Model Comparison

GPT-5.4 vs Grok Code Fast 1Which is better in 2026?

Comparing GPT-5.4 and Grok Code Fast 1 across benchmarks, pricing, and capabilities.

Verdict: GPT-5.4 vs Grok Code Fast 1 — which is better?

GPT-5.4 (by OpenAI) and Grok Code Fast 1 (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.

On price, Grok Code Fast 1 is roughly 10.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5.4 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose GPT-5.4 if…

  • you process long inputs — it offers a 1,000,000 token context window
  • you want the most recent training data — it shipped Mar 2026

Choose Grok Code Fast 1 if…

  • cost matters — it's about 10.7x cheaper per token
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Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

GPT-5.4 and Grok Code Fast 1 don'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

Grok Code Fast 1 costs less

For input processing, GPT-5.4 ($2.50/1M tokens) is 12.5x more expensive than Grok Code Fast 1 ($0.20/1M tokens).

For output processing, GPT-5.4 ($15.00/1M tokens) is 10.0x more expensive than Grok Code Fast 1 ($1.50/1M tokens).

In conclusion, GPT-5.4 is more expensive than Grok Code Fast 1.*

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

Lowest available price from all providers
Sun Jun 07 2026 • llm-stats.com
OpenAI
GPT-5.4
Input tokens$2.50
Output tokens$15.00
Best providerOpenAI
xAI
Grok Code Fast 1
Input tokens$0.20
Output tokens$1.50
Best providerxAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5.4 accepts 1,000,000 input tokens compared to Grok Code Fast 1's 256,000 tokens. GPT-5.4 can generate longer responses up to 128,000 tokens, while Grok Code Fast 1 is limited to 10,000 tokens.

OpenAI
GPT-5.4
Input1,000,000 tokens
Output128,000 tokens
xAI
Grok Code Fast 1
Input256,000 tokens
Output10,000 tokens
Sun Jun 07 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-5.4 supports multimodal inputs, whereas Grok Code Fast 1 does not.

GPT-5.4 can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT-5.4

Text
Images
Audio
Video

Grok Code Fast 1

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.

GPT-5.4

Proprietary

Closed source

Grok Code Fast 1

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5.4 was released on 2026-03-05, while Grok Code Fast 1 was released on 2025-08-28.

GPT-5.4 is 6 months newer than Grok Code Fast 1.

GPT-5.4

Mar 5, 2026

3 months ago

6mo newer
Grok Code Fast 1

Aug 28, 2025

9 months ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

GPT-5.4 is available from OpenAI. Grok Code Fast 1 is available from xAI.

GPT-5.4

openai logo
OpenAI
Input Price:Input: $2.50/1MOutput Price:Output: $15.00/1M

Grok Code Fast 1

xai logo
xAI
Input Price:Input: $0.20/1MOutput Price:Output: $1.50/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

OpenAI
Larger context window (1,000,000 tokens)
Supports multimodal inputs
xAI
Less expensive input tokens
Less expensive output tokens

Detailed Comparison

AI Model Comparison Table
Feature
OpenAI
GPT-5.4
xAI
Grok Code Fast 1

FAQ

Common questions about GPT-5.4 vs Grok Code Fast 1.

Which is better, GPT-5.4 or Grok Code Fast 1?

GPT-5.4 (OpenAI) and Grok Code Fast 1 (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 GPT-5.4 compare to Grok Code Fast 1 in benchmarks?

GPT-5.4 scores Tau2 Telecom: 98.9%, ARC-AGI: 93.7%, Graphwalks BFS <128k: 93.0%, GPQA: 92.8%, Graphwalks parents <128k: 89.8%. Grok Code Fast 1 scores SWE-Bench Verified: 70.8%.

Is GPT-5.4 cheaper than Grok Code Fast 1?

Grok Code Fast 1 is 12.5x cheaper for input tokens. GPT-5.4 costs $2.50/M input and $15.00/M output via openai. Grok Code Fast 1 costs $0.20/M input and $1.50/M output via xai.

What are the context window sizes for GPT-5.4 and Grok Code Fast 1?

GPT-5.4 supports 1.0M tokens and Grok Code Fast 1 supports 256K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-5.4 and Grok Code Fast 1?

Key differences include context window (1.0M vs 256K), input pricing ($2.50 vs $0.20/M), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.4 and Grok Code Fast 1?

GPT-5.4 is developed by OpenAI and Grok Code Fast 1 is developed by xAI.

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