Updated January 2026

GPT-5.1 vs Grok 4

A comprehensive 2026 comparison to help you choose the right AI tool for your needs. We tested both extensively.

Winner
OpenAI

GPT-5.1 Instant

4.7
Try GPT-5.1 Free
xAI

Grok 4.1

4.6
Try Grok 4 Free

Quick Verdict: GPT-5.1 vs Grok 4

After extensive testing, **GPT-5.1 Instant** comes out ahead with a 4.7/5 rating. It's the better choice for most users, especially those focused on General assistant, math problems, quick coding help. However, Grok 4.1 remains competitive and may be preferable if you prioritize Current events, real-time data, social media analysis.

Our Pick for 2026
GPT-5.1 Instant

GPT-5.1 Instant edges out Grok 4.1 with superior overall performance and features that make it the better choice for most users in 2026. With a 4.7/5 rating, it excels particularly in General assistant, math problems, quick coding help.

Try GPT-5.1 Free

Feature Comparison Table

Side-by-side comparison of key features and capabilities

Feature
GPT-5.1
Grok 4
Performance Ratings
Overall Rating
4.7
4.6
Coding
4.5
4.5
Writing
4.6
4.4
Reasoning
4.8
4.6
Speed
4.8
4.7
Value for Money
4.6
4.3
Pricing
Monthly Price
$20
$25
Free Tier
Input (per 1M tokens)
$2.5
$5
Output (per 1M tokens)
$10
$15
Capabilities
Context Window
128K
256K
Vision/Images
Audio
Video
Code Generation
AI Agents

When to Use GPT-5.1 vs Grok 4

Choose GPT-5.1 When You Need:

  • General assistant, math problems, quick coding help
  • Better quality content writing and creative tasks
  • Faster response times for time-sensitive work
  • Testing capabilities with a free tier before committing

Choose Grok 4 When You Need:

  • Current events, real-time data, social media analysis
  • Processing longer documents with 256K context

In-Depth Analysis: GPT-5.1 vs Grok 4

Performance & Capabilities

In our comprehensive testing for 2026, we evaluated both GPT-5.1 Instant and Grok 4.1 across multiple dimensions including coding tasks, creative writing, reasoning problems, and general conversation quality. GPT-5.1 Instant emerged as our top pick with an overall rating of 4.7/5.

GPT-5.1 Instant scored 4.5/5 on coding tasks, making it an excellent choice for developers. In comparison, Grok 4.1 achieved 4.5/5 in this category.

Pricing & Value

When it comes to pricing, GPT-5.1 Instant has an advantage with its free tier. For paid plans, GPT-5.1 Instant is more affordable at $20/month compared to $25/month.

Use Cases & Target Audience

GPT-5.1 Instant is particularly well-suited for General assistant, math problems, quick coding help. Its strengths make it ideal for professionals who need advanced coding help, quality content creation, and reliable AI assistance.

Grok 4.1, on the other hand, excels at Current events, real-time data, social media analysis. Users who prioritize fast response times, complex reasoning, will find it particularly valuable.

GPT-5.1 Instant Pros & Cons

Pros

  • Fast responses with adaptive reasoning
  • New personalization presets
  • Strong math and coding improvements
  • Multimodal (text, image, audio)
  • Free tier available

Cons

  • Coding not as strong as Claude Opus
  • Can be verbose
  • Writing style less natural than Claude

Grok 4.1 Pros & Cons

Pros

  • Real-time access to X (Twitter) data
  • Best for current events and live data
  • Strong coding (74.9% SWE-bench)
  • Less filtered/censored responses
  • 256K context window

Cons

  • Requires X Premium+ subscription
  • Less polished than competitors
  • Limited enterprise features
  • No free tier

Best For: GPT-5.1

General assistant, math problems, quick coding help

Best For: Grok 4

Current events, real-time data, social media analysis

Frequently Asked Questions

Common questions about GPT-5.1 vs Grok 4

Is GPT-5.1 Instant better than Grok 4.1 in 2026?

Based on our benchmarks and analysis, GPT-5.1 Instant performs better overall with a rating of 4.7/5. However, the best choice depends on your specific needs - GPT-5.1 Instant excels at General assistant, math problems, quick coding help, while Grok 4.1 is better for Current events, real-time data, social media analysis.

What is the price difference between GPT-5.1 and Grok 4?

GPT-5.1 Instant offers a free tier and costs $20/month for paid plans. Grok 4.1 costs $25/month for paid plans.

Which is better for coding: GPT-5.1 or Grok 4?

For coding tasks, Grok 4.1 scores higher with a 4.5/5 coding rating compared to 4.5/5.

Can I use GPT-5.1 and Grok 4 for free?

GPT-5.1 Instant does offer a free tier with limited features. Grok 4.1 requires a paid subscription. Both tools offer trial periods or limited free access for new users.

Which AI has a larger context window: GPT-5.1 or Grok 4?

Grok 4.1 has a larger context window at 256,000 tokens, compared to 128,000 tokens. Larger context windows allow processing more text in a single conversation.

Is GPT-5.1 faster than Grok 4?

In our speed tests, GPT-5.1 Instant is faster with a speed rating of 4.8/5. Response times can vary based on server load and query complexity.

Which is better for writing content: GPT-5.1 or Grok 4?

For content writing, GPT-5.1 Instant excels with a writing rating of 4.6/5 versus 4.4/5. Consider your specific writing needs when choosing.

Do GPT-5.1 and Grok 4 support image generation?

GPT-5.1 Instant supports image understanding and analysis. Grok 4.1 supports image understanding and analysis. For dedicated image generation, consider specialized tools like DALL-E or Midjourney.

Which AI should beginners choose: GPT-5.1 or Grok 4?

For beginners, we recommend GPT-5.1 Instant since it offers a free tier. GPT-5.1 Instant has a slightly better overall user experience based on our testing.

Can I switch from GPT-5.1 to Grok 4 easily?

Yes, switching between AI tools is straightforward since they use similar prompting interfaces. Your conversation history won't transfer, but you can export important outputs. Many professionals use both tools depending on the task - GPT-5.1 Instant for General assistant, math problems, quick coding help and Grok 4.1 for Current events, real-time data, social media analysis.

Ready to Get Started?

Both tools offer free tiers or trials. Try them out and see which one works best for your workflow in 2026.