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Grok Code Fast 1 vs Solar Pro 4

Grok Code Fast 1 significantly outperforms across most benchmarks. Solar Pro 4 is 1.0x cheaper per token.

xAI · Upstage · Updated for 2026

Which is better?

Grok Code Fast 1 outperforms in 1 benchmarks (SWE-Bench Verified), while Solar Pro 4 is better at 0 benchmarks. Grok Code Fast 1 significantly outperforms across most benchmarks.

Solar Pro 4 also accepts a larger context window (524,288 input tokens), making it the stronger choice for long documents and large codebases.

Based on current benchmark, pricing, and model metadata for 2026.

Choose Grok Code Fast 1

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks

Choose Solar Pro 4

  • you process long inputs — it offers a 524,288 token context window
  • you want the most recent training data — it shipped Aug 2026

At a glance

The differences that matter most.

Grok Code Fast 1
xAI
Solar Pro 4
Upstage
Benchmark wins
1 of 1
0 of 1
Input price
$0.20 / M
$0.30 / M
Output price
$1.50 / M
$1.20 / M
Context window
256,000
524,288
Released
Aug 2025
Aug 2026
License
Proprietary
Proprietary

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Grok Code Fast 1 outperforms in 1 benchmarks (SWE-Bench Verified), while Solar Pro 4 is better at 0 benchmarks.

Grok Code Fast 1 significantly outperforms across most benchmarks.

Mon Aug 24 2026 • llm-stats.com

Arena Performance

Playground indexes and blind preference scores

Pricing Analysis

Price comparison per million tokens

Solar Pro 4 costs less

For input processing, Grok Code Fast 1 ($0.20/1M tokens) is 1.5x cheaper than Solar Pro 4 ($0.30/1M tokens).

For output processing, Grok Code Fast 1 ($1.50/1M tokens) is 1.3x more expensive than Solar Pro 4 ($1.20/1M tokens).

In conclusion, Grok Code Fast 1 is more expensive than Solar Pro 4.*

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

Lowest available price from all providers
Mon Aug 24 2026 • llm-stats.com
xAI
Grok Code Fast 1
Input tokens$0.20
Output tokens$1.50
Best providerxAI
Upstage
Solar Pro 4
Input tokens$0.30
Output tokens$1.20
Best providerUnknown Organization
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Solar Pro 4 accepts 524,288 input tokens compared to Grok Code Fast 1's 256,000 tokens. Solar Pro 4 can generate longer responses up to 131,072 tokens, while Grok Code Fast 1 is limited to 10,000 tokens.

xAI
Grok Code Fast 1
Input256,000 tokens
Output10,000 tokens
Upstage
Solar Pro 4
Input524,288 tokens
Output131,072 tokens
Mon Aug 24 2026 • llm-stats.com

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Grok Code Fast 1

Proprietary

Closed source

Solar Pro 4

Proprietary

Closed source

Release Timeline

When each model was launched

Grok Code Fast 1 was released on 2025-08-28, while Solar Pro 4 was released on 2026-08-06.

Solar Pro 4 is 11 months newer than Grok Code Fast 1.

Grok Code Fast 1

Aug 28, 2025

12 months ago

Solar Pro 4

Aug 6, 2026

2 weeks ago

11mo newer

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

Grok Code Fast 1 is available from xAI. Solar Pro 4 is available from Upstage.

Grok Code Fast 1

xai logo
xAI
Input Price:Input: $0.20/1MOutput Price:Output: $1.50/1M

Solar Pro 4

upstage logo
Unknown Organization
Input Price:Input: $0.30/1MOutput Price:Output: $1.20/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Grok Code Fast 1 and Solar Pro 4 side-by-side, then vote on the output you prefer.

Grok Code Fast 1
✓ Preferred
Solar Pro 4
Open in Playground

FAQ

Common questions about Grok Code Fast 1 vs Solar Pro 4.

Which is better, Grok Code Fast 1 or Solar Pro 4?

Grok Code Fast 1 significantly outperforms across most benchmarks. Grok Code Fast 1 is made by xAI and Solar Pro 4 is made by Upstage. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Grok Code Fast 1 compare to Solar Pro 4 in benchmarks?

Grok Code Fast 1 scores SWE-Bench Verified: 70.8%. Solar Pro 4 scores AIME 2026: 95.3%, GPQA: 89.0%, LiveCodeBench: 87.8%, MMLU-Pro: 86.3%, AA-LCR: 71.0%.

Is Grok Code Fast 1 cheaper than Solar Pro 4?

Grok Code Fast 1 is 1.5x cheaper for input tokens. Grok Code Fast 1 costs $0.20/M input and $1.50/M output via xai. Solar Pro 4 costs $0.30/M input and $1.20/M output via upstage.

What are the context window sizes for Grok Code Fast 1 and Solar Pro 4?

Grok Code Fast 1 supports 256K tokens and Solar Pro 4 supports 524K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Grok Code Fast 1 and Solar Pro 4?

Key differences include context window (256K vs 524K), input pricing ($0.20 vs $0.30/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok Code Fast 1 and Solar Pro 4?

Grok Code Fast 1 is developed by xAI and Solar Pro 4 is developed by Upstage.

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