reasoning

—

Grok 4.5

Feb 2026

Provider Availability

Grok-4.20 Beta Reasoning is available from xAI. Grok 4.5 is available from xAI.

Grok-4.20 Beta Reasoning

xai logo
xAI
Input Price:Input: $2.00/1MOutput Price:Output: $6.00/1M

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

xAI
Larger context window (2,000,000 tokens)
xAI

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

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Grok-4.20 Beta Reasoning and Grok 4.5 side-by-side, then vote on the output you prefer.

Grok-4.20 Beta Reasoning
✓ Preferred
Grok 4.5
Open in Playground
AI Model Comparison Table
Feature
xAI
Grok-4.20 Beta Reasoning
xAI
Grok 4.5

FAQ

Common questions about Grok-4.20 Beta Reasoning vs Grok 4.5.

Which is better, Grok-4.20 Beta Reasoning or Grok 4.5?

Grok-4.20 Beta Reasoning (xAI) and Grok 4.5 (xAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does Grok-4.20 Beta Reasoning compare to Grok 4.5 in benchmarks?

Grok-4.20 Beta Reasoning scores Finance Agent v2: 28.5%. 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 Grok-4.20 Beta Reasoning cheaper than Grok 4.5?

Both models cost $2.00 per million input tokens.

What are the context window sizes for Grok-4.20 Beta Reasoning and Grok 4.5?

Grok-4.20 Beta Reasoning supports 2.0M 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 Grok-4.20 Beta Reasoning and Grok 4.5?

Key differences include context window (2.0M vs 500K). See the full comparison above for benchmark-by-benchmark results.

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